*DISCLAIMER*: The various evil in this post about things you can do to your car may have certain side effects:
-Destruction of "street legality"
-Increased wear on/destruction of: tires/gas/clutches/pistons/transmissions/various other parts
-Dying in a firey crash to be covered by all of 30 seconds of local news coverage at two in the morning because you have the driving skills of a blind retarded carrot.
Bottom line: Be smart and realistic. Know your limits in all things. Mechanically (don't take your engine apart to swap pistons if you can't open a juice box), financially (don't try to drop $4000 on turbos if you work at McDonalds for minimum wage) and most importantly, don't overdrive your skill level. Go to the track and take some learning courses. Get into kart and club racing. Learning to drive a car fast and hard safely is 200% above and beyond knowing how to make the car go around a corner. Don't forget that when you are upgrading a car, if you are paying for it yourself, you are essentially pissing money down the drain. Most people can only get about half or even a third the upgrade money> out of the car when then go to sell it (IE, $15,000 car with $15,000 worth of go-fast parts for sale for $20,000). Keeping you stock parts and removing the aftermarket stuff to sell off is advised if you ever get rid of the vehicle, you might get half or ever three quarters of your money then. And given that you decide to proceed with said money wasting procedures, make sure you have a defined goal in mind and plan out how to get to that goal before you make any purchases. Yeah it might be cool to say you have big, high tech turbos in your car but if you don't plan on doing an engine build you probably won't be able to take full advantage of them and it's a waste of money. The easiest way to go about it is to have a defined purpose in mind for the car. Whether it be cruising, car shows, auto cross, drag, drift, road coursing or whatever, study up on the cheapest, easiest, safest way to get there. Also, if you plan to do any of the work below yourself, get a factory service manual. They can be expensive, up to $150 if you have to buy from a dealership, but it will pay for itself every time you don't have to spend five hours in the middle of the night staring at something trying to figure out where it goes, how it works and what’s wrong with it. Or, you know, buy a manual on CD off ebay for like $10. Or at the very least become familiar with the online versions:
Dat iz som handee shat yo.
Getting to 3rd Base: A Stage 3 TT is generally considered an intake, cat-back and ECU upgrade, giving you an extra 80-100hp at around 11-14psi of boost. This translates into 280-315rwhp depending on the condition of the car and boost. Just about anyone with simple tools and half a brain can do these upgrades. I’ll go more in depth in this section just because this is as far as most people will go. I'll list NA potential gains here too since all these apply to the non-turbo as well. Please note that gains are only estimate and lean to the optimistic side.
First off, the cheap stuff:
Single Cone Intake: Pretty obvious, increases the rate at which your engine can inhale life giving oxygen. Many people make them, some of the better ones are the Jim Wolf (K&N), HKS, Apexi and so on. This will run you about $100-$150 dollars for a good, washable, reusable filter. All it requires to install is removing the nose panel, unbolting the stock air box and putting in the higher flowing unit. Some recent flow testing. (http://twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=1006295)
Estimated Power Gain-NA: 5-10hp TT: 10-20hp
Cat-back exhaust: Well known every where cars are found. Increases exhaust flow, keeps the emissions required catalytic converters in place. These systems range in price, flow, and style but unless you’re flowin big power, the power difference between any two given systems is usually small. Borla, B&B, and Specialty Z all make great exhausts but there are many more on the market. A single tip straight through exhaust usually will out flow a dual tip though. Prices are anywhere from $500 to $1500. Installing will mean jacking up the car, unbolting the stock system from the cats and juggling the new pieces into place.
Estimated Power Gain-NA: 10hp TT: 20hp
ECU: Remapped computer. This is not so much a power upgrade as it is a safety issue, making it safer for your engine to run hard at higher boost. They do this by modifying timing retard and air/fuel ratio under boost. There is a variety places to get this if you are looking for a bolt in: Specialty Z, Jim Wolf, AshSpec, Ztuner, Z from Japan and a few other shops.Specialty Z and Jim Wolf's is probably the best known and most widely used. And also remember there are other places that sell performance chips and whole ECUs so look around but beware of bad merchandise from shady outfits. There are some sellers that just take a stock chip and reprogram it to run rich or even do nothing more than remove the stock rev limiter and then try to sell them as "performance tuned".
-The stock computer is located under a wood panel on the passenger side, pull back the carpet from under the dash to see it. All you have to do is unbolt the old ECU from its bracket and the wiring harness connector end. Put the new one in its place and put all the bolts back where you found them.
-For the TT owners, you’ll usually get a set of boost jets with the ECU that partially block the air flow to the waste gates, letting you run more boost, usually about 12-14psi. These are small, round pieces of metal with a hole in the center that install in the wastegate hose that attaches to the "out" side of the intercooler piping. An aftermarket boost gauge is highly recommended at this point so you can keep an eye on the boost. The balance tube on the top of the intake plenum to the rear has a hose off the left end that feeds the stock boost sensor. This can be T’d into and the connecting end for the new gauge installed. There is a hole in the firewall between the clutch and brake pedals or there is a few on the passenger side that you can route the hose/tube/wire through up to an aftermarket gauge.
Boost controllers: As mentioned above, you can up the boost with some restrictors. However this is not an overly great way to manage the air flow. A much better idea is a boost controller, which I’ll talk about more later on, so if you’re looking to go past a few simple upgrades then it’s a wise investment.
Estimated Power Gain-NA: 10hp TT: 40-60hp (~11-14psi)
At this point you'll probably be putting out around 300rwhp and a good driver should be able to run consistent mid-13s in the 1/4 even without a dedicated drag setup. You probably have around $1500-$2000 invested in upgrades right now.
Going farther: Now we get into things that require more serious disassembly to install, a decent wrench with enough tools and some Z32 experience will be fine, automotive gimps add extra for labor costs.
Underdrive pulley: This is slightly more work, you have to pull all of the accessory belts and usually the radiator. If you can do this with a timing belt change, do so. This will add another 10-15hp or so to your TT, mostly in the top end, because this pulley is smaller, which reduces the speed at which all the other pulleys run thus cutting the load on the engine. It will also be lighter, taking less time to accelerate than the heavy stock pulley. This upgrade runs $200 for the crank pulley or $400 for the whole set, both of which should include the different belt packages you’ll need to run these smaller pulleys.
-Note about UD pulleys: The stock pulley is equipped with a harmonic damper that basically absorbs the vibrations from the crank that occur as the pistons fire and progressively load and unload the crank with thousands of pounds of force. With one or two exceptions (such as the Fischer or ATI), an UD pulley is not going to have this. However, this has never been a problem with the VG as they are much more naturally balanced then say an inline 4 cylinder or other V6s. This is mostly due to their straight through firing order that loads the next cylinder as the one before it is unloaded. The stock tolerances on weight and balance are also pretty tight for a production motor. Many UD pulley equipped VGs have 50,000+ miles on them with no problems. However, if you do want a damper equipped pulley for peace of mind, the ATI pulley is a solid option.
-As the idea of the UD pulley is to reduce drag by lowering the accessory rpm, which means it slows the water pump. Whether or not this will be a problem is specific to each car so make sure you have some way to check the actual sensor measured temperature of the coolant (not just the stock gauge on the dash) at least periodically (even something like Datascan or ConZult). If you find yourself with temperature problems then the ready made solution is an over drive pulley for the water pump, which will bring it up to stock rpm.
Down pipes: These replace the stock pre-cats that are located directly behind the turbos. The pre-cats are hulking cast iron disasters made up of bottle necks, ninety degree bends and fail so putting a nice open pipe in there really helps to spool your turbos faster. However, installing these can be a pain in the ass, if you can’t do it yourself then you better add some money in for labor costs. These will run you anywhere from $150-$800. Specialty Z "Super Split" down pipes are the favorite for those with the money to buy them. If you want the best of the best Specialty Zs new 3” expansion down pipes offer absolutely the best flow on the market. For those with less disposable income a set of first generation split down pipes is a good option. Another even cheaper option, as in free cheap, is gutting the pre-cats, kind of a ghetto down pipe. This involves removing the pre-cats and basically pounding out the catalytic bricks inside. The pre-cats are still going to flow bad compared to an aftermarket down pipe but this will make them fail a little less. Though you can usually sell your pre-cats to a metal scrapper for a bit of cash that you can put towards a cheap set of down pipes so there really isn’t a reason to do this.
-Down pipes can be installed with the transmission in if you like exercises in suffering and anger. With the transmission out it becomes approximately one thousand time easier so down pipes usually are done with an upgraded clutch.
Test pipes: Removing the last of the turbo-back stock exhaust. These fit between the down pipes and the cat back and will add a little more power than the down pipes but at the cost of your emissions required catalytic converters. You can get pre-made, ready to order test pipes with high-flow cats already welded in if the car still needs to pass smog, but naturally, with the cats still on there the gains will be slightly smaller and the pipes more expensive. Figure these to be $150-500 and a 15hp gain without cats, $400-600 and a 10hp gain with. Since this section of exhaust is just a tube with a flange on each end, fitment is a bit less critical then the downpipes. So if you feel lucky you can search around for the cheaper pipes but remember that you tend to get what you pay for.
Note: If you install down pipes with the cats still in you’ll feel a nice gain. If you install test pipes with the pre-cats still in you’ll feel a nice gain. If you do both you’ll feel a big gain. Getting both of those blockages out of the exhaust really helps spool the turbos. I’ve got just about all of these basic upgrades on my Twin Turbo and now with the test and down pipes just about any throttle at all in 3rd gear or higher will build boost. And yes, that makes the car an abso-fuckin-lutely absurd amount of fun to drive.
Clutch: At this point the stock clutch will start slipping under heavier boost loads, so we upgrade to stronger bits. A clutch kit for this level will run around $350-500 dollars and will be stiffer then the stock one. The JimWolf, RPS and Southbend DXD clutches are commonly used in the Z32 community. A standard disc will be usually be preferred for a street car but if you plan to do a decent amount of tracking or hard launches at a drag strip then consider a puck style disc.
Flywheel: While you have your transmission out for the clutch and the down pipes you can add a lightened flywheel to cut rotating mass. The flywheel acts as an energy storage device (the large mass of the flywheel helps keep the motor spinning to make it easier to drive) and the heavier it is the longer it takes to accelerate it. A stock unit is 25lbs or so and most aftermarket units are in the 12-15 lbs range so you can see how big a difference this can make. This will run about $400-500. The RPS segmented flywheel is a great product and many advocate the Jim Wolf/Fidanza flywheel as well.
-Note: There are some situations where a heavy flywheel is preferred, such as drag racing. However most people will likely find the lighter aftermarket flywheels an improvement over stock. Even with a light weight crank pulley and flywheel on my car (taking off ~25 lbs of the engine rotating mass) the open-closed throttle transition is not bad.
Intercoolers: The stock intercoolers should be switched for higher flowing units around this time (if not before now) to feed the increasingly hungry turbos. It will drop intake air temp a good deal, making it safer to run higher boost and create an easier passage through the intake system. This will run around $600-1000 and only requires the removal of the front bumper and related items. Some aftermarket intercoolers will need new duct work to force the air through them. And while many would look at the few large front mount kits that are offered for the Z32, an upgraded pair of side mounts that use the stock positioning will tend to work best. HKS, Greddy, Stillen, T0Ms Turbo, Ashspec…look around and find what works for you.
-If you’re interested in a front mount then a different bumper, like the 99 Jspec, is probably in order as the stock bumper with its low profile front opening is probably going to cut off half of the intercooler. The GReddy, Border and T0Ms Turbo (http://tturbo.net/) front mounts are probably the way to go if you really want one. Things to be considered: intake filter clearance, cooling system capacity (since you are now dumping a huge amount of heat across the front of the radiator) and air flow requirements, for the engine and across the front of the IC.
At this level you have a car generally known as a "Stage 5+" Z, basically all the big, easy bolt-on mods you can do. Your Z is probably putting down upwards of 340-370rwhp now and 12 second 1/4 miles are with in reach given some sticky tires and slick driving. Upgrading has sucked approximately $3000-$5000 out of your pocket by now. This really isn't a bad place to stop. The small stock turbos and the mods you have done should give you little to no turbo lag, you have plenty of power, you haven't spent A LOT of money on upgrades and daily drivability is still pretty good. Suspension and brakes should be on your mind at this point.
Going beyond kid stuff: We are now getting to the limit of the stock fuel injectors and unaided pump gas. At point this you start getting into engine pulling, disassembly and possibly rebuilding. Professional machining is required for some of this work, and unless you are a good mechanic with a small shop worth of tools at your disposal, you’ll have to find a real shop to do a lot of this. Also, by this point, you are looking at having your engine/car in pieces for extended periods of time. You can install a set of downpipes over an afternoon in your driveway but it will take you a while to rebuild the heads. If you are going to pull the upper plenum or do an engine pull make sure you have: Another car to get around in, a clear concept of what you’re doing and why and a place to work and have stuff spread out in a manner where it's not going to get damaged or lost.
Have money too.
Fuel injectors: The stock 370cc units aren’t going to go beyond 15psi or so and thus we upgrade. Nismo units are generally considered to be the best however PE injectors are also quality. Also available and cheaper, DeatschWerks injectors can be made to work with the stock fuel rails and they aren’t huge in the Z community but a number of other commonly modded cars use them regularly. The Nismo units come in 555cc (90-94), 615cc (95-96) and 740cc (95-96) units, for this level, 555ccs or 615ccs will probably be all you’ll need. Either of these sets will run about $900. So why not get the larger 740ccs just for the hell of it? If you are running injectors that are oversized for your power level it can actually decrease power and increase risk of detonation and engine damage as larger injectors are less accurate in terms of precise fuel delivery. If you need the 740ccs for your 90-94 engine, you're looking at swapping the fuel injector wiring harness connectors with 95-96 model connectors and replacing or machining the lower intake plenum to match the newer style injector and fuel rail. You also have to do some work on the intake port of the 90-94 heads to match the larger port of the 95-96 lower intake plenums. To go beyond the range of the 740ccs, and we're talkin really big power here, Power Enterprises makes a 850cc injector set that will handle anything short of an utter max power attempt. Though it’s likely if you have to go beyond 740s you’re also going to be beyond 850s. How much power do you need you greedy bastard?
-There has been issues with the earlier model (90-94) 555cc fuel injector style failing. This doesn't mean all 90-94 injectors are time bombs waiting to **** up your engine but if it is something you are concerned about then simply update to the newer style. It has been found that the early style fuel injectors are sensitive to the recent switch to gasoline mixed with ethanol in some states.
-300Degree has come out with a set of bolt-on upgrade fuel rails for the Z. They can fit a variety of aftermarket fuel injectors and will flow enough for just about anything. They’ve been extensively flow tested and computer modeled to deliver constant and stable fuel pressure to each injector.
ECU upgrade: To run those larger injectors you’ll need to swap out the chip on your aftermarket ECU. $100 or so depending on where you source the chip and many times you can find the chip you need included with the next upgrade.
Dual intake: You'll want to split the intake pipes so you have one feeding each turbo once you get past 375rwhp or so. You can do it before this point but its not going to add too much extra power, most post around a ~10rwhp gain. The Jim Wolf unit is widely used. To run this upgrade you’ll need to alter the ECU, which is easily done while you’re upgrading the fuel injectors. This upgrade ranges from $300 to $600 depending on what is included in the specific kit.
-Note: The best way to go about adding a dual intake is to run a dual MAF setup as well. That way all the air coming into the motor is measured rather than guessed at. To do this you’ll need a second MAF (duh), associated wiring and some kind of aftermarket go-between, like the Apexi SAFC II, to handle the additional sensor.
Gauges and controllers: Once you start getting up in power it becomes more and more vital that you know what is going on in the engine and have more control over it. A basic boost controller and gauge will suffice for now but looking into more advanced units that can give you data on and control air-fuel ratios, engine timing and other engine vitals is a good idea and will be required further down the line, not to mention being vital to getting the most out of your car with custom tuned injection maps and such. For a basic boost controller the GReddy Profec line is popular for its simplicity and price. For upgraded turbos and higher boost applications the Blitz SBD-III is the common choice. Getting a fuel controller and wide band O2 is not a must at this point but if you want to dyno or just dial in your setup read the tuning section towards the bottom.
Some stuff you want to keep an eye on:
-Oil pressure (the stock gauge may or may not be trust worthy, check your sensor)
-Boost (stock gauge is not detailed enough when you get up passed 15psi or so)
-Oil temp - good to know but usually if the oil is getting much hotter than it should (250+ degrees) then you have bigger problems
-Water temp - not as critical as the first four but good to know, especially if you live some place hot, track your car or have an underdrive pulley
Oil coolers and radiator: If you live in a hot climate or track your car, you may want to install a higher capacity oil cooler and radiator at this point to shed some of the extra heat your engine is going to be putting out. A radiator will run you around $400. Nismo sells the European spec oil cooler, which was about 3 times larger, Stillen has a nice oil cooler for around $200 but if you don't mind making a few connectors you can get a more generic model and fit it to your system for less. These are not really "must have" upgrades right now but if you find yourself with overheating problems and can't find fault in the cooling system then this is the next step.
-For those so inclined, the best oil cooler and radiator setup in a mostly stock configuration will be a radiator with the oil cooler integrated into it. Check out SPLparts.com to see a full list of advantages and options.
Water/Alcohol injection: Basically it’s a little nozzle that shoots water into your intake. Yep, water in the engine. Sounds bad does it not? But the amount of water is limited, a very light mist being shot into the hot dry air flowing through the intake. Its purpose is to cool the air being fed into the engine and help reduce uncontrolled detonation of the fuel in the cylinder (the power of the exploding gas in the confined area is incredible, if all the working bits inside aren't at the right place when the gas lights off serious damage can be done, to the point of literally blowing an engine to pieces). With the risk of detonation lowered, you can run more boost. Not a huge amount more but enough to see substantial power increases. And it’s just a good idea to be as safe as you can when you are talking about adding a lot of power to an engine. Alcohol-Water injection is basically the same as straight water injection except with the added cooling power alcohol brings. I'm not going to go into it in too much detail here because it basically needs to be tailored to your car for the best effect. If you are going to get a custom ECU chip or tune your engine management then it would be best to add any type of water/alcohol injection system you are going to run and tune the car with the system active. This goes double for a water/alcohol system as the methanol will be acting as a second fuel source and can throw off your air-fuel ratio.
-Most systems are designed to come on only after a certain amount of boost has been reached. More advanced systems are paired with a custom ECU and take into account: throttle position, fuel/air ratio, intake air and fuel temps, and a few other factors that can be programmed in. This is one of those things you just have to tune relentlessly for the greatest effect. But even just a simple system set up to inject X amount at Y boost and only uses a simple progression of X+1 amount at Y+1 boost will do wonders for performance. This can be done at any time during upgrading, even just going from stock to make it safer to up the boost on stock injectors and pump gas. However this usually does not come into play until boost levels start getting higher with upgraded turbos.
The following items will require an engine pull. Only ye experienced VG wrenches tread here. If you are having a performance shop do the work be warned: labor costs on a pull can be huge, sometimes equaling the cost of parts. If you are doing the work yourself, be warned you are now getting into taking things apart that: A. Don't like being taken apart B. Will cost you serious money to fix or replace and C. Could cause serious damage to the car and you if you get it put together wrong.
Aftermarket exhaust manifolds: There are a few cast iron manifolds on the market as well as some tubular steel manifolds, all of which offer an vast performance increase in flow and spool over the stock manifold. Mike Smith Performance is probably the most popular, offering excellent flow and rock solid reliability for ~$700. This is really something that going to be determined by what you plan to do with the car.
-If you don’t want to drop the cash on any of them, you can get ported stock manifolds for about $400 and they will help reduce lag and increase top end power as well as fatten your power band but not in anyway as dramatic as any of the aftermarket manifolds. Basically if you are dropping huge money on an engine build, cams and turbos etc and so on it makes sense to get some kind of manifold too. To me anyway.
Turbos: Yeah, that’s right, we’re talking badass SOBs now. It can be hard to select the correct turbo for a given car, even more so if there isn’t a clear picture of what is wanted from the car. This is going to be a big investment in cash and is one of the primary factors in the feel of the car. Do a lot of research on this before choosing and remember that each car is different so a turbo set that makes 500rwhp on one car may make 540 on another or only 430 on a third car. A lot of that variation has to do with the supporting upgrades done to the car (exhaust manifolds, cams, etc). Again, it’s very important to have a well thought out plan for what the car is going to be used for and select a turbo based on the requirements of the task. The best way to select a turbo is bust out the math and the compressor maps but that’s another FAQ in itself. For more information on that try these places:
The stock turbos: They're small. They spool so fast they'll make boost with nothing but a good hooker attached to one end. But as a smaller turbo, they're only going to flow so much air. They're pretty good up to about 15-16 psi, so if that’s all you plan to run, by all means, keep the little buggers and save your money. However, if you want more than 375-400rwhp-ish then you'll have to upgrade. Chances are that if you are reading this, "turbo upgrade" is the first thing that crosses your mind whenever you're not thinking about boobs, as rare as that might be for some people. Anyway, you can find a decent low mile set of stock turbos fairly cheap, $500ish for a pair depending on miles and condition, usually from someone doing a turbo upgrade, or rebuilt ones for a bit more. However, rebuilt turbos tend not to have a great track record. If you’re going the rebuild route, just get new center sections and reuse the compressor and turbine housings. A pair of new CHRAs (center housing rotating assemblies) will cost around $900. Brand new in the box OEM turbos retail for about $1800 for a set. Very few people find that price tag palatable given that you can get a better set for almost the same money.
FYI: The turbine housing A/R ratios on the automatic transmission Twin Turbos were slightly smaller, .54 to the manual cars .63. That means the auto turbos will spool a bit faster but on a fairly well modified car they’ll probably be a bit of a restriction in the top end, though not a hell of a lot more than the .63s.
As for upgrading, the generally accepted brand name turbos for this range are:
-Jim Wolf Sport 500: A good stock replacement, a decent power upgrade. 500s should produce about 50-75 more rwhp then stock with almost no increase in lag. They use the stock housings with a new CHRA. These can get you upwards of 450rwhp and run about $1500-$2000.
-Jim Wolf 530BB: A newer, more advanced ball bearing turbo. These are Garrett’s GT2554R turbo that have been modified to bolt on. Specialty Z has gotten 520rwhp with these using their upgraded manifolds and from what I’ve seen, that was without performance cams, a lot of ECU tuning or port work on the cylinder heads, so more may be obtainable, perhaps even into the 550rwhp range. This is probably the fastest spooling turbo commonly used on the Z. $2900ish
-PE 1420: One of the less widely used turbos, the 1420s are ball bearing units and a good balance of power and lag, netting upwards of 550rwhp. These are priced $2400-$2900 depending on the kit and supplier.
-Jim Wolf Sport 600: An older turbo on the market, they are still highly potent. The right tuning can get you upwards of 550rwhp. Pricing is usually around $2500 but as they are plain bearing turbos and are larger then 530s or GT2530s so they tend have more lag.
-HKS GT2530: These have netted in the range of 500rwhp with some well tuned, heavily modified cars getting upwards of 580rwhp. Also a ball bearing unit, they tend to have more lag than the 530BBs but have been proven to make more power. In a nut shell, the 2530 is a modified GT28RS. These run about $3800-$4200 and come with varying amounts of gaskets, tubing and related hardware depending on the source of the turbos.
-GReddy TD05: One of the largest turbos for this range, they can make upwards of 600 rwhp and come with a set of stainless steel exhaust manifolds for quicker spool up as well as the various gaskets and tubes you’ll need. Kits run around $4200-$4500.
There are many other turbos out there for the Z32, I've only listed some of the more main stream ones. If you can do a bit of fab work on brackets and oil/coolant lines then you can get just about any turbo you want and mount it up to your car. Probably the most talked about generic turbo fitment is the GT28R turbo (GT2560R), which can be had for $1300-$1500 a set straight from a Garrett distributor.
Cams and valve springs: Since you are going to have the engine out for the turbos then you might look into installing a set of performance cams and the required performance valve springs. There are a few different cams on the market and their prices are roughly the same, about $1000 for the performance cams plus about $350 for performance valve springs. Jim Wolf does offer a mild set of cams for about $600 that can use the stock springs, making the install almost bolt in compared to swapping springs. Obviously these aren't going to make as much of a power difference as the bigger cams but it’s much easier. However, given a higher mileage engine, it is a sound idea to replace the springs, be it performance or stock, as they get worn over time. If you are getting the stiffer springs or just replacing the stocks, it will most likely require a professional install. This is because they are pressed together as a package of spring, valve, oil seal, retainer and etc all stuffed down into a little hole under the lifters. It takes some specialty equipment and training to pull it all apart and put it back together right. By comparison, replacing the just the cams is really simple, just pop the valve covers off, pull the cam gears and there they are…once you remove the upper plenum, all the associated wires, take out the radiator, all the drive belts, the timing belt…you get the idea.
-You can do cams before getting all the way to engine pulls and turbo upgrades but it will make less of a difference at lower levels. At stock, a set of cams may give you a mere 10-15 hp boost. However at higher levels, they can add 30-40rwhp through out most of the power band, improve upper rpm range performance dramatically, quicken spool up and improve throttle response. There are many advantages but usually not unless you are going big.
-Another thing about cams, they will change how the engine responds dramatically. Cams determine where the power starts, how hard the engine revs through a certain range and last but not least how the car drives at low speeds. Performance cams are setup to deliver power in the mid or upper rpm ranges while most stock cams are setup for good idle and low end power. Cams designed for max power may cause slight hesitation and will take some of the power out of the low end. Also, as you are changing the duration of the intake and exhaust, you may push your car over the limit as far as emissions tests are concerned.
Forged Pistons: Even though they are cast pieces, the stock pistons can take a hell of a beating so this is not an absolute if you are going for the 400-500rwhp range (assuming your engine is in at least fairly good shape). There are Z owners running 25+psi of boost and 700+rwhp on the stock bottom end. How is it done? Tuning, tuning, tuning and more tuning. It's all about tuning the engine correctly to avoid piston killing detonation. With a safe air/fuel ratio and a good timing advance map, you can run just about any amount of power you want on a stock short block. Sheer power output is not going to destroy a motor, not at least until you get into massive power. But it’s always good to make everything stronger. The stock cast pistons are not going to hold up against detonation at higher power levels. The sooner an engine build is done, the less you'll worry later on after you have the car together, afraid to push your new turbos hard because you don't want to fracture a piston if you start getting engine knock. If you are going to run more than 500rwhp with any amount of frequency and are doing an engine rebuild anyway then you’ll probably want to install some forged pistons. The stock cast pieces are coming up on the edge of reliability at this point and there is no sense blowing a motor when you can get a full set of forged pistons for $600.
-This will almost certainly require professional installation unless you happen to be a professional with a machine shop in your garage so better add some money for that, how much will vary depending the shop and the condition your engine is in. At this point your engine is in pieces so make sure you have a place for everything if the whole thing isn’t in a shop somewhere.
-One thing you may want to look into while you’re doing pistons is anti-heat and anti-friction coatings. It costs around $200 to get the six set coated with a ceramic (anti-heat) top and moly (anti-friction) side coat. That can save an engine, especially one that runs as hot as the VG. A set of good, low mile stock pistons that have been heat coated and balanced will be good for all but the highest power applications given proper tuning. Overkill is good when building an engine but there is no point in dropping a lot of cash on forged pistons and all of the required machining if your power levels don't really need it.
Connecting rods: The stock Z32 rods are some of the strongest stock rods ever put into a production engine and are good till 600rwhp or better so this is also not a "must have" upgrade. You can get a good set of lightweight forged rods (Eagle H beams for example) for about $600 with the pieces needed to put it all together which should include a trick ass set of ARP rod bolts. If you are going to use the stock rods (and have them reconditioned to proper length) then you can pick up the ARP rod bolt set for $60 (highly recommended).
A word about built engines: People tend to refer to an engine with all forged and balanced internals as "bullet proof". Stupid can destroy anything. While a built engine is going to be able to take more abuse, nothing is fool proof. A well tuned stock engine will be safe to 500rwhp or better. A fully built engine tuned by Jack Mehoff is a grenade at stock boost levels.
Going big or going home: When doing an engine build you have a lot of options as to how far to go and how much money to spend. A typical full rebuild with just a set of forged pistons will run $2000-$3000 for the long block depending on the shop you go to and any stock pieces that need to be replaced. Obviously some things (like gaskets, rear main seal, cam seals etc) are all going to need to be replaced but given a low mile engine and moderate power goals you can reuse the stock lifters, water pump and things like that. However, given higher power goals and longer parts lists you can spend upwards of $4000-$5000 on the short block easily and have upwards of $7500 in the complete long block. Add all the other pieces of the engine in and you can have $10,000 invested in the engine very quickly even without an expensive pair of turbos on it.
Other engine parts and work: To put in the pistons you’ll need to straighten the cylinders and clean the walls up, which needs to be done at a machine shop. That costs money. Also while it’s out you should replace the main and rod bearings and have the crank checked. That’s more money. And when you go to put it together you’ll want a new head gasket set (stock head gaskets are enough for just about anything) and some good ARP main and head bolts. Yup, that’s more money. Call around to local shops for prices on labor or shop around the net for pre-built engines. Kyle at IPP builds some of the best VGs around and Specialty Z has a golden reputation with the engines they’ve built.
-The internal casting of the VG block tends not to be that great. Particularly the main coolant gallery behind the water pump. Using a long Dremel attachment or whatever you deem appropriate you can knock most of the bigger chunks off and improve the flow through there a lot. You do have to be very careful to hose the block out thoroughly to get all of the shavings so this is best done after the block has been stripped but before it heads off to the machine shop.
-While you are taking everything apart, getting your intake plenums honed internally (polished to increase airflow) and a set of ported heads can boost the power. A boxed up ready to ship set of intake plenums can be found at www.stillen.com, however you must trade your original plenum to them or double the cost with a core charge. The head porting is usually done at a local shop that knows what it’s doing, this can be expensive so check around for rates. Head porting is still a bit of an art rather than a hard “check table A for your engine porting requirements” type of science. Properly porting heads requires knowledge of the physics behind airflow and understanding things like the relationship between the volume and velocity of moving air. I will point out that the stock 300ZX heads flow pretty good for stock bits and there isn't too much in the way of actually widening the ports that can be done before you hit the gasket. Also, having seen VG cylinder heads that have been cut open, there isn’t a huge amount of metal between where the air flows and where the fluid flows, so you must be very careful not to get a section of wall too thin. Mostly head work for a VG30 means polishing up the interior to flow easier. It’s not really a must do item but it does help increase air flow through the engine and since the engine is apart and you are spending all this money anyway...what’s another bit of cash right?
-Warning about extrude honing or other wise opening up your intake plenums: If you do that without touching the heads then the edge of the intake port on the cylinder head will stick out around your newly widened extrude honed plenum. Just remember whatever you end up doing get the ports on the plenums and heads the same size.
-On that note, if you want to tweak your plenums a bit without dropping a lot of cash something you can do is bolt the upper and lower plenums together before engine assembly. Using a long neck Dremel, round file or whatever else you have to, start shaving away the metal that hangs out where the plenums don't exactly match up. Once they are matched up, take some sanding wheels on your Dremel or just some sandpaper and smooth out what you can reach of the plenums. After doing this be sure to clean the metal shavings and dust out of the plenums thoroughly. You can do the same thing by bolting up the lower plenum to the heads but if you do remember that it's very important to keep the by products of the process contained to be cleaned out. Overall, it's not going to make a big difference, but if you are strapped for cash and want to give your Z as much of a boost as you can, it's something to consider.
-Your stock fuel pump is better than most aftermarket pumps and flows enough for about 600rwhp. Also note that the stock pump is a three speed piece, meaning it operates on low voltage then kicks into high gear when making boost. An aftermarket pump usually runs full voltage the entire time, giving some pumps an annoying high pitched whine at low speeds. For those that require more pump, a common option is to run dual stock pumps.
-If you are going to be doing a rebuild anyway spend the money on new heater hoses, a complete gasket set and all that happy crap. No sense putting only new pistons in a 150,000 mile engine because everything else will still have 150,000 miles on it. A bit of money and time spent while the engine is out can save hours and hours of work later. Especially if you are doing a swap or replacement with a JDM motor, as they tend not to be in great shape.
-Getting good replacement motors is getting harder and harder as the years roll on. Most will either have high miles or will have sat somewhere for years. Now depending on what you plan to do with the car you can make the choice to rebuild the replacement motor while it is out or just drop it in. If you just plan on cruising, it’s not a problem to drop in a motor that already has 60,000 miles on it. Getting the motor to replace the blown one in your "one 1/4 mile too many" weekend toy? Probably want to rebuild that one before putting it into service. And speaking of which, if you have high miles and a good block (as in no pistons have exited the block involuntarily) then it is usually cheaper and easier to get the engine rebuilt rather than replaced. An overbore on the cylinders, block cleaning, head rebuild and all that other work that will bring a long block up to virtually show room new condition shouldn't cost more than $2000-$2500, the cost of a front clip and just a little more expensive than used replacement motor. Another major plus of this is now you have a motor with no miles that you can be sure is good and you can drop in some forged pistons and whatnot while you are rebuilding and have a solid bottom end to play with. AND by going the rebuild route you keep the available pool of engines larger for us all, doesn't that make you feel all warm and socially responsible inside?
Your new engine and you: You've saved and waited and built and ordered and slaved away and you finally have it. You're engine is the shizznit. Titanium rods, big cams, heat coated everything, flowed heads, oversized valves...and zero miles. And that presents a problem/opportunity. Any good engine builder will tell you that the key to power and reliability is ring seal. Don't break your engine in properly and you'll suffer low compression for the rest of the engine's life span. It's not going to blow up on you but it won't be putting out what it could have and the motor isn't going to last as long.
So then, that being said, how do we ease our slick new power plant into the world? Well that’s where the war starts. Some people will give you exact mileages and procedures to follow, others will tell you outright that if it's going to run hard it's going to run hard and not to worry about it and there is those who recommend whipping on it immediately. This is really something that has to be taken on a case by case basis, considering the material of the parts used, the machining style used, tolerances used and what the car was built for. Consult with your engine builder for recommendations because quite frankly there is too much conflicting information out there for me to cover it all. Suffice to say, given a general rebuild using mostly OEM parts and machining techniques, follow some general guidelines and you should be alright:
-When starting for the first time, don't "prime" the engine by cranking with the starter first to get oil into the pump. You just end up extending the time the engine is spinning with no oil pressure. Just start it up and watch the oil pressure gauge, if it doesn't come up within ten seconds then shut it off and find the problem. Remember, you have assembly lube on everything and this is why you put it there. If you want to do it in what I would call the correct way I would borrow a pre-pressurizing tank from an engine shop. It's just an air tank that you dump oil in then pressurize. You then hook it up to the motor and the oil in the tank is forced into the oil pump, oil passages and heads of the motor.
-Most cam manufacturers recommend that the first 20 minutes of the engines life should be spent at around ~2000 rpm to keep the oil pressure up with no load on the engine, IE, not driving it.
-Figure a good break in window is 1000 miles, excessive by some standards but a good round number to go by
-Don't rev the engine hard, keep it under 4000 rpm
-Don't go wide open throttle on it during that first 1000
-Don't let the engine idle or remain at one rpm for long periods of time
-Get a hundred or so miles on it and change the oil.
-Change the oil again at 250, 500 and then at 1000 miles or whenever you think it's ready
-Pay very close attention to any knocking, squeaking, groaning, scraping and any other noises not meant to come from an engine. Getting to a problem quickly will usually save the motor in the long run
Leader 4.10 rear dif gears: Richmond Gears produces a 4.10 ratio ring gear and pinion set designed by Leader Gears. These will reduce your final drive ratio and improve acceleration more than just about any other upgrade except an aftermarket turbo set. The gears run around $700. It's easiest and best to drop the rear end from the car and take it to a shop for the install. These are available only in limited runs, so when they’re sold out, they’re sold out and you have to wait for a set to come up for sale or wait until the next batch that may or may not happen.
Non-turbo rear differential: The stock Twin Turbo rear end houses 3.692 gears and the stock NA is 4.083. This does require swapping out the entire rear sub-frame for a NA model, NA axels and robbing the speed sensor off a NA transmission. The reduction will improve acceleration at the cost of top end speed. Run the math and it shows you'll lose around 20mph in the top end. But that’s still around 170 mph so it's not a big concern.
Tuning: It is true that an engine and car as a whole are made up of component parts and we have to individually upgrade these parts however it takes more than throwing together a bunch of expensive, sticker clad hop up parts to get the most out of your car. The manufacturers listed power gains are a decent indication of what you’re getting into but after the first round of simple bolt on parts, all bets are off. Thus you need to hone the brain of your car (fuel injection maps, ignition advance/retard, air fuel ratios and etc) to get all these pieces from various companies working together properly, especially once you start getting into turbo upgrades, upgraded manifolds and all that happy crap. Meaning: strapping your car to a dyno, cracking open the ECU and hooking it up to a computer to find the optimum settings. An off the shelf ECU upgrade is performance tuned compared to a stock piece but each individual car will be unique even among the same model and that aftermarket ECU has to work in all of them. So isn't going to be the ideal setup for yours. You may be getting lean spots and hesitation because of intake and exhaust upgrades. BOVs can cause rich off throttle conditions. Boost controllers and AFCs alter what’s being fed into the engine in dramatic and some times harmful ways. A custom tuned chip can for the most part eliminate all that and get power from what were dead spots in the power band. If you are going far enough to upgrade the turbos, I would strongly recommend dropping some money to get a custom tuning done.
A basic tuning setup will consist of some kind of air/fuel controller (AFC. That will give you enough information and control to get on a dyno and do something productive rather that just find out how much power you’re making. It’s prudent at this point to have some kind of wideband O2 to keep an eye on your air/fuel ratio. From there, the only limit is your wallet. Wide band controllers, data logging, display systems and eventually full stand alone ECU setups.
Note: Once you get to this point you have to start thinking about engine management as a system. If you simply add a new device to cover each small section of performance tuning you can quickly end up with a cluster **** of mismatched equipment and over lapping capabilities. Many companies design their equipment to work together and so it can be best to get a full suite of electronics from one company. Do some research and figure out what your needs are and what will work best with your car.
Wide band O2s: Your basic OEM O2 sensor is referred to as a narrow band sensor. Essentially it’s built to read one air/fuel ratio point and can only tell the ECU if it’s above or below that point. A wide band O2 will actually measure the A/F ratio and let you monitor it while tuning the fuel injection map. There is a huge range of wide band gauges and controllers on the market so shop around to find the setup that suits your needs and compliments your other systems. Here are some places to look:
Air/fuel controllers: These modify the signal going to the fuel injectors to input more or less fuel as you specify. This is used in conjunction with a wide band O2 to keep your engine in a happy spot (usually somewhere between 11:1 to 11.75:1 air/fuel ratio) under boost. This does not replace the stock ECU in any way, it simply gives you the ability to adjust the fuel curve a bit one way or the other. The Apexi SAFC II and AFC Neo are popular for price and relative ease of use.
NisTune: This is a daughter board that gets soldered in place on your existing ECU and allows total tuning through the stock Consult connection. Yeah, that kicks ass. It can even log external 0-5 volt inputs like digital oil pressure gauges and such.
The Zemulator: The Zemulator goes in place of the ECU chip in your performance tuned ECU. Just plug it in and it will run with the program already in it. Now, hop your happy ass on a dyno and proceed with a base run. Plug the cable off the Zemulator chip into a computer loaded with the Zemulator program that comes with the chip and proceed to tune to your hearts content. Fuel maps, ignition timing, injector size, intake type, just about anything and everything can be tweaked as needed. At a price of $600 for chip, cable and program, this is a relatively cheap solution for full engine tuning. The only caveat is that it still uses the stock ECU so if you’re running a dual intake or wide bands you’ll still need the appropriate hardware to control those pieces.
Bikirom: http://www.bikirom.com/ is another fully adjustable ECU product on the market.
AEM EMS: Total stand alone. This handy tool replaces your stock ECU. It can receive a variety of inputs (dual MAF, MAP, wideband O2, etc), is more adjustable than play dough and works with a variety of tuning aids. At $1500-$2000, it’s expensive but if you’re going big enough it can pay huge dividends.
Emulators: You can get aftermarket chips that have a serial connection that can be hooked up to a computer. One of the better combinations an emulator like the Ostrich (http://www.moates.net/product_info.php?cPath=50&products_id=169) and a program like TunerPro. (http://tunerpro.markmansur.com/)
Running with the Big Dogs: After you start getting past 600rwhp you start getting into the limits of a lot more stock systems. Fuel pump, transmission and a few other things you really don’t want to have go out on you. Once you get to this point, you’re reaching the limits of off the shelf parts and you have to start more custom set ups. Nitrous spool kits come in here to help reduce the lag of the huge turbos needed to produce this kind of power.
Fuel system: The stock fuel pump is good for 600rwhp or so, provided it's in good condition. After this point you can get an aftermarket high flow unit or depending on the power goals, run a dual pump system. The dual pump is popular because all of the pieces can be sourced relatively easily and there a number of people that have gone before you on this one. It’s also popular because the stock TT pump flows more than a lot of aftermarket pumps anyway. I’ve only seen it on one site so don’t take this as gospel but the stock pump is suppose to be rated at 270 lph.
-The stock fuel rails, though really not that great, will flow enough for most people. Usually they are ditched because the larger fuel injectors you'll need will at some point no longer fit into the stock rails. Power Enterprises 850cc kit for example comes with its own set of rails. The 300Degree rails are a good option at this point.
Engine: A performance engine build is going to be required for these power levels. And there is going to be more work done at this level then there was at the previous.
-Forged pistons, perhaps of lower compression (for example: 8.0:1 rather than stock 8.5:1), and forged rods are definitely going to be found here. Increasing the bore may be something to think about.
-Upgraded valve springs and a big cam set are probably going to be a part of this. A high lift, long duration cam will move power to the top of the engines rpm range, which is where the larger turbos will need the extra air flow and where a cam set will likely see the most benefit. This may take a chunk of power out of the low end but usually those going for huge power numbers are putting all they have in the top end anyway. Something you might want to look into is solid lifters and upgrading the valves and retainers to stronger and lighter material if you are trying to push huge power or get 8000 rpm out of your engine.
-There are a lot of little details that can prove beneficial when building a high performance engine. For example: nitrating the cam lobes. A dry sump oil system. Knife edging the crank. Anti -heat, anti-friction, heat dispersion and all manner of other coatings. The list is virtually endless and limited only by what you know about and how much money you want to spend.
Intake: Larger intercoolers will definitely be required. Water/alcohol injection is recommended at this point. There are oversized throttle bodies available for the VG, usually in the 60mm range. However given the length of the intake piping, you pretty much have to upgrade the whole system from filter to throttle body to see any substantial gains. Border has a 60mm pipe kit, T0Ms Turbo has a great 2.5” kit at a great price and AshSpec is coming out with a line of intake pipes.
Turbochargers: You are now getting into some really massive turbos. Not massive in the context of the ginormous shells a single turbo Supra might run but very massive considering you only have 1.5 liters pushing it. All of these turbos require substantial engine building and supporting upgrades to perform at their best.
Jim Wolf 700BB: This latest piece is the GT28RS turbo modified to bolt-on and renamed the 700BB. These turbos put some serious power to the ground, upwards of 700rwhp given the appropriate supporting upgrades. There is a choice of housings, either .64 or .86. Most people opt for the .64 housing as it lends it self to quicker spooling. They run around $3300.
PE 1820: A big ass turbo from Power Enterprises. ~$3500
GT2871R: Going the next step up from a GT28RS. This setup is going to have a substantial amount of lag but it can produce over 900rwhp with the right tuning and supporting upgrades.
GT3071R: This is a big turbo. This is a 900-1000rwhp kind of turbo set. If you’re thinking of this then you have a huge amount of disposable income and enjoy the hell out of custom fabrication or have a shop that does.
Drivetrain: At this point you’re making enough power to start breaking things downstream of the engine. A clutch for this kind of power is going to be rated for 700lbsft or more. You may want to consider a carbon disc clutch if you’re going racing often as they can take a huge amount of abuse at the cost of being very costly.
-The stock drive shaft has never been a problem when it comes to holding up to power however if you have a high mileage vehicle with some slop in the drive shaft U joints then you’ll probably want to get it rebuilt or replaced. If you go aftermarket make sure you get something rated for big power and then some.
-The rear axles have only been known to break under a hard launch with drag slicks . If you’re going to be at the strip a lot and have Huge Power then you may look into cyro treating or some other way to beef them up.
Suckin’ air: The Z32 NA
Actual upgrades for the NA are limited, without forced induction you’re pretty much stuck with whatever external upgrades you can do before you are looking at a complete engine rebuild for more power and probably a really big nitrous bottle. As listed in the basic upgrade section at the top, an intake, cat-back and ECU are all going to be on your list. The under drive pulley, flywheel upgrade and a set of test pipes will help here as well. Now what?
Tubular Headers: A set of stainless steel or coated steel headers can really free up your NA engine, to the point of making another 20hp. These can be installed while the engine is in the car however doing so will be the cause of much swearing. This can run you upwards of $600. That being said, you will see much smaller gains from these if you already have a full aftermarket exhaust. If you have a set of test pipes and a good cat back, your upgrade money is probably best spent on something else.
If you've done the headers, test pipes, and cat-back, your NA is probably going to be loud as a mother****er. Check your local noise ordnances.
Okay so that’s done, what else?
Nitrous: Obviously an option, the stock bottom end can withstand upwards of a 100hp shot of the cold juice. Only real problem here is that even "bolt on" kits usually require a certain amount of modification or even fabrication of fitment parts. This should probably be left to a shop if you aren't equipped and skilled enough for the task. Also, nitrous is illegal in some places, in extreme cases they'll impound your car if you have an armed system (read: bottle valve open and ready to go). And of course, when the bottle is empty it’s probably time to head home. As a side note: to run large shots of nitrous you will almost always need large bottles. Large bottles lose pressure quickly, reducing the effectiveness of your system as you continue to use it.
-With nitrous comes the need for more fuel. Easy enough, simply grab a set of stock Twin Turbo fuel injectors and you're in business, given you have the appropriate ECU to run them. Luckily enough, if you are getting into the nitrous stage of upgrading, you should have already invested in an aftermarket ECU, of which there are many already setup to run nitrous.
Okay we got our boost for off line or the dash to the finish, what can we do now. Well, not much. At this point you're really starting to look at having to rebuild and the engine to run bore/stroker kits with larger, higher compression pistons and of course you can add ever increasing amounts of nitrous to the plan. That costs a lot of money. And really, you're not going to get much for that money. A tricked out NA engine, absolutely built to the hilt with every trick in the book will probably make some where in the area of 300rwhp. The best I've seen on a NA VG with a stock bottom end was 228rwhp with just about every upgrade you could think and a good tune on an air/fuel controller. Of course you can add another 150 with nitrous but that’s temporary. And you are passing out of anything in the range that could be called "streetable".
-So about your NA…you probably shouldn’t focus on engine upgrades too much. Cat-back, intake filter, and maybe a UD pulley. After that you’re really looking at getting smaller and smaller gains for the money, time and effort. Suspension upgrades tend to provide better overall vehicular performance gains for the non-turbo crowd.
A word about boost: It is possible to run boost on the stock NA 10.5:1 compression ratio. Not a lot of course and you have to be very careful about how you go about this and expect to have problems along the way. You'll be limited to about 8-10 psi or so even with all precautions taken. That’s not a lot of boost in the context of the 30+psi the higher power twin turbos push but fortunately it doesn't take much to give you a lot more power. And since you are using small turbos to make a small amount of boost with higher compression pistons, turbo lag shouldn't be any kind of a problem. Or there are other options, like supercharging for example. This is along the lines of the Vortech systems for the S2000 and the 350Z. They both have high compression pistons and only run 6 psi or so but as you can see from the results they've posted, it can increase power like little else can. Even just 5 psi of boost can make another 75hp. To go this seldom walked path expect to do a lot of fabricating and tuning on your own or shelling out big dough to have someone do it for you.
The VH45DE engine swap: This has been done by a few people and there is apparently even a kit in the works, though I haven’t heard anything about dates and prices. The engine is the aluminum block 4.5 liter V8 out of an Infiniti Q45. Lighter than a VG30DETT and equipped with DOHC, 32 titanium valves, forged crank/rods/pistons and some other heavy duty hardware. The latest ones make 340hp even with the Q45s luxury biased tuning. A good intake and exhaust setup should make about 380hp. Add to that some turbos, about 10psi of boost (with the needed anti-detonation precautions) and some other performance upgrades and you should be sitting in the mid 400rwhp range or better pretty easy. To go much further than that boost wise you'll have to take the engine apart and lower the compression ratio with some different pistons. This has swap has a lot of potential with its modern design and increased displacement.
It is not a kit, not yet anyway. Thus you're looking at fabricating engine mounts, exhaust pieces, transmission mounting, wiring bits, doing some custom ECU work and probably some other stuff too. Also, as you may have noted, it’s the VH45DE, not the VH45DETT. You want those turbos (or a supercharger as the case may be) then you are looking at a custom setup there as well. This is not a project for beginners. Also, as the Q45 was never thought of as a performance car, there are no ready made performance cams, exhaust manifolds or anything else waiting to be ordered, not that I have seen. Pretty much to go this route you are on your own so if you have money, skills, balls and a torch: have at it.
The RB26DETT: It’s been done, mostly in cars going for drag racing but it’s been done. There is actually a website devoted to it so if this interests you: wait til I find the damn link.
Going fast bulimic style
Everyone knows that if you drop weight your car will benefit in just about every way possible. This is especially true with cars that have little to no power (*cough*CIVIC*cough*), which tends not to be a problem with a Twin Turbo Z. But even your 600rwhp Z32 will benefit from a lessening of the mass. As far as sports cars of the era go, the Z32 was not a light weight but it wasn't a sumo wrestler either. Ranging from 3300 to 3500 lbs depending on Twin Turbo or NA, various trim levels and model years it’s not bad but there is definitely room for improvement. And there is much to remove if you don't mind trashing a lot of nice interior trim. Remember, the Z32 wasn't really designed as a hardcore race car. Fortunately someone has taken the time and the effort to make a more or less complete guide to Z32 weight loss:
Just as FYI: The cars designers made every effort to lighten it even while keeping interior standards up and production costs down. For example aluminum was used extensively (hood, engine mounts, front and rear bumpers, some accessory brackets and all intake castings are aluminum).
It’s all about the corners baby
Now if all we wanted was power that would make us pretty damn pathetic wouldn't it? The Z32 is probably one of the best handling cars under $50,000 that ever came out of the 90s. It lives for the turns. And there is plenty you can do to take it to the next level.
Tires: The most basic and easiest upgrade of the handling system, its also the most effective. Z rated or better tires (Y and W rated) are a must have for any sports car. The downside to high grip rubber is that it does wear faster and the tread designs and materials used for maximum grip usually don't lend themselves to anything but dry pavement too well. Pricing and quality varies wildly here so you're own your own to do some research in this area. As of this writing, there are only a few tires left in the stock rear 245/45/16 size and of those the best is probably the Bridgestone Potenza RE750, so if you’re still rolling stockers, it’s probably the one to choose. I have them and they are a great mix of wet and dry grip, longevity and price.
Urethane bushings: Like just about every other car ever made, the Z32 came with rubber bushings, i.e. the parts that connect suspension pieces. This makes for a nice, smooth ride but the softer the bushings the more movement you get in the suspension system which degrades every aspect of performance. Especially given an older car like the Z32 when normal wear and tear over the years has cracked and split the OEM bushings. This is where urethane comes in. Its essentially hard plastic, though with a little bit of play in it. Without any soft bushings squishing around, the suspension and steering will feel and react much firmer, because it is. This helps you get more from your tires and makes hard steering more predictable. The downside to urethane bushings is that the car will ride much stiffer, you'll feel just about every bump on the road. The Energy Suspension Hyper-Flex master kit comes with just about every bushing on the car and runs a mere $150. They also sell a complete line of bushings so fill out what the Master Kit doesn’t cover. However remember to plan your upgrades as a complete system. If you’re going to get aftermarket tension rods it doesn’t do you any good to get tension rod bushings that you’re not going to use.
Anti-sway bars: Stiffer sway bars won’t flex as much under heavy cornering as the stock hollow bars. The only real problem here is if you go too stiff up front, the car will be harder to turn, it will want to understeer. Too stiff in back and the car can become tail happy and oversteer. However, many aftermarket units are adjustable so you can change the cars setup as needed. These usually run about $250 for front and rear sway bars with bushings. Stillen bars are popular.
- To go with those new sway bars, a nice set of adjustable end links can help you get the most out of them. They can also eliminate preload on the bar or once you get into serious tuning they can add preload to the front or rear.
-This is where suspension balance comes into play. For a car with stock dampers and springs an aftermarket sway bar might have a positive effect. For a car that is outfitted with aftermarket coilovers and uses high spring rates, an aftermarket anti-sway bar might be too stiff even on the softest setting. Do some research and make sure you keep your end purpose for the car in mind when purchasing.
Strut braces: As you replace other pieces with stiffer, upgraded parts, more and more stress is put on the frame and it will begin to flex more because the suspension that was supposed to be flexing has gotten a lot stiffer. Just about any bar will do for the rear so find one that matches your construction and pricing preferences. For the front, a bar specifically designed make room for the stock fuel system is required or else it can rub against one of the fuel hard lines as the engine moves around, pinching off the fuel supply or even causing leaks. Front strut bars can make the car difficult to turn into a corner given other upgrades (like a stiff anti-sway bar), so make sure you have your entire setup in mind when you’re placing orders.
Misc other braces: There is a lot more in the way of bolt on braces. Ladder bars, fender braces, lateral braces, just about everything. With the Z32 these do not really come into play until you get out on to a track but a stiffer chassis can always be appreciated and these upgrades aren't that expensive. If you are handy with a drill and a torch you can make you're own easily enough but for most people, bolt ons will be the way to go.
Springs: Eibach makes a nice set of lowering springs for the Z32. These will drop your car about an inch (.8" to be exact) and make for a stiffer ride with all that comes with. It's a fairly good drop all things concerned. There are other springs out there, so if you’re looking for more drop or don’t like progressive spring rates, try Tein or RSR. However since you are now lower and thus off from the stock camber specs, you'll want to invest in the ready to order camber correction kit from 300 Degree. Between the two expect to spend around $300.
Upgraded shocks: KYB has an affordable set of adjustable shocks for the 300ZX. Four way adjustability upfront and eight way in back. The only downside to this setup is their controls are on the shock meaning you'll be doing so time on your hands and knees to adjust them and you lose out on the mega-super tyte too-close-for-missiles-switching-to-guns in-cockpit electronically controlled stock pieces. I’m serious. That **** is cool. Anyway, expect to pay $350 for the four corner set.
Adjustable suspension pieces bring a lot to the table in regards to tuning. However this is not something that should be attempted ham-handedly. A good understanding of the physics and science behind a suspension system is need or else you’ll probably end up making your car handle worse than stock. Some reading material to get you started:
The primary vendors for suspension pieces in the Z community are SPL and Powertrix.
Upper control arms: Allows you to adjust the camber (vertical inward/outward tilt of the tires) which is handy for the race track or cars that have been lowered. Set of rears runs $250-350 with fronts going for around the same or a bit less. The front control arms should be used with aftermarket tension rods to avoid damage due to caster play.
Tension rods: Allows you to set the caster of the front wheels as well as being an upgrade in strength over the stock unit. However these eliminate the stock bushing at the front, meaning a hard impact like a deep pot hole is transferred directly to the rest of the suspension which can break or bend various expensive things. $150-$300
The next set of parts is for the more track inclined out there, if you have already done the suspension pieces above then chances are your car is at the point where the only place you will be able to test the next series of upgrades is at the track. Now before you go changing a lot of the settings on your suspension make sure you know what you are doing because an ill set up suspension can be dangerous to drive on much less to drive fast on. A good shop that is setup to perform this kind of very precise alignment work is required at this point.
HICAS Eliminators: The HICAS system was designed to increase high speed stability and turn in. It can also create a loose, disconnected feeling for those not used to it. Probably the biggest reason to remove it is that to make the rear wheels turn, the entire rear suspension uses softer rubber bushings than would normally be found on a sports car. There are a few different kits and methods for removing the system depending on whether your car had hydraulic or electric HICAS units. Do you need to delete HICAS? If you don’t already know from personal experience then you’re probably not driving the car at a level high enough for it to matter. An easy way to figure this out is go out and do whatever it is you like doing with the car with HICAS active. Then pull the fuse on the control box and repeat the activity as closely as possible. Having done this I can say that HICAS really does help stability at speed, try performing a quick lane change with and without it to really notice the difference.
Coilovers: At some point in your skid pad endeavors you'll want more control over the suspension, which is where a fully adjustable set of coilovers comes in. These can run $1000-$1500 easily and well over $2500 for the premium parts so this is not for everyone. SPL sells a high quality set of entry level coilovers.
Tie rods: An aftermarket set of tie rods will be a good upgrade in strength over the stock bits and have a greater range of toe in adjustment.
Traction rods: These prevent the rear tires from moving the suspension forward or backward under acceleration or deceleration. The idea here is to reduce flex to keep the tire more stable. HICAS has to go to run these.
Lower control arms: An aftermarket set of lower arms provide the last bit of adjustability and control over the suspension setup. This is really only for dedicated track cars. By the time you’re to this point, you’ve long since needed a professional race shop to set your car up right.
If you got it moving and around the corner, chances are you are going to want to slow it down eventually. The stock Z32 brakes are above average factory pieces. Posting 120 foot 60-0 distances, the 4 piston mono-block calipers provide a hard bite but they have room for improvement as the Z is not a tiny car and the stock 11" rotors are really too small for it. And as a heavier ride, quick heating brake pads and rotors and the resulting brake fade are a problem if you are driving hard for extended periods of time. To address this we go to the following.
Rotors: The basic idea here is to cool the rotors with a directional vane casting on the inside of the rotor to improve air flow through the rotor. This reduces the temperature of the brakes and prevents the loss of hard braking power that occurs when pads and rotors overheat. Aftermarket rotors are often found with aluminum “hats” at the center, good for reducing weight and rotor warping. Specialty Z has a great set of directionally vented, aluminum hat rotors in the stock size. There is a wide variety of drilled, slotted, dimpled and otherwise non-blank face rotors available. There is a lot of information out there (of varying merit) but for the most part the consensus seems to have moved toward a slotted rotor.
-Many aftermarket rotors come plated with zinc or cadmium to prevent rust and corrosion from forming the sections of rotor not in contact with the pad. If you’re chose rotors are not plated as such you can usually find a local place to do them. I would imagine a clean metal surface has a better heat transfer properties than a rusty one and if nothing else it keeps your rotors looking super spiffy.
Upgraded pads: A set of metallic or semi-metallic pads will increase the friction of the pads on the rotor. They will be able to provide more friction at higher temperatures than stock pads. Hawk HPS pads are popular for street applications. WARNING: Some "race only" pads have little to no stopping power until they are hot enough to bed in properly.
Larger rotors: A larger rotor has more mass and can absorb more heat than a smaller rotor. It also has a larger surface area to dissipate that heat. Both of these things reduce brake fade. There are several kits that use larger rotors and the stock front calipers. There is one using the 3000GT rotor, sets from MWS and MATTZ Garage that can fit under the stock wheels using custom rotors, and several that use 350Z track rotors. All use the stock front caliper with a relocation bracket. Only the MWS and MATTZ rotors can fit under stock wheels with no spacers (though if you have the MWS rotors with the aluminum 30mm calipers and the 7 ½” front wheels you’ll need a 5mm spacer, which is included in the kit). Pricing is usually around $500-$700.
Big brake kit: When you finally just need more braking power we turn to larger, more powerful brake calipers. With more and/or larger pistons pushing on each side you get harder and more even braking. There are several kits for the 300ZX. Brembo, Wilwood, Stoptech, Rotora and a few others make oversized front calipers for the 300ZX and Stoptech now even offers a set of rear calipers, something not too commonly seen. However, performance calipers are expensive, running around $2000-$2500 for a front brake kit, usually including the calipers, rotors, pads and steel brake lines. The best price I’ve seen is the Arizona Z Car Wilwood setup with 6 piston calipers and 13” rotors for $1400. For those looking for a cheaper option a set of beefier R34 GT-R Skyline front calipers will bolt up to the 300ZX mounts with only minor drilling and use rotors that are about an inch larger than the stock Z32 pieces. The Skyline brakes can usually be found in the area of $500-$1000. FYI, any of the aforementioned options requires a new set of wheels with the exception of a RMS (http://www.350zbrakes.com/300zxbrakes.htm) modified Wilwood big brake kit. It will fit the stock wheels although there is some trimming of the lower control arms that will need to be done.
- Going your own way: Given that there are many cars out there that have larger factory brakes than the Z32 (Corvette, Mustang Cobra, 350Z etc and so), if you have access to a few bits of machinery you could fab up some brackets and fittings to put a 13" Vette caliper and rotor setup on your Z. Might look odd and you better get it bolted together right but for someone with the skills and tools it’s cheaper than any of the kits.
Steel brake lines: Modern brake systems with vacuum driven boosters can put a lot of pressure into the system, causing the rubber brake hoses to expand, especially on older cars as the rubber is out in the elements getting hot and cold and rain and etc. Braided steel lines use a fine mesh of thin steel wires wrapped around the actual brake hose to control this expansion. The result is a much more direct and firm brake pedal. On cars with ABS (which releases and reapplies brake pressure very quickly as wheels approach lock up) it greatly helps control the stuttering, jarring feed back under hard braking when the ABS system kicks in. FYI, Z32s have ABS. Anyway, a full four corner kit runs around $100.
Master cylinder brace: This mounts up to the side of the engine bay and keeps the firewall from flexing under heavy braking. 300 Degree has an excellent brace for $35. Concept Z has a beef cake brace for $60.
Brake fluid: Last but certainly not least, a good performance brake fluid. Given repeated hard stops from high speeds the brake calipers can get hot enough to boil brake fluid, something that will ruin your day very quickly. A performance fluid like Motul or ATE Super Blue will have a much higher boiling point (500+ degrees), thus preventing said day ruinage. You’ll probably need about a liter and a half to two liters to flush the entire system without having to worry about running out and to have some on hand.
For a mildly modded Z a set of performance pads, steel lines, master cylinder brace and a good brake fluid will be just about all you need. If you want to go further one of the stock caliper-larger rotor kits is a good option. Once you get up to upgrading the turbos and other heavy modifications then looking into a big brake kit is a sound idea.
Manual transmission: The stock 5spd transmission is pretty damn stout and will run upwards of 700rwhp. After that you’re either looking at rebuilding a stock transmission with upgraded parts or finding a custom swap.
Short shifter: Changes the pivot point of the shifter to allow shorter travel. Many people make them, they run anywhere from $100-350. If you’re so inclined (as I am) then you can modify your stock shifter.
Note: If your transmission is going to fail, it's probably going to be one of the syncros. Prolonged power shifting, an improperly adjusted clutch or improper shifting can chew them up. I have actually yet to see a Z trans that has stripped a gear or just totally failed.
The 98+ 5 spd: Even though the Z stopped coming to the US in 96, it was built until 1999 in Japan. In 1998 the transmission received an overhaul, getting stronger syncros among other things. These aren't cheap, expect to pay about $1900.
Automatic transmission: The Z32s auto is tough, the TTs even more so given the extra cooling capacity thrown in. If you plan to head to the drag strip, you'll want that automatic for its quick and consistent shifts. Road racing or drifting probably not but for a street car it does taken away that stiff ass clutch that you have to shove down every time you shift (yeah, the 5spd is fun but with a hard clutch it gets old quick).
Automatic line controller: The stock computer that controls your automatic transmission is set to provide a constant amount of pressure in the system. As you begin to shift faster under hard acceleration the pressure can begin to drop, resulting in slower, sloppier shifts. An ALC is basically a digital pressure sensor that will signal the pump to step up output when the pressure begins to drop. As far as I know HKS is the only manufacturer with a plug and play unit for the Z32 automatic transmission and their piece retails for about $300.
Flex plate: This upgrade is for strength, as stock the flex plate weighs only a few pounds and so its not as if you could improve upon it that much. But as there is little metal to a stock flex plate, it can literally be ripped to pieces by a high powered motor. Specialty Z makes the only one I’ve seen on the market. $475.
Built to the nutz automatic transmission: The stock 300ZX automatic is pretty damn tough. But like all things, at some point (generally considered to be about 500 rwhp depending on who you're talking to), its needs more beefing. A fully built transmission is tweaked in a number of ways, usually replacement of the clutch discs for higher capacity pieces, upgraded torque converter, altered/upgraded fluid lines and servos plus a few other things. After all this, you're going to get lightning quick, predictable shifts. If you want to drag, this is the way to go. There are a few outfits doing this work and prices range from $1500 to $3000. From what I’ve seen, Specialty Z probably has the most capable modified stock transmission, which they run in their 9 second Z.
TH400: BDE has engineered a TH400 swap for the Z, a transmission that brings a wide variety of aftermarket support and a reputation for being near impossible to break. If you’re going with huge power and like drag racing, this is definitely something to look into.
And coming out the back:
The stock drive shaft will handle just about anything you can throw at it (700+rwhp). But given a worn, out of balance stock drive shaft that would cost $250 to rebuild or a 2+2 TT conversion that requires a custom driveshaft or just wanting to drop some weight from the drive train, you can get a one piece made up for a few hundred dollars at just about any local drive train shop. There are also many companies making one piece drive shafts as well so shop around for preferred materials and construction.
Some general Z advice
Item 1: BUY A FACTORY SERVICE MANUAL!
Item 2: LABEL EVERYTHING!
Item 3: Understand this about the 300ZX. It’s not the easiest car to work on. Everything under the hood is packed against everything else and much work requires removal of surrounding unrelated parts. But the way the Z is setup, plumbed and wired in the Z32 chassis is fairly simple and makes a decent amount of sense. The amount of wiring and tubes/hoses is actually fairly limited, it’s a pretty clean and concise engine bay really. The Nissan engineers did a hell of a job making the car as easy to work on as possible, given the amount of stuff they had to pack into a compact space. But then again I've been accused of being the optimistic type.
About this FAQ
This is merely the end result of having to answer the same “What should I do to my car next?” post once or twice a week here on the local Z car board. It kind of grew from there but I’ve tried to keep it true to its original purpose. That is: to be a very general bit of information about what’s available for the Z32, common pitfalls and combinations that others have had luck with. I’m by no means an expert on anything listed in here though I’ve done quite a bit of research into the matter and have done an engine build, suspension and brake work and all manner of other things to my Z so I’d like to think I’m a decent fit for authoring this piece. Any questions, additions, comments, concerns, gripes, insults or contact simply categorized as “Other” can be directed to my automotiveforums.com PM box or drop me a line using the email associated with the same. All input is appreciated. If you wish to post this on another board I ask only that you link to it rather than copy and paste.
Props to da homies:
Just about everyone on Twinturbo.net.
The regular group of bastards on the Past Z forum.
All of the shop owners, store managers and parts makers that have taken time out to educate a fellow Z owner.