I didnt catch the writers name but this is a must read. I pasted a portion of the material incase the link ever went down.
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.
http://www.nmimports.com/index.php?opti ... d=1:latest
Destroying the World in Your Z32: Tuning Tips
*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:
http://www.phatg20.net/modules.php?name ... oad&cid=67
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?f ... 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: Jim Wolf, AshSpec, Ztuner, Z from Japan and a few other shops. 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 a**, 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-f***-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.
For more advanced tuning, follow the link to read the rest.
http://www.nmimports.com/index.php?opti ... d=1:latest
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.
Thanks to SuparexTT @ tt.net for posting it
Request to have this pinned!