QUOTE (d-monic951 @ May 17 2009, 04:31 PM)

what are some quick and cheep thing to do to a 94 3000gt NA to gain hp
i know intake and xast
but any other miner thing that u can do to up the hp
thanks
i know this is for the sl model, but i found a great site that has some good info for the tt tuner. this is from the 3SI.org website, so im not plagiarizing lol and all the numbers above the stages are approximate HP gains
Staged Upgrades: 3000GT VR-4 and Stealth TT
Everyone has different tastes and preferences. This list is by no means a definative source. The greatest caveat is that evry car is different and results will vary. Also some of the parts mentioned may be for off-raod use only in your state.This is only a general guideline. Some components mentioned here may be substituted or left off depending on personal preference and perfomance interests.
Aproximate HP Gains
Stage 1: Tune Up and Performance Prep
The first thing you want to do before adding more power is to go to a reputable shop that can give you a complete tune-up. Install a set of Magnecor KV85 8.5mm plug wires and a nice set of NGK plugs. Also make sure that your stock fuel injectors are cleaned and balanced. If your car is approaching 60K miles, please have your timing belt replaced if you haven't already done so. With these done, you are now on your way to making more power, safely.
NA
Stage 2: Intake
What you want to do here is to improve the flow of air through the engine. The stock airbox is very restrictive. Replacing that with a open element intake like the K&N or HKS Power Flow helps the engine breath better by allowing more air in to the engine.
6-8
Stage 3: Exhaust
Likewise the exhaust will also improve the flow of air through the engine. The stock exhaust from Mitsubishi uses small piping that are bent in a lot of places, restricting flow. It is recommend you go with a larger diameter and mandrel bent exhaust.
8-12
Stage 4: Boost Controller and Boost Gauge
Once you have opened up the air flow with the intake and exhaust, it is now time to turn up the boost! By installing a boost controller, you can take advantage of what you've done in stages 1 and 2. This also allows you to put the factory turbo to full use. The stock boost on the '91-'93 cars were set at around 9 psi, and the '94 and newer cars are factory set at 12 psi. With a boost controller, you can now safely turn the boost up to 14 psi on both generation models. At this time, it is extremely important to install a aftermarket boost gauge. The stock gauge is highly inaccurate! The boost gauge is both a safety precaution and a great diagnostic tool. This allows you to make sure that your car is not over-boosting or under-boosting. Also do not boost past 14psi with stock fuel injectors. Even if everything "feels" ok.
You will knock and approach fuel cut. Fuel cut has a very high percentage of breaking a piston and or a valve. After 14lbs of boost a stock turbo system is just dumping in a lot of hot air. Resist the urge to turn it up. Do not overboost!
30-50
Stage 5: High-Flow Cat
Installing a street-legal high flow cat is the next step.
15
Stage 6: Downpipe
After you turn up the boost, it is now time to free up the exhaust some more. The downpipes that comes from the factory is (what else?) very restrictive, not to mention heavy. By installing an aftermarket downpipe, you will notice a weight savings of approximately 10 pounds.
15
Going past stage 6? Now your starting to get serious!
Consult with your favorite 3S tuner for combinations, brands, etc. It is also important that you have moved up to stage 4 on the performance chart by this time.
Stage 7 upgrades have been considered best to get all at the same time.
Stage 7.1: Fuel Pump
You will need a unit capable of much greater flow. Yes your gas mileage will start to drop with Stage 7.
25-35+
Stage 7.2: Fuel Injectors
Most people move up to the 550cc flavor. These are a large move over the stock 360cc injectors. Some people will use the 450cc injectors out of the turbo eclipses and some people go all the way up to the 720cc models for real tranny busting power.
Stage 7.3: Air/Fuel ratio controller
There are several to choose from. This will control the extra fuel you will be dumping in. Also getting a Air/ Fuel ratio gauge is a good idea. There are units that range from $300 to $1,500. So be sure to research the one that will perform to the level you will need.
Stage 8: Larger Turbos
Now after stage 7 you are ready for a turbo upgrade. The two most common upgrades are to the 13g and the 15g turbos. These two units just bolt on and will provide a large power gain.
13g - 40
15g - 80
Stage 9: Intercoolers
Now after your turbo upgrade. You need to get the air charge temperature down. The amount of power is proportionate to the intercooler size and turbo size.
20-40+
Stage 10: Ingnition
You most likely will need to supply a hotter spark to ignite the increased fuel and air mix.
2-4
Stage 11: Underdrive Pulley and Aluminum Flywheel
These are two controversial upgrades. Most tuners recommend you balance your crank in order to safely and effectively use these two mods. On the other hand several guys have put them on without balancing their engine and have had no problems. Just be sure to research this one for yourself.
15-20
Going past stage 11? Now your obsessed!
Consult with your favorite 3S tuner for combinations, brands, etc. It is also important that you have moved up to stage 8 on the performance chart by this time.
Stage 12: Port heads, intake, and exhaust manifolds.
The Factory intake and headsare actaully very nice out of the factory. They could use some improvement when you to want to build more than 550 or so horse power. The stock exhaust manifolds could use some work at just about any stage.
10-40
Stage 13: Forged Pistons and Rods
Forged Pistons will allow you to safely run much higher boost. Plus while tuning and you hit detonation you piston will have a much higher chance of not sustaining damage.
Forged Rods will let you really pound on the crankshart with out warping, bending or breaking. At lease compared to the stock rods.
Allows higher boost
Stage 14: Heat Treatments
You can have your Pistons, Valves, Turbos, Exhaust pipes all coated wit a space age ceramic coating. This coating will reduce air flow temps. Lower temps allows for more boost!
Allows higher boost