8 replies to this topic

[sayre]

I have a 2002 wrx hatch still under warranty from Subaru. I'm looking for a bit more power, and am wondering the most cost efficient way to go about it, that won't affect the new car warranty. Powerchip maybe?

[Setright]

Well, it may just be my opinion but:

Chip tuning won't give you very much extra power. If it does, your reliability is going to suffer. Most chips tend to allow higher boost, which means more petrol and therefore more power. Disregarding the added stress of extra boost, consider the need for extra fuel. Chips often just prolong the injector pulse, moving it forward in time and spraying before the intake valve is opening, which negates one of the main advantages of fuel injection.

To do it right you need to replace the injector nozzles and usually the injector itself and the pump. Why? Because the nozzles in the engine are designed to deliver fuel at the "normal" rate.


I do condone getting someone to customize a chip for your exact engine. The OE chip is programmed for an average engine of that particular type. Specific programming will enhance throttle response and give much smoother running. Power and economy gains will be part of that package, but don't expect more than a few horses.


Sorry for being such a wet nappy

[wrxsubaru]

Originally posted by Setright
[B]Well, it may just be my opinion but:

Chip tuning won't give you very much extra power. If it does, your reliability is going to suffer. Most chips tend to allow higher boost, which means more petrol and therefore more power.

Running more boost is really the only way to gain a substaintial amount of power, if you get a better flowing exhust, Down pipe, up pipe, and the rest you would gain some power, and you should have less turbo lag, and a better throtel response, but it would void your warenty like almost all performace upgraes.

The stock WRX should be able to handle a couple more pounds of boost shouldent it?

[torxxx]

I wouldnt try getting more power out of that WRX until you change transmissions in it.. The reg. WRX has a piece of **** transmission that IS NOT covered in the warranty (spent an hour last weekend at the soob dealer discussing it with the dealer)

If you want to take that WRX and make it fast, get ahold of a STi transmission.. They are the bulletproof ones.
Then get do a ECM/Fuel delivery system upgrade, 2 stage turbo,
new pipes and hook a cheap NOS setup to it..

[alias20035]

I would avoid powerchipping any Subaru. Subarus tend to run very badly with them, and the power gains are simply not worth it.

Your best bang for the buck solution is to simply get the turbo spooling up quicker. Just getting the turbo to spool up quicker will make the car feel like it has a lot more power even though it does not.

MRT Performance of Australia has some really good exhaust products. Their front pipe with their redesigned turbo inlet is superb at improving spool up! Go to their site, register and get their catalog (as a PDF). MRT parts are available at many dealers in North America, and most will stock the turbo inlet for your WRX.

After the exhaust system, I would also consider a larger and more freely flowing intercooler, and perhaps an intake.

Only once the exhaust and intercooler have been taken car off would I move on to change things like the blow off valve, waste gate, fuel controller, etc.

As torxxx mentioned, if you want to get better than 250hp you will need to change the transmission, the stock WRX transmission is just barely strong enough for 227hp, and leaves little headroom for power enhancements.

By reducing the turbo spool up time you will get much better performance without additional power, so no other modifications such as fuel controller and transmission will be required.

[1 Lucky Texan]

Those MRT guys have some cool stuff.
You could investigate real dyno tuning and maybe some (toluene) higher octane gas/more boost.
Advice about the tranny crops up all over - do not try any stunts/'launch techniques'.

search around over at www.nasioc.com and www.i-club.com

[slideways]

I have to disagree. Those motor and tranny setups are regularly sold stock in Japan at about 280 hp, on the same turbo. Due to our emissions laws, especially in California, the WRX is fitted with three catalitic converters. The close-coupled cat on the up-pipe is of most concern since it robs the turbo of much needed energy, and could dissolve the turbo if a peice went into the turbo.

If you want more power but do not want to get hog wild, I feel that Vishnu's Stage Zero is the best bet. It will give you about 40 hp at the wheels which is huge. The kit includes a piggy-back ecu chip (I believe it is a Unichip, but Vishnu tunes it), catless up-pipe, new crank pully, belts and plugs. At about $1200, or last I checked, that is a bargain.

I also have to disagree about the transmission. Many people have no problems running 250 hp at the wheels with the transmission. It is all in how you drive it. Dropping the clutch at five grand at the drag strip is definatley misuse of the car. With the traction of four wheels, it is rediculous to expect any transmission to hold up to that abuse. Many people whine about it becasue that is what they are doing to their machines and breaking gears. This just is not an issue in two wheel drive cars. A dealor can only deny you warranty on the tranny if its failure is a direct result of your modifications or misuse. Otherwise it is unlawful for them to do so. Same goes for the rest of your modifications.

About ten hp can be gained from the exhaust, depending if you want to go catless and how much noise you can stand.

Sport Compact Car had just under 250 hp at the wheels with the stock intercooler. They upgraded to an APS TMIC and found little or no gains in real world testing.

Just going off of what I read.

[torxxx]

slidesideways -

From what I said about the tranny's is coming straight from the dealer who's had about a dozen WRx's brought back with blown tranny's.

I realize the Jap version of the WRX has more power, but its most likely they are using diffferent kinds if hardened metals in the tranny.

About dealers not covering the warrenty, yeah well it doesnt neccesarily work that way.. They can void warrenty on anything they want to. Have you ever power shifted a WRX? The tires DO NOT break loose. all they do is grip.
Misuse would be getting the tires to spin (breakloose) This is damn near impossible in a stock WRX.

[wrxsubaru]

The stock WRX 5spd arnt crap there acully pretty good. If you look the people who break there wrx trannie 95% of the time are people who beat the crap out of it, flooring while shifting, not using the clutch, stuff that puts alot more stress on it than there shoiuld be since you can't break the tires loose all the stress of flooring while shifting, shifting with out the clutch gets put put on the trannie. I heard of people with huge amounts of power in the stock 5spd, and they dont break if you dont drop the clutch or "power shift" as some people put it. Therte not the strongest tranies 6spds are stronger, but the 5spds are not weak.