Well first off i wanted to say that i'm new to subarus and to this forum. my very good friend dmitriy got me to absolutly love these cars. he used to have a slightly moded 02 wrx and he now got a 04 wrx that's slightly moded as well.

i'm working two jobs and saving up enough money in order to buy a 04 or 05 sti and do some slight mods to it. below is a list of the parts that i want to get and install on the sti... so will someone do me a huge favor and tell me where this will put me, power wise...

perrin cold air intake
perrin downpipe with high flow cat
perrin uppipe
hks hi power 3" exhaust
boost controller (planning to dd at 10 psi and sometimes run 17 psi.
hks ssqv bov

also if there are any other upgrades that i can do without taking out or opening up a motor, please let me know. thanks.

-Acet

 

Welcome to I-club.

 

Don't bother with...

uppipe (stock unit flows plenty)
boost controller (not recomended; old school method)
bov (not necesary for boost below 20psi; will cause idle problems)

The above are pretty worthless mods on a near stock STI. Save your money for an ECU reflash.


Good luck!

 

Thanks!

So keep boost to stock?

And

What exactly is a ECU reflash and how much does it cost?

Thanks.
-acet

 

a ECU reflash basically remaps your ECU to add power and better drivability. normally people go with ECUTEK or Cobb Accessport and take it to a tuner. someone like Ed at Eq tuning or Mike at GST have very good reputations.

I personally Had my car tuned at EIP Racing in San Jose by Paul. He got my car to 248WHP and 273WTQ on a stock 04 STi on 91octane. this was a somewhat aggressive tune so with your mods and a good tune from a reputable tuner look for numbers a little higher than these.


Oh and SuperglueWRX is Right, those mods are not needed for a lightely modded car. I'd say you wont even need the cold air intake until you reach upwards of 300WHP

 

thanks for clearing that up for me.

ok since you say that those are pretty useless upgrades until i get to 300 whp, what mods can i do, that dont require me to open up the motor, that will increase the horse power?

 

Turboback exhaust(downpipe, catback), Engine managment(Accessport), you can also look into getting some headers, they will help increase torque and help with top end acceleration. If you are going for intake the Cobb short ram or the SPT intake seem to do quite well and don't effect MAF readings(intakes are usually a negative thing when it comes to Subies, the stock airbox/intake sysytem can handle up to 400hp). Thats pretty much it power wise until you go for a bigger turbo setup. Ever thought about suspension? Start with some springs/coilovers and at least get a rear sway bar, the difference is night and day.

 

Ok and also i have a question about the intakes on the subarus. i helped my friend install his aem cold air intake on his 2002 and we had to take off the fender. When i look at some pics, however, i see that a lot of people have the short ram intake along with the flastic piece in the fender. whats the difference and would a brand new, i.e. aem, injen, perrin, cobb COLD air intakes effect the MAF readings?

And yes i thought of doing the suspension as well. i'm thinking either tien coilovers or cusco. the sway bars i'm getting as well but thats all AFTER i get the car

BTW what does a stage 2 or stage 3 mean? in the section about what car you drive?

 

I wouldn't sweat the cold air intake too much. As far as I know, they only provide minimal gains on STIs and are less than desirable on 02-05 WRX models.

Stages are just how aftermarket companies package their parts. Stage 1, 2, 3, 4 are most commonly refering to Cobb Tuning parts. Here's the way it was explained to me:

Stage 1: ECU reflash (you need to buy a Cobb AccessPort for this $600-$700)

Stage 2: ECU reflash + Turboback exhaust (I recommend you buy used exhaust parts to save a few hundred dollars)

Stage 2.5: That's a stage two with a few small upgrades such as up pipe, larger intercooler, headers, and usually a tune; the definition is not exact)

Stage 3-4: Also not exact, but normally involve an upgraded turbo

Don't let the price of the AccessPort deter you. It allows for almost infinite tuning for your ECU if you decide you want more boost than the off-the-shelf map that comes pre-installed or if you want a larger turbo.

For a similar price, you can get equal tuning flexibility with the ECUTEK. You might want to look at the vendors section of the forum to find companies that sell and tune these products.

With some good tuning and minimal bolt ons, some tuners have gotten low 12 second quarter miles on the STI with the stock turbo on 91 octane. A good tune can go a long way.

Feel free to ask any more questions, most of us are here to help.

 

ok so here I come with the questions...

As far as i know, the 2 wheel drive turbo cars dont have headers, they have exhaust manifold. Is 4 wheel drive different? I am unfamiliar with the 4 wheel drive cars.

Also I know about tuning. Is Cobb ECU upgrade kind of like AEM EMS? Which one would be better?

And are the subarus "fuel system upgrade" friendly? As far as fuel pump, injectors, fpr, fuel rail?

Is there a shop in Atlanta area that specializes in subarus? i learned not to trust some places...

 

As far as i know, the 2 wheel drive turbo cars dont have headers, they have exhaust manifold. Is 4 wheel drive different? I am unfamiliar with the 4 wheel drive cars.
Headers have nothing to do with the drive train. "Turbo manifold" and "header" are sometimes used interchangeably. In a turbocharged vehicle's case, the section of pipe that connects the exhaust manifold to the turbo is the the "turbo manifold" (or "header" as some people prefer to call it).

Also I know about tuning. Is Cobb ECU upgrade kind of like AEM EMS? Which one would be better?
The AEM unit you mentioned is a stand alone unit. The Cobb Accessport is a handheld unit that talks to your ECU via the diagnostic port. It can be used to remap the ECU and read problem codes. The newer version has a few other features I'm not aware of, but I'm sure they aren't very important.

And are the subarus "fuel system upgrade" friendly? As far as fuel pump, injectors, fpr, fuel rail?
If you plan on using a larger turbo then you are going to need to upgrade the fuel system. If you plan on using a larger turbo like a TD05-18G, you'll need to upgrade the fuel pump, injectors, as well as have someone professionally tune the new set up.

Is there a shop in Atlanta area that specializes in subarus? i learned not to trust some places?
I'm sure there's somewhere within a few hours drive

 

Ah ok now I see what they mean.

I have also heard this rumor that once you begin to heavily modify the STI's, they begin to break a lot. Is this true or not?

Also what are some key things to check when shopping for a STI. Is there anything that I need to pay a lot of attention to?

Also the STI is going to be my daily driver for the most part. If I do some ECU, exhaust, intake, turbo manifold, and other similar upgrades, will the car still be reliable.

What are some known issues with the 04-05 STI's? (for example I know that on older MR2's, 2nd gear syncros go out a lot..)

 

Just my 2 cents; there are a lot of other people on here that know way more than I do so I'm not a person you should concidered professionaly educated.
I have a 2006 wrx with sway bars, springs, new wheels and tires and I use it as my daily driver. I am planing on getting a down pipe and a cat back or axel back then a Cobb Access Port V2.
As a daily driver I have no issues and i've come across nothing but positive remarks about getting all these mods done.
A long time friend of mine has a 2006 wrx STI; his mods are a little different and might fit your questions better. Kartboy short shifter, sway bars, spings, exhaust and is looking into getting an AP (accessport). He uses his car as a daily driver and drive about 15 miles to and from work and then around town when we go out.
Some people have said that our tranny's are weak but from what I've heard our tranny's are fine if you daily drive it. If you upgrade the turbo and track your car or drag your car then any stock tranny can experience problems. I've heard tranny mounts and engine mounts help for an everyday situation.
If you are looking for a daily driver I (unprofessional opinion) recommend getting exhaust and suspension done to make a good performance car that is all around realible.
I hope this wasn't too long and wasn't full of nonesense I'm just putting in my 2 cents.

 

okay here we go:

1. A lot of issues can come down to a car breaking down, but as far as modding their are STi's out there with 500WHP on the Stock Block and Transmission. granted most if not all are NOT daily driven. the type of driver can also play a role, if you constantly drive you car hard, then yes your car will break down faster.

2. Shopping for a STi, look for the main mechanical things. check the tire wear to see if its even, look under the car for any damage or welds, Check the trunk, the hood, and the interior. It would be best to take someone with you who is knowledgable about cars to help you out in not getting the slip.

3. Yes, If you take care of it. Those are pretty simple mods so you wont most likely have issues. Remember to check the oil every other week or so cuz turbo cars do tend to burn some oil. My friend is running a 20G turbo in his car that is making about 320WHP right now in his 06, this car is daily driven and he has had no issues with it as of now.


oh and as far as headers, if you arent going to buy equal length headers, then i would suggest just porting, polishing, and jet coating your stock ones. It does the same job as a aftermarket header but for a little cheaper. just my .02 cents

hope this helped a bit.

 

thanks for your input. i will most deff keep this in mind.

thanks for taking your time and responding. i will deff take someone who knows subarus inside and out to help me pick the 'perfect' one.

so as i can assume from all the information that i have received, light mods such as ecu, exhaust, coilovers, sway bars shouldn't give me any problems.

thanks a lot for all the responses.