[dustinr]

Anyone add to this if you feel I left something out (which I'm sure I have).
After buying my '05 Sti I've been in research mode trying to figure out some good, reliable, hopefully covered under warranty, performance mods that have some descent gains. The conundrums I've found is A.) problem free operation and B.) warranty.

I've read tons of oppinions, tests, and problem faq's and I've spoken with my dealer and some local tuners about warranty stuff. Warranty is the getter for a lot of people; if you're not worried about warranty then your options definitely open up and your performance gains are "skies the limit." but even so there is a definite order to things...(ie you don't want to run a custom mapped and boosted ECU program without first swapping your fuel pump.)

But since I'm only concerned with mods that can be done somewhat stealthly for warranty concerns, there are limits.

1st one is the intake silencer; can be taken out and replaced with elbow without any side effects beside better sound and probably a small increase in air flow.

2nd. probably a good idea to swap out fuel pumps to the + 1 bar Walbro pump; this will let your injectors work a little less hard.

3rd. The stock turbo needs to have the wastegate hole ported so that it can physically dump more pressure.

4th install a turbo back exhaust system but not untill you've done step # 3 or you will get boost creep...period.

5th. In my oppinion the Cobb AP is the neatest and stealthiest way to make changes to the ECU maps without voiding your warranty (you can always set it back to OEM map and unplug it)

This should net a pretty descent gain without making it blatantly obvious to a dealer that you've modded the car. A turbo back exhaust shouldn't void the warranty unless your dealer is very anal (my dealer is pretty anal and they even said an exhaust won't void the warranty.)

So... this is just what I've managed to learn thus far, please feel free to add any recomendations or comments. I would like to start a good thread for guys like me that are interested in modding within the limits I set above. I've noticed a bunch of people just start modding without having done any research and then they have to diagnose problems that were caused because they didn't do something first-off that they should have to avoid such problems...(ie installing a turbo back exhaust without having the turbo ported).

[Guru]

Looking good although skip the fuel pump. Complete waste of money for you. Be prepared to get smoked by just about every other STi. Most guys with STi's couldn't care less about warranty and thus are looking for large HP numbers.

[njmf]

I can't seem to find any more material on removing the intake silencer, is there a post or site that has directions on how to do this free mod? Also what will I need to complete it and will I lose power from it or just increase the sound? Thanks

[Boxer]

Make an engine management choice first then add bolt ons with tuning. Don't forget about the suspension because more hp won't get you through turns faster.

My $.02

[staticx313]

Originally Posted by Boxer

Make an engine management choice first then add bolt ons with tuning. Don't forget about the suspension because more hp won't get you through turns faster.

My $.02

EXACTLY... GET engine management. I did every bolt on out there and have greatly regretted it. I sold every part and am buying an ecu first and am now restarting... DO IT RIGHT THE FIRST TIME. Trust me, it saves money and stops a lot of problems. Not to mention that a UTEC upgrade yields the MOST hp /tq increase out of any mod out there anyways (other then a turbo of course). So why not do it? Good luck!

Robert~

[STi_high]

my dealer told me that if i get the wastgate ported, that my warrenty would be out the window......i think its time to find a new dealer.

[BongMonster]

pardon my ignorance...

what is

"3rd. The stock turbo needs to have the wastegate hole ported so that it can physically dump more pressure."

Specifically porting the wastegate hole, I'm not sure what that is.

thanx in advance for any info

[staticx313]

The wastegate hole is what is used in the turbo to release excess exhaust gasses (to keep your car from spinning the turbo to XXpsi). When you add afree flow TBE or something of that nature... you begin to overflow the wastegate to where it cannot release the exhaust gas out fast enough. This causes boost creep (to where it will hit 19psi or so)... which is BAD for an untuned engine. Fuel cut among other things will occur.

Robert~

[criz]

can the dealer tell if the wastegate is ported?

also, I thought a turbo back would void the warranty...hmmm... i'm going to have to talk to mine :wink:

[salisburyv]

just about any mod you do the dealer is going to tell you your warranty is void....i've brought up the moasis act tol them and they laughed at me...i am looking for a new dealer...i need a new front o2 sensor...they say cause of my mods it failed....dealers suck! but anyway...i dont regret any of the "bolt on" mods i've done....i drive a rocket even more so then when i bought it...dyno numbers dont lie...with just bolt ons...312 awhp/323awtq...i'm gonna stick with that...for me engine management, while giving alot of flexability and added horsepower...will cost me another clutch...seen it happen...and maybe an axel or two, maybe a diff as well....thats what i've seen...check my site for my mod list...but find a mod friendly dealer...cause the ones around here, while they love what i've done to the car, they wont touch it, and now that i'm thinkin about it...i dont want them to either!!!

[dustinr]

My reply to the posts above:
A dealer would have a hard time recognizing a ported waste gate unless they're extremely observant. The TBE shouldn't void the warranty unless you buy a catless TBE, then I can see them noticing, but to blame the exhaust for a engine or tranny problem is pretty reaching unless of course you don't port the Turbo and you end up harming it somehow. To say that STi owners aren't concerned with warranty is a pretty broad generalization; I for one am concerned. The reason I chose the Cobb over the Utec is due to it's simplicity. The UTEC requires a dyno to get it set up correctly right? And although it's a plug-'n play device doesn't it wire in to the harness next to the stock ECU? The Cobb just plugs in under the steering wheel. The silencer on the intake is just that...a silencer, so you remove the silencer and replace it with a simple plastic elbow, there a couple different vendors selling them; I've even seen them on Ebay. Suspension mods are a personal thing, If there's something about the handling that you don't like then make a change, other than that just because there are aftermarket suspension components available doesn't mean they're all better... IE lighter wheels make a bigger difference than pink springs.

[Boxer]

Dude, the dealer will likely void your warranty with a TBE(catted or not) because their thinking is it causes boost creep without turbo porting, regardless whether it does so or not. This alters the stock configuration which only they're responsible for under the warranty agreement. Sure, you can go to small claims court, or whatever, to try to prove that the TBE didn't cause the warranty problem but it's a big headache.

As far as the suspension goes, sure, to each his/her own but most of us have problems with the compromised US market STi suspension. Most people who've switched to other brake pads, brake fluid, pink springs,and hardened strut tops are quite satisfied with the improvement over the some times squishy originals.

[dustinr]

Why do you say "compromised US market STi suspension?"

[Boxer]

Originally Posted by dustinr

Why do you say "compromised US market STi suspension?"

See, we Americans, according to Subaru, don't like things too rough. The US STi suspension has different springs than the European/ Japanese versions. They're softer and, therefore, lead to more body roll, squat, etc.. In addition, I believe the overseas versions have stiffer suspension bushings as well.

Also, the seats are configured for larger rear ends(damn stereotypers!) and I would gladly trade them for the JDM STi Recaros.

[dustinr]

Now it makes sense! The shocks do seem to be valved a little funky for the springs that are on it, I notice it at high speeds going over bumps. How much do the pink STI springs lower the car? And do you need to change the camber angle due to the lowering effect?