I want to change out my straight pipes (2.5" true dual) to the GReddy EVO TT.

Will changing out the exhaust mess up my current tune? I'm not changing test pipes or anything else. My current exhaust is just poor quality, doesn't fit perfect, etc, etc.

And the EVO TT looks so cool.

I have APS TT, F-Con VPro, GTM Flash, pushing 437.8whp and 416wtq @ 9psi.

Thanks!

 

no one can really give you an answer for this till you put the car on the dyno and see if there is any changes in the A/F ratio..


the way I see it, EVO TT is 2.75", thats bigger than your current exhaust, so I would say it'll slighty mess your current tune since you're reducing back pressure.

 

It might need a touch-up, but it might be just fine. As Dubai suggested, you might want to test it on the dyno after the exhaust install. The most important thing, is to make sure your boost levels remain constant. Less back pressure usually results in higher boost pressure, so watch out for that.

 

If your just going for the cool factor, going with the EVO TT is ok. If you want some more power go with the APS 3.5 test pipes along with the EVO TT. I switched out my APS 2.5 and Injen exhaust for the APS 3.5 and EVO TT and was very happy with my gains. I stretched the bottleneck(2.75") in the EVO TT to match up with the 3.5 test pipes and it only took like 5 minutes.
What size test pipes are you using now? And yes a little tweak in the tune won't hurt.

 

Yeah but Sam from GTM is a thousand miles away.

Not really the coolness factor, my current exhaust was made by Scott Performance is is really sketched as far as quality and construction goes. It WORKS, and it WORKS VERY WELL. However, it is a P.O.S. I hope that makes sense.

I'm looking for a good exhaust that's gonna mount properly, etc.

How much does it usually cost to get a custom exhaust done? I heard only a few hundred dollars. I'm thinking of making another, more QUALITY 2.5" dual and buying my own mufflers (carbon).

 

get 3" exhaust and aam 3" downpipes / wastegate dumps. itll let alot more flow, and the wastegate dumps will put less pressure on the turbo. plus itll sound cooler

im having a shop make mine. they do great work, plus i kinda kow them. so im geting everything (hks carbont ti mufflers, wastegate dumps, and full 3" downpipes and piping) for a little less than 1k

 

You won't need a tune. And the hp difference will be marginal.

 

Go with the APS 3.5 Test Pipe and the APS 3.0 exhaust.....best exhaust in my opinion !

 

May I ask what gains did you achieve.