Exhaust questions

[kyle5050]

I am currently turboing my 92 na talon. I have a greddy fm intercooler, b16g turbo, greddy piping, greddy blowoff valve, and all other parts off a stock tsi. My question is, for running around 8-10 psi, what kind of exhaust and downpipe should I get? Not talking brands, but pipe sizes. I've heard people say only go with 3 inch if your running turbo. Is that true? Or can I use a 2.5 inch setup?

 

[doug]

Originally posted by kyle5050
I've heard people say only go with 3 inch if your running turbo. Is that true?

No.

Originally posted by kyle5050
Or can I use a 2.5 inch setup?

Yes.

 

[AWDkitkat]

Might as well get a 3 inch. the day you upgrade to a 3 inch exhaust you will regret not getting a 3 inch dp .... I am

 

[doug]

Why?

 

[AWDkitkat]

because ive out gown my 2.5 exhaust and now have to upgrade my dp along with it.
If i had a 3 to begin with i would have some extra cash.
A 3inch dp is fine on a 2.5 exhaust so why not do it right the first time.

 

[doug]

How do you know you've outgrown your 2.5" exhaust? I'm not trying to start an argument or dispute what you're saying, just wondering and trying to learn... I appreciate any insight you have.

 

[AWDkitkat]

Just from exp ive seen more power to be had out of a 3 inch and my setup. theres no real way to tell unless you just go by mods or dyno one on your car before purchas (good luck with all that) .16g and smaller wouldn't see much gain but it also wouldn't hurt.
Basically, why shoot yourself in the foot if you have plans for the future?

 

[jim97gst]

theres no real way to tell unless you just go by mods or dyno one on your car before purchas

You could do a 1/4 mile run with you 2.5" exhaust, then disconnect the exhaust from the downpipe back, insert earplugs, and do another 1/4 mile run and compare. Not terribly scientific and kind of a pain in the ass, but it may show you that you don't need to spend all that money on a new exhaust.

I got a 3" exhaust because I wanted to run a cat and wanted to try and compensate for that loss. I also heard that I should see slightly quicker spool-up. I mostly autocross so that is very important to me.

 

[TellschAWD]

Originally posted by AWDkitkat
Might as well get a 3 inch. the day you upgrade to a 3 inch exhaust you will regret not getting a 3 inch dp .... I am

Remember he is only running 8-10psi on a smaller turbo (assuming smaller) in a 2.0L engine.

Mandrel bent 2.5" is fine

 

[AWDkitkat]

Originally posted by AWDkitkat
16g and smaller wouldn't see much gain but it also wouldn't hurt.
Basically, why shoot yourself in the foot if you have plans for the future?

 

[kyle5050]

I think I am going to get the 3 in. turbo back rnr racing exhaust. I do have plans for the future awdkitkat, next year when I get a new car I am going to make my talon a track only car and not having to replace exhaust would be a good thing. Even if it won't do much, why hamper performance even just a little bit when you can help it a little bit?? I am getting all my parts through a local shop, and I cannot find the part number on the 3 in. turbo back for my car. Is rnr a small operation and do I need to buy straight from them? If not does anybody have the part number on it? Thanks.

 

[jim97gst]

They don't have part numbers. They only sell out of their shop. Just email them and tell them what you want. I recommend getting the O2 eliminator option. Then you don't have to mess around with porting your O2 sensor housing and you'll have true 3" from the turbo back.