Anyone know Stock downpipe diameter?

[Xkrfiesta]

I know it's 3" up to the flexible part, but what is It after that. The Cobb is 2.5, so stock must be less. If so, that is the restriction in exhaust and anything larger for a cat back won't flow more unless you swap dp, correct?

 

[mattyboh]

I know it's 3" up to the flexible part, but what is It after that. The Cobb is 2.5, so stock must be less. If so, that is the restriction in exhaust and anything larger for a cat back won't flow more unless you swap dp, correct?

I want to say that flex section has an ID of ~2". It opens up a little bit at the flange.

 

[Xkrfiesta]

If that is the case, then really is there any benefit if you have the stock downpipe of a 2.5 or 3" exhaust vs stock or the borla or magnaflow at 2.25".

 

[mattyboh]

If that is the case, then really is there any benefit if you have the stock downpipe of a 2.5 or 3" exhaust vs stock or the borla or magnaflow at 2.25".

On the stock turbo, exhaust doesn't really matter. The tiny snail is the limiting factor. If you stick to the stock turbo, just get the exhaust you think sounds best and meets all of your requirements.