right now running a full 2 1/2 from turbo back, would it be worth it to get a 3in dp and keep the 2 1/2 exhaust? Really dont want to replace the exhaust if i dont have to. Im running around 300hp if it matters

 

i wouldn't say its worth it, now if you put the 3in downpipe on and took the exhaust off and got it retuned, you'd make more power and have better spool

 

There was a car we had a hand in a while back, and it seemed to have better spool with the exhaust.....? It didn't really make much sense.

 

my 30r spooled faster with the crush bent 2 1/4in exhaust i used for inspection than it did w/ open 3" downpipe... weird.

i wouldn't say it's worth it so to speak, but it won't hurt ... and if you ever go bigger later, it's just one piece you don't have to worry about.

 

my street car last year had a 3inch dp/2.5inch exhuast. (450hp 315 tq @18psi on pumpgas from t3/67) my point was to try to keep it more quiet, as opposed to a full 3inch which probably would have been a bit louder.

 

i went to 3" from 2.5". as same time i went to 2.5" IC piping, larger air filter and 38mm wastegate from 35mm.. made 30 more whp at same psi. not sure which one contributed more.. but overall isn't much louder and pretty quiet when cruising.

 

More info on this, Im debating on going to a 2.75 inch exhaust after my 3 inch dp

 

its fine stock exaust and an eletric cut out is wheres its at anyway