okay,

Would there be any performance difference on a EVO with just a stock cat and 3" exhaust cat back with a 65mm (2 3/4") Downpipe versus a 75mm (3") downpipe both tuned on a XEDE? If so what would it be?

Thanks!

 

I would tend to think that it would be very close if not identical at that power level.

 

bump!

 

With the caveat that this is on a Integra, moving from a 2.5" downpipe to a 3" downpipe (I had to move A/C to make it fit) did make a difference at higher boost levels. 2.75" is close to 3" though.... Are you going to be running race gas?

 

No, I will not be running race gas

 

i have an hks 65mm dp, ur 3" cat and jic 3" ti catback and my car made more hp than several other evos at the nj tuning day w/shiv last oct. all of them running 3" dp. one person was contemplating getting rid of his 3" dp to duplicate my set up and get that 5 extra hp. so, i don't think it makes a difference at all and he probably wouldn't have gotten the extra hp changing... just car to car difference.

 

The only way to find out for sure is to conduct back to back dyno testing on the same car/setup which I plan on doing if I ever get back home.

 

Got my interest. Lets us know how it goes