[marklim]

As above, Would 3" Midpipes yield any benefits ?

[john boxter]

if u had 3 inch downpipes they definatly would. we saw 2.5 to 3 inch downpipes yeild 7 whp and those taper back down to 2.5 inches therefore if we keep the 3 inches all the way we can definattly expect gains.

[marklim]

hmm... similar observations.. but if that's the case, does the mufflers have to be 3" pipes as well ?

[GreenPlease]

IMO the biggest gains would be seen with secondary cats. A 3" turbo back exhaust with secondary cats (no primaries) should see nice gains over a 3"->2.5" system.

[JoeyFiasco]

what's the difference in flow between 2.5" and 3"?

[ar design]

2.5" will flow fine to over 600whp.

[marklim]

i understand that on turbo cars, less backpressure is better.

however, is it possible that less back pressure is better only for high-end power?

i'm asking because i've been told that less backpressure cost a significant loss of power during low end.

and i don't know if its the placebo effect, after my downpipes installation, i tried driving around without midpipes and mufflers (exhaust gas coming out from downpipes directly) for around 30mins and realized that the car is not as responsive.

[JoeyFiasco]

Originally Posted by ar design

2.5" will flow fine to over 600whp.

if that's the case, most of us have nothing to worry about

[UAP1]

I would think you would see bigger gains and benifits once you are in the 550-600 plus range.

However, I would be VERY interested to see if any gains are made in the 350-500rwhp range.

Someone needs to give it a run and datalog it!