XLR8NSS

iTrader: (4)

Just a quick question on downpipe sizing. How big a pipe would you need for 300-400hp? I was thinking 3" would be OK and probably not cause any interference problems with what I was thinking. 3.5" could probably be made to fit though if 3" isn't big enough. The downpipe will go right down and dump out a cutout so it won't be too long.

Thanks

MYTURBOT/A

FWIW Rob made 700hp through a 2.5in down pipe.

GMC SKI

From what i have been told 3" should support upwards to 1000 hp
and does on a regular basis

smokinHawk

iTrader: (48)

you really need a 3" if making over 500rwhp

for turbo, the bigger the better
only problem in a fbody its hard to get a big one in
what kit are you talking about?
on the QMP, and turbotech, 3" is about the biggest you can get, and thats hard to squeeze in.
ive heard of a 3" CAS (dual for twins) but it looks like it tapers to the 3"

SS00Blue

Yup. If you can fit a 24" sewer pipe, do it. Turbos HATE HATE backpressure. But the 3" seems to be more than adequate to blow the rear-end out of a car.

SC-

XLR8NSS

iTrader: (4)

What about a 4wd truck?

So it seems short 3" downpipes off each turbo will be more than adequate for up to 1000hp total. Ummmmmmm......That should do it.