rudebwoy

iTrader: (1)

is it beneficial to run a 2.5 inch downpipe with a 3 inch catback system?
reason, that is my current setup. and I don't wanna have to replace my downpipe anytime soon.

Finland

It's a bit counterintuitive, because exhaust gas contracts as it cools when it's traveling through the exhaust system. So, if anything..having a big DP with a smaller exhaust is probably not as bad as having a small DP and big exhaust..

However..it may take more energy to push cooled down gas through the system.

Bottom line is: the bigger the better for turbo cars.

...or just go have a beer and forget the whole thing

HiProfile

Cooled or not, restriction is restriction. There's a reason that an open DP makes a good 10% more HP than a 3" exhaust. Despite all the proposed theories, nobody can argue with dyno graphs with the same car/setup/dyno in which a bigger (or no) exhaust made more horsepower, regardless of DP size.

If the smallest pipe in your exhaust was the max that exhaust could flow through the entire system, then you'd be proving that carburators CAN'T work (the venturi effect).

rudebwoy

iTrader: (1)

so what are you trying to say?
can I relax and wait till I have some spare cash , and still make good power.
or do I have to break my back get a 3" DP.
is it beneficial or not, is it no different than having a full 2.5 inch system?

rudebwoy

iTrader: (1)

I guess no one else knows, thanks anyways, I will reseach when I get home

ndogg

you can make power on a 2.5" downpipe, it will just take a little more boost to make what you would have on a 3" downpipe. what is your power goal?

rudebwoy

iTrader: (1)

500whp at 25psi sc6152e
the list is long dont ask

ndogg

for that power level it is probably worth it to go 3"

rudebwoy

iTrader: (1)

I might as well just slap aluminized steel 3 inch downpipe, I can weld, but all I have is a flux mig,
I dont like a open dump tube sound but I may have to settle for that.

quicksilver1689

the less back pressure the better, turbos create there own back pressure, the pressure difference helps the turbo create power.

rudebwoy

iTrader: (1)

just bought $150 in supplies to build my own 3" DP , looking for a small resonator with 1.5" in and out to quet the open dump I am gonna use.