LynnBob Mustang

I thought you needed back pressure...?... [8D] JK

Someone had to do it....

Lynn

6mustang6

you do want alittle back pressure for low end power. if you open up the exhaust too much you will gain top end performance and lose low end power. come on we all now that.

oxfordgt

See I told you.You don't lose low end power your powerband gets moved. You don't need lowend power except for city driving but why would you need alot of power to take off from a light while just driving. If your racing you should be launching at an rpm that you wouldnt even notice the lack of power.

dsdawg35

Hmm, I guess I don't understand. 3" exhaust causes more back pressure than 2.5"? That makes no sense. Why would they make a 3 inch collector to just go to 2.5? Also, wouldn't it sound deeper? Thanks for your input guys. Keep in mind when you answer that price difference is minimal so that's not a problem.

oxfordgt

Backpressure is caused by the pipes being to big and not enough flow which causes the gasses to slow so much that it actually starts to backup the exhaust.

livefast1

if i had a blower or a turbo i would go with the 3". its not needed on an all motor car. think about this you start with a really small hose the water comes out really fast, the larger you make the hose the slower the water will come out. you have to find a medium between the 2.

Aereon

3" dual exhaust is just way overkill on a 2v, to me thats like a folgers can on a civic. Unless your gonna be pushing 700+ fwhp I doubt you'd really see a great benefit over a 2.5" setup.
Our main problem is not the exhaust part of the equation, its our crappy 2v heads that choke harder than the rockies.

tmas99

hey oxfordgt... idk if you are in another post or not... but this guy was telling me that running open headers is not bad for your car wheni told him it was... for this reason that if you run open headers cooler air gets sucked back through the lt's or manifold and can cause the exhaust valve to warp... i know that, that is not a myth and what you just said about backpreassure just proves my theory... what do you think?

livefast1

that has absolutely nothing to do with that ^. i what he said it makes the exhaust system itself a flow restriction, if there is no exhaust at all then there is no restriction. and if running open headers is bad..........how about the thousands of hotrods that rolled around in the 60s 70s with longtubes, glasspacks, and turndowns? thats about 2 ft. from open headers and magically none of them had any exhaust valve warping problems.

Aereon

I highly doubt the air that may or may not end up going back through the headers is anywhere near cool enough to cause warping.