am i right or is he?
 

So today after school my friend had his buddy come down, I had previously told my friend that I thought his buddy was runnin to bix of an exhaust, hes running 3" with port polished e7's and hes telling me im a f*&@ing morong and that he went to nascar school to learn about engines and the only reason he would ever need backpressure is if he was running a turbo. He told me a 5.0 never needs backpressure unless its turbo'd....Whos right? me or him do 5.0s need backpressure?
(p.s than he procedeed to roast his tires and really show his dented rusted 91 hatch 5.0 was a piece by pullin a 1 wheel peel all the way down the driveway after neutral droppin it........and the dean of the school was there and got his tags :))

RE: am i right or is he?
 

hes right

RE: am i right or is he?
 

[:'(]

I think you are right, they need some back pressure, I think though that the more powerfull engines don't need as much...

RE: am i right or is he?
 

I am not sure about that. I have always heard you need a certain amount of back pressure, but I would do more investigation of the subject.

RE: am i right or is he?
 

ive been told over and over that unless u got 400hp+ a 3" exhuast is to big and is likely to rob u of hp

RE: am i right or is he?
 

ive seen a chart in a mustang mag once before that had a hp to exhaust pipe comparison and a stock 5.0 doesnt need anything more than 2.5 inch pipes. 3 inch just looks too big for the motor anyway. if it really helped that much wouldnt u see more adds for a 3 inch hpipe vs. a 2.5 inch??? but hey let him think what he wants. just do your think and he can do his and see who wins at the end of the day, right?

RE: am i right or is he?
 

I heard the same think you two just said, and i heard it hear and in magazines, but wahtever i dont really care my car is alot cleaner than his :-D His was all filthy inside and muddy and dented and scratched :-( she needs some tlc

RE: am i right or is he?
 

3 inches on ported e7's even with supporting mods is too big. It will rob you of a lot of low end torque. Hell 2.5 will rob you of a little bit of torque down low if your pretty much stock. I'd never go over 2.5 unless I was running boost.

RE: am i right or is he?
 

In my opinion, your friend has it exactly backwards. With a turbo, less backpressure is better. W/out a turbo, and under like 450 hp, he's doing nothing but losing power. I'm damn near sure about this.

RE: am i right or is he?
 

Under around 450 with 3 inch u are goin to lose horspower ( unless 2 into 1) and u need some backpressure on the motor or it wont ever ru to full potential and turbos create backpressure