ok so ive heard that 3" downpipe is too large to use with n/a. but i would like to know why. what type of performance differences would be had between the two sizes. currently i have a short ram intake and a tsudo catback.

 

Any 2.2 running a 3in downpipe?

 

Only ones that are turboed

 

That's what I always hear. I contacted zzp and zoomer said that the difference in power I would see from the 3in vs 2.5 would be 1-2 ft lbs of torque. So I assume that I would not gain as much low end but a little more high end. Thank you for commenting appreciate the input

 

i assume your na, may i ask why you would consider a 3"?? NA's need some backpressure whereas forced does not. I mean, low end turbos dont even need a 3".

 

what do you mean by "low end"? you referring to small?

 

low end HP..such as low to mid 200's.
*edits* hes refering about DP not whole exhaust(I hope), I have a 2.5" header back system with the new turbo setup and feeling Peerty goood. This is all from MY past/current situation(s), so i may be a little off.

 

from what ive always been told, when you start goin around 300 a 3" is needed, but less that that a 2.5" will be alright

 

yes just the downpipe the rest of the exhaust is 2.5

 

And the reason why I am considering the 3in is because zzp is out of stock on the 2.5

 

I would just wait for the 2.5 inch one if you can cause there really isn't a need for the 3 inch one. At least in your case.

 

Ur gonna want the 2.5 the 3 inch you will have zero scavenging which a NA car needs. Get a 2.5 catless for the best results IMO

 

Well the 3in is on the way. Can't wait to see how it turns out. What do you mean by scavenging? And it will be catless

 

Catless is gonna be hella raspy lol

 

Ya lol it should be here on Monday I'll post a vid when I get it on

 

i honestly think youre going to overkill it.

heres info on scavenging http://en.wikipedia.org/wiki/Scavenging_(automotive)

 

3" is too big, if it hasn't shipped out yet, call them and ask them to hold off on shipping and to just ship a 2.5" when it's available...

 

Hmmm interesting, thank you for the info. Guess I'll find out how she runs cause it's a done deal

 

Well there goes your exhaust velocity. If I was an na 2.2 and I wanted some 3 inch tubing in my exhaust I'd want it to be as far from he head as possible. Though honestly I wouldnt want it at all.

 

Agree, 3" is probably going to be worse than the stock piping. Waste of money IMO, but he didn't want to listen to people in the beginning of the thread so why would he listen now. Ignorance is bliss...

 

Well he will be slower than stock now. 3" is only for boosted or n/a apps 280bhp or better. You'll never see that with a n/a ecotec.

 

I don't see how I'm gonna be slower than stock. I'll post up some slips when I go to the track after the install and I'll see what happens my best time so far is 15.5

 

2.5" catted downpipe for your car.

3" is much too large and will end up causing eddies and decrease exhaust gas velocity.

 

You do not understand fluid flow.... Bigger is not always better!

 

Have you modified anything else since you ran the 15.5? Make sure you post slip-slip so we can see the comparison of full runs...