exhaust pipe dia

[Fourm1]

Any thoughts on exhaust pipe diameter most companies out there are selling 2.5 inch where there is few with a 3". Anyone feel there is a performance difference or just strictly a sound thing.

 

[re-rx7]

Im running 2.25'' and make the same numbers as everyone else with 2.5. Dont forget exhaust velocity also plays a part in the overall performance.

 

[Fourm1]

oh i know i was just trying to get the thoughts of others that might have done some testing input from both parties just to see how this car reacts to the different sizes

 

[_Hunter702]

Im running 3 in and i thinks its a sound thing untill you upgrade the turbo.

 

[lessard.dcj]

not too sure if velocity is a factor as much for a boosted car, but im running 3" TB wide open!

 

[airjor13]

Anything that's out on the market right now is more then sufficient for exhaust flow. Even with the EFR / GT / GTX coming down the line, 3 inch DP into 2.5 or 3 inch TB is more then sufficient.

 

[re-rx7]

2.5 is adequate up to 300 or so. I will upgrade to it when I get my larger turbo.

 

[MrClean]

As everyone before me has said, there's no reason to have 3'' piping on the FiST until you upgrade the turbo.

 

[Fourm1]

Pretty much what I was figuring. Just wanted to see if others had the same opinion thanks for the input. I got a 5" turbo back on my truck lol

 

[COBB Tuning1]

In our initial testing, we found that a 2.5" exhaust provided more consistent power results.

Ian

 

[re-rx7]

In our initial testing, we found that a 2.5" exhaust provided more consistent power results.

Ian

Numbers?

 

[COBB Tuning1]

Numbers?

I'll see if we can dig up the old dyno plots, but the difference was in consistency, not absolute numbers. For example, if a stock car was about 160WHP/210WTQ, with a 3" CBE, it might do one run around 162WHP, then 150WHP, then 155WHP, etc, something different every time. With the 2.5" exhaust, we would see the same numbers on every pull (at least until the FMIC would heatsoak, ha!).

Ian

 

[re-rx7]

I'll see if we can dig up the old dyno plots, but the difference was in consistency, not absolute numbers. For example, if a stock car was about 160WHP/210WTQ, with a 3" CBE, it might do one run around 162WHP, then 150WHP, then 155WHP, etc, something different every time. With the 2.5" exhaust, we would see the same numbers on every pull (at least until the FMIC would heatsoak, ha!).

Ian

Gd info. Yea stock ic is for the birds.