[QUOTE=AndyFloyd,Sep 22 2009, 08:50 PM] Oh I agree Chad....but the question was " would a 4" make more power over a 3" @ 600whp " I bet it would. Would love to see a dyno but we probably never will...and I will never need a 4" so I wont ever know. But physics kinda dont lie.

 

im all for a big exhaust. not that this helps you on 3" vs 4" but the basic concept is there. this is 2.5" vs 3" on a 2.2L h22

 

Great info Joe, have you ever had the experience changing from a 3" to 4"? Thanks for that chart.

 

What are all the variables here? Same turbo, boost, etc, etc? If it's not all completely the same except the 2.5" to 3" exhaust swap, this info is null.

 

not with out changing too many other things to do a fair comparison. usually a turbo upgrade at the minimum was done at the same time. i have probably made 20+ 4" exhausts though. they work. im torn if i want to do 3 or 4 on my s2k once i get around to putting a stupid turbo on it lol

 

do a 4" and prove that it makes power at the same time. Make a 3" and 4", just because you want the extra work and you like to weld and spend money for no reason.

I cant wait to see what you do with teh s2k.

 

the dyno chart above is no changes other than the exhaust. sorry, probably should have posted that.


first thing is finding a plug and play ecu solution thats not aem and is more flexible than hondata. do that, get it running good as is. then throw some turbo parts at it. lol

 

[QUOTE] As for 2.5" vs. 3.0", the "best" turboback exhaust depends on the amount of flow, or horsepower. At 250 hp, 2.5" is fine. Going to 3" at this power level won't get you much, if anything, other than a louder exhaust note. 300 hp and you're definitely suboptimal with 2.5". For 400-450 hp, even 3" is on the small side.

 

I make a motec PnP system... obviously not as cheap as either of the two you mentioned but then again obviously there is a reason you don't want to use those

 

if you got the adapter harness, name your price and i will probably buy it. i have an m800 ready to plug in. i was thinking of making one, but since i drive this car every day i dont want to keep the ecu in it all the time. i'll use the other plug and play alternative so if the car gets stolen i wont have to sweat it too bad haha

would love to put the m800 in it on the weekends though (god that sounds absolutely retarded). much easier to learn a system on a street car than a race car. at the end of the day, thats what its all about for me and this project.

shoot me a PM!