Okay heres what gets me.......you dont want any back pressure, correct? Well if thats true then why is 3" exh too big for a naturally aspirated engine? Like running open header, no back pressure and more power, but with 2.5' exh and 3" exh the 2.5" is considered better....why?
Will some knowlegable person(Mrfatbooty for ex.) please help me answer this question?



Thanks alot
-Chase

 

its all about exhust velocity. You want the least amount of back pressure, but you want the exhuast to flow quickly. Having a smaller diameter exhaust will create more velocity than a larger exhuast, which is why you can loose power when you get too large of an exhuast, of course if you get too small of one you have back pressure which is bad. The key is to find something in the middle that is small enough to have good flow, but not so small that you choke your engine.

 

Check out this thread as well:

https://www.honda-acura.net/forums/s...e&pagenumber=2

Shingo

 

check out the exhaust tech articles at the very bottom, this answers EVERYTHING: http://www.team-integra.net/sections...les.asp?Show=1

got pictures and GOOD explanations..check it out.

 

Cliffs notes:

Backpressure BAD. Exhaust velocity GOOD.

If maximum exhaust velocity was possible without backpressure, the world would be a better place. However, that doesn't exist. You want a combination of lowest possible backpressure and possible highest velocity.

 

more cliff notes: you want the diameter to be big enough for the exhaust gasses to flow at the highest rate possible before being restrained, basically what he said above

 

Hellsing ownz me :thumbup: I only wish they made more, 12 (i think) isnt enuf