I have a 1993 honda civic vx with an H22A. stock head/ components, slight port on intake, try y header from highend motorsports, 3inch outlet. and a password JDM whale ***** intake with 6 inch inlet.and a programmed P-28 with a S300, about to get tuned in like 3 weeks. i was wondering if i got the K tellers piping kit should i stick with my 2.5 inch setup or can i go to a 3 inch? I wouldlike to know facts not oponions please, such as power losses/ power gains for the two sizes. thanks alot HT. posted this on the civic thread as well, any response welcomeas long as it applies.

 

If you search you'll find your answer.

 

4inch

 

2.5 inch should suffice just fine. if you were boosting then i would say 3 inch

 

I believe test's were done while back and the 3" made more power. However I could be wrung because I researched that a long time ago.

 

3 inch makes more power. h22's like to breath. Sounds like you have a good amount of mods that would definitely compliment a 3".

 

I vote for anything that works and isn't louder than stock. No need for more annoying 200hp Honda's driving around. Kthx.

 

The header collector will do more to determine the power output and range than the exhaust system will... but since it is 3" already I'm not sure why you'd go down to 2.5". Several tests here have shown 3" to make gains across the board, however, a couple of those were crush bent and I don't recall differences in cats and/or mufflers that could have made up some of the difference. If noise is a concern, go 2.5".

 

x2 on these.

If you want more information - than as already suggested: