2.5" or 2.25" exhaust for klze N/A

Sean Mandell · Post by **Sean Mandell** » October 12th, 2003, 5:23 pm

I am thinking that 2.25" might be better if I have headers. All I have is a CAI,65mm" TB,Ps clone ss headers.

Mnemonic · Post by **Mnemonic** » October 12th, 2003, 5:38 pm

babyblueMX3 · Post by **babyblueMX3** » October 12th, 2003, 6:34 pm

yeah i have 2.25 and think i should have went with 2.5

Spydie · Post by **Spydie** » October 12th, 2003, 6:41 pm

general rule of thumb.....1" per litre
in other words, 2.5l = 2.5" and so on
over 3l is where it's a good idea to do dual exhaust. You should never see a 5.0 with a 5" exhaust but you can see two 2.5" to 3". 5" exhaust would be gross

<small>[ October 12, 2003, 10:14 PM: Message edited by: Darren Hyderman ]</small>

Sean Mandell · Post by **Sean Mandell** » October 12th, 2003, 7:19 pm

Originally posted by babyblueMX3:
yeah i have 2.25 and think i should have went with 2.5

Why do you think this?
I have thought about this and I beleive 2.25 could be sufficient.

thebonestockkid · Post by **thebonestockkid** » October 12th, 2003, 7:36 pm

Originally posted by nvrsrndr:

Originally posted by babyblueMX3:
yeah i have 2.25 and think i should have went with 2.5
Why do you think this?
I have thought about this and I beleive 2.25 could be sufficient.

2.5" piping is better for DE/ZE engines because it wont be as restrictive on your top end, and it will let more overall power pass thru.

r1cer4l1fe · Post by **r1cer4l1fe** » October 13th, 2003, 4:12 pm

You dont want to go to big though or you start loosing power.

TsiMiata · Post by **TsiMiata** » October 13th, 2003, 8:24 pm

As a point of reference my MX-6 did 152whp with a 2" OD Borla exhaust and a 2 1/4" test pipe. Lets say thats 187 flywheel. A 2 1/4" OD exhaust is ~28% bigger in cross section. So lets assume it will support 28% more power. 187hp*1.28=239hp. By the numbers it appears a 2 1/4" exhaust will more than support a 200hp KLZE. If your looking to do nitrous or some big add on later 2.5" might not be a bad idea. If your going to be running a mostly stock KLZE with bolt ons then 2.25" should do OK.

Granted these are all assumptions based on one set of dyno runs on one car and not knowing what the limiting factor was for power. Maybe something besides the catback was holding back power. Then a 2 1/4" might support more than what I listed above.

Zoso124 · Post by **Zoso124** » October 14th, 2003, 11:15 am

I agree, stick with 2.25".

UrBaNsTyLe55 · Post by **UrBaNsTyLe55** » October 14th, 2003, 3:13 pm

yuh i recently did 2 1/4 header back on my car, and wow what a difference, unless your going with a nitrous or turbo set-up, go with 2 1/4 and if you decided later to go nos or turbo then do the 2.5 piping

ohthehumanity · Post by **ohthehumanity** » October 15th, 2003, 12:11 am

yea just curious...does anything need to change your cat. converter if you go with some bigger pipes?

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2.5" or 2.25" exhaust for klze N/A

2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A

Re: 2.5" or 2.25" exhaust for klze N/A