Stick With 3" Or Go 3.5"

[MANWHORE]

3" should be fine for that power. I'm running 3.5" straight pipe no muffler only because I like it loud.

[legend01]

I run custom 3" front pipe to catco stainless barrel cat 3.5" to the resinator 4" from there to the cannon its a hks exhaust .I picked up 12rwkw when I did thisover my old 3" exhaust and that was a trial

Cheers Peter

[sandyb]

I went from a 3.5" mild steel, to a 3" stainless and lost 4kw at top end - gained 5-6kw from 2000-6000rpm. R32GR 237rwkw. Think it depends on your power level as well as cats/mufflers/diameter.

Cheers, Sandy

[mad082]

I went from a 3.5" mild steel, to a 3" stainless and lost 4kw at top end - gained 5-6kw from 2000-6000rpm. R32GR 237rwkw. Think it depends on your power level as well as cats/mufflers/diameter.

the reason you gained mid power was because the air could syphon a bit better with the smaller piping, but at top end you had obviosly maxed out that size piping.

or it could've been due to different whether conditions, etc etc etc.

Edited April 4, 2007 by mad082

[Mr. Keets]

A few ppl have mentioned it but it bares repeating..the most restrictive thing in your system...is the cat, provided your system wasnt manufactured by a complete loser. I changed to a "spec R" cat on a 3" mild steel system with x-force dumps and genie front and cat back. I picked up 20 HP at the wheels on my 32R. Next time I'll go a better quality hi flo cat and go bigger dia dumps and front.

[sandyb]

the reason you gained mid power was because the air could syphon a bit better with the smaller piping, but at top end you had obviosly maxed out that size piping.

or it could've been due to different whether conditions, etc etc etc.

They were back to back runs so that eliminates several variables, either way, power level only slightly differnt - barely noticable, but the differnce in noise was considerable.