How much does piping diameter affect HP?

JhnRx7 · 08-08-03, 09:53 AM

I have a stock 2.5" DP that came with the Japanese engine that i have in my car. How much HP am i losing with a 2.5" DP instead of a 3" DP?

JhnRx7 · 08-09-03, 12:44 AM

is it worth it for me to buy a 3" DP now? i will eventually but i would rather put the money towards other upgrades first.

Svelte_7 · 08-09-03, 01:10 AM

Stock DP? Does that mean that JDM 13b-rew's come without the pre-cat.? In any case, I have a HKS DP that I'm pretty sure is "only" 2.5 but since it increases both Hp and longevity, I wouldn't divert funds to replace an upgrade instead of getting another. I read your mods and considering you have the intake, exhaust and boost controller on hand, it's a tossup between taking advantage of a safe 12-13 psi of boost with a fuel computer, or an upgraded intercooler that will give you an extra margin of safety (and HP) until you get a fuel computer to run elevated boost levels

I'm at no means an expert but going by my limited experience of slapping upgrades on my FD. Hopefully others will chime in...