We all know that the bigger is better on turbo cars because the exhaust flow drives the turbo. How about SC? What size is more ideal? Not too small and not too big? Any input?

 

superchargers still need backpressure, stay with 2.5inch all the way back for under 10 psi. From personal experience, that made more power than a 3inch. I used to have kami header, 2.5 inch straight pipe. made 10 whp from 3k to redline and didnt sacrifice any in the low end, but didnt gain any in the low end ethier

 

Yes, 2.5" works great. That's what I ran when my car was supercharged and it worked well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BxCrx91 &raquo;</TD></TR><TR><TD CLASS="quote">superchargers still need backpressure, stay with 2.5inch all the way back for under 10 psi. From personal experience, that made more power than a 3inch. I used to have kami header, 2.5 inch straight pipe. made 10 whp from 3k to redline and didnt sacrifice any in the low end, but didnt gain any in the low end ethier</TD></TR></TABLE>

I still has doubts about engine needing a backpressure. It needs good flow redirection and that's what a header does. It also needs smoother and easier flow, not backpressure, right?

Any good article or thread on this?

 

elpiar,

Thats what I have doubt about. How much back pressure is needed with a SC? A few? None? I have problem getting the answer because SC isn't common on aftermarket industury. I guess everyone likes the turbo more.

 

I replaced my broken/leaking GReddy SP1 with the new(titanium coating) Apex'i World Sport 2 Exhaust. My car now runs more responsive. That shows me the leaking exhaust (more flow/less back pressure) is not as efficient at the low-end power.

At least, now it tells me that a specific back pressure is necessary on SC setup.

BxCrx91,
Do you have a hi-flow cat too? How big is the opening on yours? Also, do you feel any lags @ 2,500-3,000 rpm when you step your pedal all the way down? Please let me know.

 

pm'd

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by E-gg’s &raquo;</TD></TR><TR><TD CLASS="quote">I replaced my broken/leaking GReddy SP1 with the new(titanium coating) Apex'i World Sport 2 Exhaust. My car now runs more responsive. That shows me the leaking exhaust (more flow/less back pressure) is not as efficient at the low-end power.

At least, now it tells me that a specific back pressure is necessary on SC setup.

BxCrx91,
Do you have a hi-flow cat too? How big is the opening on yours? Also, do you feel any lags @ 2,500-3,000 rpm when you step your pedal all the way down? Please let me know.</TD></TR></TABLE>

you lost low end power because the broken exhaust was causing turbulence, which greatly inhibits flow, not because of the loss in back pressure . Superchargers don`t need backpressure while in boost but out of boost they need as much as any NA cars. Turbos on the other hand have a shitload of backpressure from the turbine housing itself so after the turbo bigger=better

 

ProjectDarkBlack,

Yes, you are right. I mean I needa higher exhaust flow speed instead. We don't want back pressure.

I my new WS2 exhaust has 60mm piping. Does anyone has lags running the same size pipes with SC? It now runs better but I still feel the lack from 2500rpm-3000rpm, especially the WOT on 3rd gear and up in those rpm ramge. Anyone knows the stock piping size?