I've been looking around and searching but couldn't find a 'good' answer to which test pipe would give power gain and not power loss. I know I would not gain that much, but im just starting to add bolt-ons in modifying my S.

The test pipes i've been looking at were:

-60mm invidia tp w/ cel fix
-70mm invidia tp w/ cel fix
-60mm berk tech w/ cel fix
-63mm megan racing tp w/ resonator built in and cel fix
-63mm skunk 2 tp w/ cel fix

I've been told 70mm would make me lose low end, and 63mm would also make me lose low end. But 60mm would be perfect with no low or high end loss.
Anyone have any experience with any of these?
Anyone know the facts on power loss and power gain from the diameter of the pipe?

And which ever tp is better, im going match the same diameter with the whole piping after the tp.

Thanks in advance.

 

so bottom line... there all about the same,
the size in mm will only be the main difference in the sound

but people say it sounds different from each company
i find that it all matches up with what exhaust you have,

if its stock i would go with the invidia,
or if you have a berk exhaust i would go with the berk test pipe

etc, etc,

 

Match your test pipe size to your exhaust size. If you want a 70mm exhaust then get a 70mm test pipe. Brand doesn't make much of a difference. Can get a couple anti foulers to prevent the cel from coming in.

 

^Agreed.

The whole big exhaust for high RPM power and small exhaust for low RPM power is 100% false. Everything after the collector, is one big restriction. Don't believe me? Look at any big exhaust vs small exhaust dyno. The results will all be the same; assuming the ECU can adjust to compensate or you have an EMS.

 

so if i go 2 1/4 (60mm) from end of downpipe to stock muffler i wouldnt lose power, but gain some? if so im going with that.

Thanks for the help.

 

All depends on which exhaust. OEM is 60mm. So you might not gain much if any. A test pipe should free up a few hp however.

 

Always try to match the test pipe size to your exhaust size. If you're keeping the OEM exhaust for now, just get the 60mm. I have a 60mm invidia I had with my old HKS exhaust, and now have with my OEM exhaust and it even makes it sound better. It has more of an exotic tone to it and helps drone even more than a cat will if you ever got an aftermarket exhaust. The smell isn't bad at all, I hardly ever notice it. I was scared to get one at first because of the people talking about the smell, but most of them just exagerated and you hardly ever smell it, and when you do it's not bad.

 

^ just curious, but why did you go back to an OEM exhaust over your HKS?

 

I loved the sound of the HKS but I swapped to an ap2 rear bumper and didn't really like how it looked with it. Also i'm planning on getting a supercharger and will probably do a custom 3" dual setup to get the most power out of it, and the 60mm exhaust won't really cut it. So I sold it and put the oem exhaust on for now until I upgrade.

 

I'm thinking of getting a TP also. Save me from crawling under with my callipers. Are AP2's 60mm also?
A friend of mine said this could have an adverse effect because of change in compression, but if your saying it may gain a few hp then I guess he's wrong. I was thinking as the CAT ages & clogs it would definately have an effect!