What size downpipes do I need?

[Jl97]

I purchased a 2.5" twin 1 ssac catback exhaust and was just verifying that i need the 3inch to 2.5inch downpipes instead of the 3 inch to 3 inch. Is this correct?

[XLR8 Craig]

No you should be able to run a full 3 inch down pipe but have the mid pipes neck down to the cat back size.

This is assuming they make mid pipes like that.

Thanks,

Alex.

[ianwpb]

What is your setup? 3 to 2.5 should be plenty for most stage3+ set ups. You can use the full 3" though.

[christianb5s4]

What is your setup? 3 to 2.5 should be plenty for most stage3+ set ups. You can use the full 3" though.

Agree, 3-2.5" downpipes are not even close to being a restriction even at 600+whp.

[slow ride]

My Corvette uses 3" downpipes if that helps ;) Friends LS rx7 went 9.85@150 on a single 3" downpipe no exhaust.