Thread: Headers and cat-back

SD headers are leaking at the flex and since I now am running Gen V, S1X, Intercooled I am looking to step up to a pair of used WBS or ZZP headers. Cat-back is also rusted out so looking for an aftermarket 2.5" or 3" system used that is fairly close to stock in terms of volume.

Again: Used WBS or ZZP headers / used 2.5" or 3" quiet cat-back

Why not fix the flex for cheaper than buying new headers??

There is no upgrade in flow with other headers.

Ur telling me that with an s1x cammed, intercooled gen v with a 2.8 pulley running 12-15 psi knock free at 18 degrees that i am not outflowing headers with 1.5" primaries and a 2.25" crossover and would not benefit from 1.75" and 3"? Also when I bought the car the SD headers were already on it so it's not like I am wasting money on a new set completely.

The catback i could understand and is why i dont care if its even a stock one with no rust.

Ur telling me that with an s1x cammed, intercooled gen v with a 2.8 pulley running 12-15 psi knock free at 18 degrees that i am not outflowing headers with 1.5" primaries and a 2.25" crossover and would not benefit from 1.75" and 3"?

Correct, you are not outflowing them.

Turbo dudes run 2 plogs with 2.25in piping to the turbo then a 3in downpipe and they push 450+ whp.

Originally Posted by Fivefingerdeathpunch

Correct, you are not outflowing them.

Turbo dudes run 2 plogs with 2.25in piping to the turbo then a 3in downpipe and they push 450+ whp.

I think that is a completely different scenario where you are running an exhaust pressure driven boost device vs a blower which needs flow. Please direct me to some GP's running 12.0-11.6 on SD headers....hell even dynoing 330whp+ on SD headers.

Headers are headers are headers for these cars. Its just how much money to want to pay for them, as in quality wise.

THe outlet of the head is 1.5, and thats the same size as the SD headers primarys. Going bigger to a 1.75 won't do any good, it'll just give the exhaust a place to swirl and make turbulance, but really it wont even be noticed or affect anything. So going bigger wont do anything. The 2.25in crossover is big enough for 3 cylinders and the straight pipe design on the rear header into a 3in collecter just like on every other header(s) offered, so where are the gains from buying different ones?

The only gain is not having slip joints and a prone to leak flex, both of which are easy to get around.

Originally Posted by matt5112

Not that I can say I agree with your claims of power or ET limits, I can say I agree a turbo hot side piping cannot be compared to a roots setup.

I also agree that ZZP headers would be ideal here.

I'm not 100% sold on WBS, they appear to be OBX with a new crossover/collector/downpipe. One could ask the same demands of dynos and time slips for these headers as well.

Well I had just pulled off the front header and crossover from these SD headers I have. I.D. measured 2.0" on the crossover and only 1.5" on the primaries...I am pretty sure some gains are to be made going to a 2.25" crossover minimum and 1.75" primaries at my current mod level. My demands may be a bit much but when you start comparing things that aren't alike without even mentioning one example on another car of how my current headers can capably support my setup I get testy. I know he was just trying to help but this is a WTB thread. I would gladly spend my $ on some used bigger tube headers.

May not be this bad of HP limits but even if this table is wrong by 50%. How To Calculate Muffler Size and Exhaust Pipe Diameter | Exhaust Videos

You will only benefit from larger primaries once you have ported heads.

I have seen and heard of gains from going to larger primary headers, but only once the use of ported heads came into play.