Headers 101
 

I'm looking at the slippery slope for the 3.0 in the 912-6. 99%track car at this point. I'm considering the set of headers I have hanging on the wall and if I will gain anything other than more decibel's. Right now I'm running stock HE with a cat bypass pipe into a stock 1/1 muffler.

Do I need to upgrade the cams to make best use of the headers?

For mufflers, should I use Ben's race mufflers, or maybe a flow-master 2/2?

Headers aren't a one stop shop. Primary length can tune your powerband just like cams and port size can. You should measure the ID of the header pipe and quote your exhaust ports as a start. Are the primaries equal length? If so, measuree one (from inlet to the merge) and reply with that number, too. That should give enough info to give those smarter than me the opportunity to tell you what you need to know.

I think you'd see somewhat of a gain, but it might be difficult to quantify. One thing that I really enjoyed with headers was the weight reduction. Getting those heavy factory heat exchangers and factory muffler off the rear of the car was really nice.

Removing weight from the rear of the car is always a nice thing.

Mike

I'll get some measurements tonight and post them. Believe they are equal length. Motor is a large port 3.0

Thanks guys!

For headers to work to their design specs they do need more overlap to bite into than is provided by stock smog cams.

W/O the overlap then the primary benefit is only in improved flow volume. This can be fairly significant(or not) depending on the efficiency of the stock exhaust.

ssi headers are their equivalent w/o the heater box covers will provide a small improvement in flow as will a freer flowing muffler.

Just don't expect miracles w/o cams, ignition and fuel enhancements