quote:Originally posted by PanteraDoug: One race header builder that I know, "cc's" the tubes!
I think if you can get them within 2" AND be able to get them on and off the car, you are an over achiever.
I don't know exactly how close the GT40 tubes were on the race cars but if they were within 2" I'd be shocked?
Thanks Doug. As far as I know exhaust tune is a function of harmonics which is modeled by wave theory. The operative factor in doing so is length of the primary. I had never thought about cc’ing a primary. I have my doubts whether volume would be a better predictor of length traveled by the wave of the exhaust pulse. The cross sections of even mandrel bent tubes aren't consistent enough and as I previously mentioned, I doubt the pulse feels compelled to travel the centerline of the snaking primary, but to the extent to which volume predicted length more accurately it could be helpful.
I do think the volume can be a predictor of the gas velocity and mechanical efficiency or losses, but the pressure wave is sonic.
If I was racing on TV on Sunday afternoons it might matter. My Pantera will never know the difference even if I did