Extractor tuning - Anti-Reversion Headers

[oldeskewltoy]

I've seen many different designs... Before I'd worry about anti-reversion I'd 1st be making sure my lengths are appropriate, the diameter is appropriate, the merges are appropriate... then I'd be concerned with either a stepped design or anti-reversion design.

[Radar]

You mean get your exhaust velocitys right before worrying about anti reversion?... I'm aiming for around 400ft/sec exhaust velocitys for best TQ So far the best exhaust I can seem to come up gives me pk 217ft-lb tq and 329hp with an avg of 181ft-lb and 171hp.
To do that I needed 57"@1.46" -> 3"@1.75" -> 36"@1.49"... I understand what your saying by lenght and diameter is more important. But by the looks of it once a certain amount of overlap is introduced the anti reversion chamber seems to be just as vital to get rid of the pressure waves caused by the inerter tuning.