"J.B. Hebert" wrote: > > The '89 to '94 SHO Tauruses had some of the first variable length > runners on a production car (or the first to work really well).
I believe the SHO had the short fat runners cut off by butterflies which opened at a certain RPM and throttle position. I seem to recall a few attempts at telescoping runners, but nothing that would work reliably for 100,000 miles. The idea is to set up a pressure wave when the intake valve closes, have it reflect off the opening at the other end of the runner, and return to the engine side while the intake valve is open. If I build a manifold for an OM6x turbo, I'll try to set the length so that it works from about 2200 to 3000 rpm. After that, the turbo should make runner length less important. Mitch.
