Quote:
Originally Posted by micondie
As an old hot rodder it has always been my understanding the only part of the intake that has much effect on power and torque is the length and diameter between the intake valve and the plenum where all the ports merge.
|
I had to design an intake system for a formula SAE competition car and the intake primary runner length, and diameter are the most significant parameters, So long as the rest of your intake doesn't have any major restrictions. The intake low pressure pules are generated at the valve, and end up reflecting off the end of the open intake runner. At the right frequency a high pressure ridge is sitting at the valve as it opens, and presto! More torque.
If the intake runner is to large (diameter), it dosen't build any momentum, and volumetric efficiency is low until a higher RPM. If the intake runner is short, this also favors a higher RPM set point. Ideally, you design your cam, and your intake runners to give you a broad range of favorable operating conditions.
Back on to the topic at hand, the warm-air intake. It's something i'd love to try, but I lack the intestinal fortitude to try it! My intake air temp is always close to ambient.