Variable Length Intake Runners

[BeaverGuy]

I know that there are several teams that either run or have in the past ran dual length intake runners. But how many have tried continuously variable intake runners? I know it was tried here at Oregon State a few years ago.

[Jason Hickman]

The University of Florida used Continuously Variable Runner Length Intake Manifolds in their 1997, 1998, and 2001 FSAE cars. You will find it very difficult to develop a reliable actuation system, as well as a relaible controller. All of our manifolds varied runner length dependent on RPM.

They did significantly flatten the torque curve. The manifolds were abandoned due to their complexity.

If you search there was an article written on that manifold design back in 1998 in RaceCar Engineering (I think it was that magazine... can't exactly remember for sure).