An Experiment without Shocks

[davidbrady]

Morey,

What I'd really like to do is find a way to lower the resonant frequency. Prevost did it using auxiliary reservoir tanks, but they also added conical bump stops to the inside of the air springs. This gives them a soft initial spring rate when the suspension moves in short strokes but a very aggressive spring rate when the suspension moves in long strokes. (The spring rate curve has a pronounced knee). We don't have this option. Clearly Prevost added conical bump stops because they needed to. If we added reservoir tanks we may find that the suspension quickly bottoms without conical bump stops! The other alternative is spec-ing a different air spring - one with larger internal volume. We have to go wider since we can't go taller but I don't think there's room for any addition in air spring diameter. Alas, it is what it is! And, truthfully, it's actually quite good when set up right. Slightly on the stiffer side but it still handles and rides well. Admittedly I'm looking for that last 10%.

If anyone wants to know what true Blue Bird Bounce is, then take a spin around the block with no shocks. Wow! This little exercise completely reset my notion of what a misbehaving bus is really like. Koni deserves a gold medal for providing a heavy duty shock able to tame the beast without terribly compromising ride. This experience taught me that the 90-2947SP1 Koni on full soft is nothing short of fantastic. Now, folks may say it still bounces more then they'd like, but be aware that every little bit of bounce control that is dialed in results in a harsher ride all around.

Morey, someday I'll do back to back tests of the adjustable Koni's versus the FSD's on the Tag and Drive axle. I'm running FSD's and I like them but it's hard to say just how different they are without testing them back to back.