Larry Herman

Rebound does 2 things. Here's the quick and dirty:

On the wheel side, it allows (or inhibits) the wheel from returning to the road once the suspension is unloaded, say like on the back side of a bump. Too stiff, and the car will loose grip and be jerky over undulating surfaces which load and unload the suspension.

On the body side, it keep the car from feeling "floaty" and prevents it from rising up off of the springs over the crests in the road.

wanna911

More rebound does those things? or less?

Wouldn't you want the wheel to return to the road and quickly as possible in both cases because if it stays too close to the car it doesn't absorbed the impact as well and unsettles the car?

Larry Herman

More rebound prevents the suspension from expanding, the exact opposite of compression.

Remember that your suspension is not anchored to a fixed point. The car moves and floats and rises up off of the springs. The more compression damping you have, the more it will do this. So you need rebound to keep this from happening, but too much will prevent the wheel from returning to the road quickly enough. It's a compromise.

wanna911

I knew there would be something frustrating to deal with.

Professor Helmüt Tester

"More diddles" = "more possible wrong combinations of settings".

Jus sayin.

Veloce Raptor

Dez, I have a very useful PDF that I will email you on this...

wanna911

So would I be correct in saying that rebound is a way of mellowing out the bump setting? More bump should result in less rebound (assuming there are bumps/curbs and the track isn't smooth).

Question, does rebound start from 0 or does it start from compressed state? So if you go hard right hander with heavy load on the left side of the car, does the rebound prevent the car from returning to 0 or level faster too, or just beyond 0 into expanding from the ride height level.

wanna911

Dupe!


what's up with thise site today, there are dupes everywhere?

Larry Herman

I don't feel like that is the right way to look at it. It's more of an equal but opposite situation. Generally, the less compression damping you have, the more the suspension will compress, so you want less rebound so that the suspension will re-extend. Conversely, the stiffer you have the compression damping, the stiffer you want the rebound so the the car does not jack itself up over small bumps. It is this relationship that makes shock adjustment so tricky.

There is no 0 point. Rebound damping starts the instant the shock begins to extend.

wanna911

Ah ok, I get it now. I had it in my mind because of the JIC which I assumed increased both when increasing stiffness but going over a bump was torture. I was thinking that since the springs aren't compressing much on the front side the the result engergy would catapault the car higher and then you'd need less rebound so the wheel would return to the pavement quicker, but then the resulting compression could really prop the car up, which makes sense.

Based on this conversation I'm definitely not ready for a 3-way.


Sway bar question now (LOL). Does a stiffer front sway bar allow you to run softer dampening/springs before the tires roll over the outside? I always thought running a stiff front sway in a Porsche would be retarded without adjusting rake angles because it would make the car understeer more.

Sam N

I have JRZ triples and wouldn't mind switching to (Moton) double adjustables. I went from Eibach springs and Bilsteins to these, and it was probably not the most logical progression for me. I get a headache trying to figure out the settings. It also didn't help that I bought them secondhand and have never been disciplined enough to make notations as to the settings. My own fault.

Best of luck with your upgrade.

va122

VR, can you send to me too victor.apostolou@gmail.com

Veloce Raptor

sent

va122

I may have a buyer for your JIC's, would they fit a c4?

wanna911

Yes.