Help me understand 'roll center'

^^ Hmm, yeah I get what you're saying. Thanks!

 

OK, got my panhard bar move up just above the pumpkin, roll center up about 5 inches from where it was. Then I got sidetracked installing a parking brake on the pinion, something I've been wanting to do for a long time. So far in my highly scientific testing, dong 1st gear figure 8s, it does have less body roll. Haven't hit any bumps yet.

I've been trying to install a front sway bar (Corvair IFS, highly modified) for some time but haven't been able to find the wiggle room, that would help too I'm sure. The one thing that might work is to clamp one to the strut rods, dunno if that's ever been done or if it would work. That would be the lower bar in this photo

Nothing on this heap is ever easy...

 

There are a lot of stuff on the net which explains suspension geometry. There is also an enormous amount of misinformation out there. As an example, this article will give you a start. http://www.motoiq.com/MagazineArtic...in-the-geometry-part-one-the-roll-center.aspx
The difference in a rod that is set up well is unbelievable. They damn near feel like they are on rails. One that is not set up well can be downright dangerous. Think this through and do what you are comfortable with. By all means do your research.

 

Steve Smith auto sport books are great at explaining this too. Hard to see the pinion mount from pic of my "A" mod but reguardless of which side it's mounted on, to me personally the adjustments at the pinion even slight ones can drastically alter roll effects of the car "hot rod or race car". compared to adjustments at the chassis end of the panhard. One can read so much it makes your head hurt but trial & error of testing will eventually yield the results your looking for....... I hope. Good advice would be to establish a baseline, make one adjustment at a time , evaluate how it felt, if crappy undo it , back to baseline go again. Need to get weight, ride heights, pinion angles, etc. Set then begin process of test n' tune. Lots of great advice on this thread so far. Even if some of us occasionally ,"Saturday nights" like to go fast & turn left. Good luck! Flux

 

Ain't that the truth, a buncha rocket scientist on this board, and I mean that in the most positive way! ROCKet ON!
You guys amaze me............viva la H.A.M.B.!

 

Did more panhard bar tuning yesterday, really impressed with the decrease in body roll. After decades of fiddling with engines it's kinda fun gaining some chassis knowledge. Thanks for all the input fellas.

 

Go look at the higher end alcohol dirt track stock car chassis. You want to see a whole wild set of chassis adjustments! Different length pan hard bars, left rear wheel pulls forward under acceleration. valve to shut off right front brake etc. Those guys make changes during the night of racing. according to how the dirt is behaving.

 

Me too, on my coil overs I have 5 sets of holes on the top cross member to adjust stiffness, another 5 vertical on the bottom mounts for ride height and another similar set for the panhard bar. I've been under there so many times I should put a pillow down. I'd snap a picture but it's embarrassingly ugly, haven't gotten around to painting any of it.