Race car suspension Class

[Savem c10]

So there two types of roll center geometry that I know of. Most common is kinetic roll center does work. But over the last year I’ve been working with jacking force geometry on and off and found it works better than a kinetic based roll center geometry. Does anyone on here know of racers using jacking force geometry and have knowledge on or know of any literature to read on it . Rm… Mender ??

 

[Ranger Mike]

By kinetic i take it you are using the automation mode on software like Performance Trends that show Roll center migration on roll and dive, right? Is the jacking force function on some other software?

 

[Savem c10]

By kinetic i take it you are using the automation mode on software like Performance Trends that show Roll center migration on roll and dive, right? Is the jacking force function on some other software?

I don’t have any computer software as of yet iv always mapped roll centers out life size on paper. I have no way of knowing migration . Based on recommended starting points for roll centers is what I’ve done. I do not know if there is a function for that type of geometry u would know better as u have the software.

 

[alpharomeofifetwo]

Tie down shock keeps weight on rt ft forever .

Finally got to run Saturday night.

Through processes of elimination, I firmly believe a shock change is due.

Shop work
Double checked all chassis mounts/measurements to make sure everything was square. Ran rear roll steer numbers and got about a 1/4” max trail in dynamic on RR
0 lead/trail on LR. Rescaled car. Stiffened up springs

Track/chassis adjustments
We stiffened up the front 200lbs each spring, stiffened LR to a 20” 125#, softened up RR to a 200, moved LR in 1”, moved RR out 1” via offsets, moved lead lower 8-10”, tightened chain on LR RR and LF, cranked cross / bite in it. Pulled a 50lbs lead chunk off the right side low. No matter the change, we still got the same results.

Race day notes
Bumped those tire air pressures up to 17-22 psi, Couldn’t get an accurate temp readout due to the infield being very wet from rain during the week. But we burnt the rr up and every other tire looked exactly the same as it went on the track, No feathering on any tire except RR. I think we had it set to 22psi and noticed it did wear significantly more across the center treads so might’ve been a tad much on air. Started the race with 1/4” of reverse stagger just to try a last ditch effort

Car had “the usual” handling; great getting in, lacking drive mid off… even with all the “positive” changes. I’m chalking this whole issue up to the shock package and shipping them off today to be redone like I mentioned in a prior post .

 

[Ranger Mike]

Right rear is worn out because it is not hooked up. Still loose off. Why? front springs too soft plus you have no arb. Good news is the car is going In ok. No traction corner off.