First time ever corner weighting a car. This is from my 1989 BMW 325ix track car (just for fun, no rules to conform to). Not sure I can move much weight around, but I do have a coilover suspension that I could adjust to move the cross weights a little?
LF 657 RF 720 LR 577 RR 485 Total 2438 Front 56.5% Rear 43.5% Left side 50.5% Right side 49.5% RF/LR Cross 53.2% LF/RR Cross 46.8%
Let me know what you think.......
James Reeser Watertown, SD
Holy cow you're almost local! I'm from Sioux Falls and at school in Vermillion. Just thought I'd point that out.
Carry on...
get the cross to 50.0%
that's quite light for an ix.
Yup, try to even those cross weights. Don't bother trying to move weight forward or sideways, it won't unless you're physically moving stuff (like the battery) around. I'd recommend moving the LF and RR up by a certain amount (say, 2 turns) and the RF/LR down by the same. Then see how much the change was, and try again.
By moving all four perches like that, you'll keep the car sitting flat and level. Move just one or two, and you can end up with it all cockeyed.
Is that with or without a driver?
Without.....I'll try again with tomorrow.
Use ballast to simulate driver weight.
If your cross-weights are uneven the car will corner differently left versus right. As in, understeer turning left and oversteering turning right. You'll pull your hair out attempting to tune your chassis if your cross-weights are messed up.
Also, absolutely ensure that you are not so low that you can bottom the suspension. Bottoming suspension basically eliminates grip at that end of the car. Recipe for instant off.
David
O.K. Tried it with me sitting in the driver's seat and my boy wrote the #'s down. LF 723, RF 743, LR 651, RR 510, Total 2627 Front/Rear is better @ 55.8F/44.2R Cross is the same @53.1/46.9, Left side 52.3%, Right side 47.7%
I will make some adjustments to the coilover heights (like Keith suggested) in a day or so when I have time & report back.
Thanks to everyone for the feedback!!
James
Keith wrote: Yup, try to even those cross weights. Don't bother trying to move weight forward or sideways, it won't unless you're physically moving stuff (like the battery) around. I'd recommend moving the LF and RR up by a certain amount (say, 2 turns) and the RF/LR down by the same. Then see how much the change was, and try again. By moving all four perches like that, you'll keep the car sitting flat and level. Move just one or two, and you can end up with it all cockeyed.
Keith, You rock the house! After following your advice, I am now at 50.5% cross weight!! Thanks again!
James
325ix track car. That's just cool.
Oh yeah, measure your ride height while loaded (rocker pinch weld to floor). This is an easy way to double check your shock travel & make sure your not bottomed out in a corner. You should be able to have a 4 corner even ride height & 50% cross with a little tedious effort.
Also, make sure you are at race weight with fuel. I would always align a car with the minimum fuel that it could run (and not slosh out of the pickup) so the car was perfectly balanced at the end of the race - The car should get faster as fuel drops. Enduro cars are usually aligned with 1/2 tank so its sweet spot is in the middle & when the car is getting tail happy its time to bring it in ;)
Kendall
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