Corner balancing strategies
09-22-2018, 03:54 PM
#21
09-22-2018, 11:36 PM
#23
Drifting
it is a vette and i have no scales. i was asking what one turn does, because i dish out $100 every time i get i weighted.
according to the calculator im 8 kg off, better than i thought, but he sais he doesnt believe in cross weight, he does something else, cws equalize nevertheless in the end. i guess because the car is so close.
according to the calculator im 8 kg off, better than i thought, but he sais he doesnt believe in cross weight, he does something else, cws equalize nevertheless in the end. i guess because the car is so close.
Last edited by romandian; 09-22-2018 at 11:59 PM.
09-23-2018, 09:23 AM
#24
I can't remember how much 1 turn does. You need to decide whether you want to raise to low corners or lower the high corners. For 8 KG, or about 17 lbs I would do one turn on each of the 2 corners you decide to change Remember to disconnect and adjust the sway bar end links to remove any preload. Next time I have my car on scales, and it may be a while because I just did it a week ago, I will see what one turn does.
09-23-2018, 10:42 AM
#25
it is a vette and i have no scales. i was asking what one turn does, because i dish out $100 every time i get i weighted.
according to the calculator im 8 kg off, better than i thought, but he sais he doesnt believe in cross weight, he does something else, cws equalize nevertheless in the end. i guess because the car is so close.
according to the calculator im 8 kg off, better than i thought, but he sais he doesnt believe in cross weight, he does something else, cws equalize nevertheless in the end. i guess because the car is so close.
10-01-2018, 07:14 PM
#26
50/50 cross first, then look at your front/rear ratios on each side. Unless those are SERIOUSLY out of whack, 50/50 is your goal. If your side bias's (front/rear) are more than about 3% off, then you need to go on a diet, or move some weight to the right side/rear end.
Example:
lf 750 rf 650
lf 650 rr 550
cross weights 50/50, left side 1.15, right side 1.18 (2.6% difference). Car will have more relative front grip on right handers, and more relative rear grip on left handers, but overall 50/50 is best.
Example:
lf 750 rf 650
lf 650 rr 550
cross weights 50/50, left side 1.15, right side 1.18 (2.6% difference). Car will have more relative front grip on right handers, and more relative rear grip on left handers, but overall 50/50 is best.
10-02-2018, 12:42 PM
#27
Melting Slicks
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Can't remember if I mentioned this before:
Make sure the F wheels are pointed straight ahead (even F toe, side to side)
The caster causes noticeable weight transfer when the wheels are turned.
Make sure the F wheels are pointed straight ahead (even F toe, side to side)
The caster causes noticeable weight transfer when the wheels are turned.
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romandian (10-02-2018)
10-02-2018, 02:36 PM
#28
One of the thinfs we did when I worked for a formula car team was we lowered the tire pressires to 10-15lbs to even out the weight on each scale pad.
This helped even out caster differences and what not
This helped even out caster differences and what not
10-02-2018, 09:08 PM
#29
Yeah but if you are corner balancing you want to scale at hot pressures.
10-03-2018, 12:34 AM
#30
Pro
Another fun fact: It’s well known that the fuel in a corvette is drawn from the passenger’s tank first and then the driver’s side tank next when running. However, when the car is at rest (and by that I mean turned off), the fuel in the drivers tank will syphon back into the passenger’s side tank and reach equilibrium. So if you’re like me and you corner balance with 1/2 fuel, if you don’t run the car first, the fuel will be equally distributed between left and right tanks rather than a full left tank and an empty right tank.
Last winter I ripped out the factory wiring in my C5. I have two fuel gauges, one for each tank. When you start the car after it’s been sitting, the levels are equal. When the car is running, the fuel gets transferred from the passenger’s side to driver’s side as you’d expect.
Anyway, this makes an (arguably small) difference in your corner weights.
Last edited by Grabbed_Crow_Mobe; 10-03-2018 at 12:35 AM.
10-03-2018, 10:20 PM
#31
on paper - yes.
what youre really trying to find out how ypur car is balanced.
On the track there are a bunch of other things going on, including wheels spinning - which is not the case at the shop.
Try it next time you weigh your car. Once with hot pressures and once at 15psi.
See what happens.
10-03-2018, 10:48 PM
#32
I truly do not understand why going 15psi does anything. What does that represent? I'm happy to learn. You are adjusting coil spring heights to gain a 50% cross. The tire is a spring and it has a spring rate. The tire pressure controls the tire rate. Therefore you have to pick a reasonable tire pressure that represents the driven condition which means hot pressures. It is for a similar reason you use 1/2 the fuel load.
10-04-2018, 01:04 PM
#35
Drifting
It will and so will the sway bars if they are not disconnected. I you can't imagine the change, try scaling a car yourself and try the different pressures and see what happens to the cross weight. Even opening a door to raising the hood will make a difference. Also, how you place the weights in the driver's seat will make a difference.
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Nowanker (10-25-2018)
10-04-2018, 02:34 PM
#36
Pro
Although, if/when they are different, I'm not sure what I'm going to do with that information or how I will change my approach...
10-04-2018, 04:13 PM
#37
Melting Slicks
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It will and so will the sway bars if they are not disconnected. I you can't imagine the change, try scaling a car yourself and try the different pressures and see what happens to the cross weight. Even opening a door to raising the hood will make a difference. Also, how you place the weights in the driver's seat will make a difference.
Skeptical of a difference from changing tire pressures though, as long as they're all kept even. Next car I scale I'll check! Think the concept of lowering them dramatically to account for possible rim runout is sorta sketchy...
Keeping in mind that these are 3,000 pound+ porkers, and I doubt even Alain Prost could feel 20lbs of 'wrong'!
10-04-2018, 08:31 PM
#38
We use hot tire pressure to simulate what the chassis will see at a static point. We use tire pressure because pressure controls the height of the tire as a spring just like the spring collar on coilovers or adjusters on our transverse leafsprings. Deflating to non-driven pressures (15psi) or using any pressure other than hot pressures you have no idea of CG height, rake, ride height, front/rear percentage, real corner weights, or the real effects of real weight moved around or ballast added.
I mount and balance my own tires on wheels If the wheel is off 0.040" you would need about 4 oz of weight to balance the wheel/tire. Does anyone have that much weight on their wheels? 0.40" is where you throw the wheels away! Wheel tire discrepancy is not an issue especially on a 3000+lb car without monoball suspension
I mount and balance my own tires on wheels If the wheel is off 0.040" you would need about 4 oz of weight to balance the wheel/tire. Does anyone have that much weight on their wheels? 0.40" is where you throw the wheels away! Wheel tire discrepancy is not an issue especially on a 3000+lb car without monoball suspension
