Question: Corner Weight
Created by: Rosebud
Orig. Posting Date | User Name | Edit Date |
Nov 1, 2018 04:59AM | CooperTune | |
Nov 1, 2018 01:26AM | Alex | |
Oct 31, 2018 07:23PM | Rosebud | |
Oct 31, 2018 05:38AM | Dan Moffet | |
Oct 30, 2018 06:39AM | Alex | |
Oct 28, 2018 05:21AM | CooperTune | |
Oct 27, 2018 12:00PM | JohninCM | |
Oct 27, 2018 09:13AM | Rosebud | Edited: Oct 27, 2018 12:41PM |
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That's the beauty of fully adjustable suspension. While it gives a chance to get things correct it also allows for so many incorrect settings. As I think I mentioned we get the ride height then adjust all the other settings. Placing rules at all four corners and working Hi Los at all four corners up or down as required ride and weight can be close to correct. Since most Vintage cars have two bolt per side front subs I made up four long T handle allen wrenches so we can adjust each corner without moving wrenches. There is so much more to it than just turning wrenches. After each change, I like to roll off and back on the scales maybe even bounce it a little. If you have to jack the car up to adjust ride chances are you will never get it right with a rubber spring car. With the race cars, we complete adjustments load the car on the trailer secured with chains so as not to load the suspension and drive it down the roughest roads close by. Bring it back and recheck all settings.
I was finding that after a full day of suspension adjusting then trailering to the track I'd arrive at track and setting were no longer where I left them. It is possible to get repeatable settings just have to be serious about what you are doing. Steve (CTR)
I was finding that after a full day of suspension adjusting then trailering to the track I'd arrive at track and setting were no longer where I left them. It is possible to get repeatable settings just have to be serious about what you are doing. Steve (CTR)
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Having spent hours corner weighting Gertie, yes, you've upset it quite a lot.
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Quote:
Originally Posted by Dan Moffet
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Quote:
Originally Posted by Rosebud
- I had my car corner weighed a few months ago. Ever since, I noticed the right rear seemed to be sagging a bit. A tape measure confirmed that the right rear was about ½” lower than the other three corners.
It was about that time that I begin scraping the right rear fender well whenever I hit I significant bump in the road. It is my understanding that aside from moving ballast around to equalize the weight in all four corners, ride height can be adjusted to achieve weight balance. I raised the right rear corner ½” inch to achieve symmetry and the scraping stopped. My question is: have I undone my corner weighing? I think I know the answer, but for the sake of my wheel arches, I think I’ll leave it as is. Any thoughts?
EDIT If I did transfer weight by raising the RR, where did the weight go, LF?
To visualize weight distribution, think of a table that wobbles a bit. That's because all four legs aren't touching the floor equally. If you shim the short leg just right, the table will sit evenly. If you do too much, more weight is carried on that leg and the diagonally opposite one and the table rocks on the other 2 corners.
In a Mini it gets more complicated because the front end is heavier than the rear (the percentage varies depending on the model). Add to that the live load - the driver, any passengers, your toolkit in the boot and the amount of fuel on board (which is a variable).
Not having access to proper weight measuring equipment, when I changed my springs, I got my car leveled and balanced adequately for road use by jacking one end up in the centre so it could pivot freely left-to-right and adjusting the other end level, then switched ends. Not very scientific but better than what it received at the assembly line.
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"Hang on a minute lads....I've got a great idea."
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What Steve said.
If you're aiming for proper cornerweights you have to ignore what the rideheight is. By jacking up that corner by half an inch you've massively loaded that wheel and added weight to the diagonally opposite one while unloading the other two. It's also not as simple as raising all four corners by half an inch as you'll throw the steering geometry out by doing so.
I'd suggest re-doing the cornerweighting and geometry using the corner you wound up as the low point - everything else on the car needs to revolve around that.
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Everything you change changes everything else. I have electronic scales, turntables, Dunlop optical toe as well as caster/camber gauge. I was lucky enough to find some (4) 5/8 thick aluminum disc the correct dia to replace the wheels and tires. I drilled two for a center hole and bolt pattern and two for just the bolt pattern for the rear. I also have a couple of digital angle finders for quick checks. With two steel studs clamped to the front plates set at zero, I can locate the rears and adjust each side in reference to the front.
It takes three of us hours to properly align and corner weight a fully adjustable car. Once we have a correct weight and build driver he can read the paper or a magazine.
In answer to your question pumping 1/2 inch of ride to one wheel has made a large change in corner weight. You have added weight to the corner you raised and it's opposite corner and shed weight off the other two corners. You can't get perfect corner weights due to driver location. Once we have ride height, caster/camber and toe we work on corners. With rulers at the four measure points, we chase weight keeping ride height in mind. We try and get balance across the front and allow the rears to take care of themselves. Steve (CTR)
It takes three of us hours to properly align and corner weight a fully adjustable car. Once we have a correct weight and build driver he can read the paper or a magazine.
In answer to your question pumping 1/2 inch of ride to one wheel has made a large change in corner weight. You have added weight to the corner you raised and it's opposite corner and shed weight off the other two corners. You can't get perfect corner weights due to driver location. Once we have ride height, caster/camber and toe we work on corners. With rulers at the four measure points, we chase weight keeping ride height in mind. We try and get balance across the front and allow the rears to take care of themselves. Steve (CTR)
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Yes, raising the right rear will change the corner weight distribution. Most of the change will be found at the LF however both RF and LR could show a change also. When the corner weight was getting adjusted did weight get added to simulate a driver behind the wheel (either a genuine human or weight bags)? Very important to include the drivers weight on a car that is roughly 1,400lbs.
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- I had my car corner weighed a few months ago. Ever since, I noticed the right rear seemed to be sagging a bit. A tape measure confirmed that the right rear was about ½” lower than the other three corners.
It was about that time that I begin scraping the right rear fender well whenever I hit I significant bump in the road. It is my understanding that aside from moving ballast around to equalize the weight in all four corners, ride height can be adjusted to achieve weight balance. I raised the right rear corner ½” inch to achieve symmetry and the scraping stopped. My question is: have I undone my corner weighing? I think I know the answer, but for the sake of my wheel arches, I think I’ll leave it as is. Any thoughts?
EDIT If I did transfer weight by raising the RR, where did the weight go, LF?