Has anyone had thier car Corner weighted ? If so could you post up your results ? i.e. before and after weights!!
Corner weights
- Thread starter Laurence Gibbs
- Start date
SimonExtreme
New member
My car was corner weighted after the suspension was renewed (struts, springs, wishbones etc). They played around with both ride height and corner weighting. It's not really possible to give a before and after because there is no before. If I read the report correctly, the final figures achieved are as follows.
Ride height F 128/128
R 233/235
Corner weights F 530/530
R 820/860
Interestingly, they checked the settings a few times over a couple of days and after a few drives as it took a while to settle the new suspension. At one time they found the corner weights to be
F 530/585
R 850/850
This was deamed as totally unsatisfactory.
I hope that is of some use.
Ride height F 128/128
R 233/235
Corner weights F 530/530
R 820/860
Interestingly, they checked the settings a few times over a couple of days and after a few drives as it took a while to settle the new suspension. At one time they found the corner weights to be
F 530/585
R 850/850
This was deamed as totally unsatisfactory.
I hope that is of some use.
Thanks simon that's exactly the sort of info I wanted[
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one thing with your figures. I guess the actual finished figure is correct but the "interim" figure does'nt make sense unless they actually moved weight around the car. For instance
front left and rear left are a constant relationship i.e. the totals always remain the same as are front right rear right and also front axle and rear axle TOTALS stay the same. In your example the before measure for FL+RL = 530 + 860=1390 and your final figures are 585 + 850 = 1435 this is afaik not possible, the axle figures don't add up either RR+RL before = 860+820 =1680 after 850 + 850 = 1700 I would guess the "interim" figure is due as you mentioned to some settlement in the new suspension and to be expected(though how you make extra weight , bu**?red if i know). Tolerance, I believe Porsche quote less than 40 Lbs difference per corner although a good corner weight should get a lot closer than that.
front left and rear left are a constant relationship i.e. the totals always remain the same as are front right rear right and also front axle and rear axle TOTALS stay the same. In your example the before measure for FL+RL = 530 + 860=1390 and your final figures are 585 + 850 = 1435 this is afaik not possible, the axle figures don't add up either RR+RL before = 860+820 =1680 after 850 + 850 = 1700 I would guess the "interim" figure is due as you mentioned to some settlement in the new suspension and to be expected(though how you make extra weight , bu**?red if i know). Tolerance, I believe Porsche quote less than 40 Lbs difference per corner although a good corner weight should get a lot closer than that.
SimonExtreme
New member
Laurence
Having read the history a bit more, I think there is another reason for the anomoly. It seems that when they first started the corner weighting, the n/s/f collar was on its lowest setting. This meant they had to adjust all of the collars to get them into a situation that they could then make whatever adjustments needed.
I have been trying to do some more research into this, as when I raced we used to be able to get everything spot on. The f=difference of 40lbs across the rear is "interesting" and I note that it was decided to get the front right and live with the differences at the rear. It seems intuitive that this is the right thing to do but cannot find any references to this in any article or book. I need to dig further but having had a little play on the road today, I cannot feel a difference between turn in and handling at sensible speeds.
Having read the history a bit more, I think there is another reason for the anomoly. It seems that when they first started the corner weighting, the n/s/f collar was on its lowest setting. This meant they had to adjust all of the collars to get them into a situation that they could then make whatever adjustments needed.
I have been trying to do some more research into this, as when I raced we used to be able to get everything spot on. The f=difference of 40lbs across the rear is "interesting" and I note that it was decided to get the front right and live with the differences at the rear. It seems intuitive that this is the right thing to do but cannot find any references to this in any article or book. I need to dig further but having had a little play on the road today, I cannot feel a difference between turn in and handling at sensible speeds.
Parr did mine last year and weighed me as the driver surely that is the correct way...............
yep sure is Des.
Thanks Tony more useful info. Dont think you could get a great deal better than the figures you have. The ideal weight is 251 241
406 388
So not worth the sweat. I have been playing with a diy scale kit similar to the www.tgsi.com/scales.html set (only i have fabbed it myself) my weights uncorrected are
200 176
312 328
I don't think for one minute that my car can be 200kilo's lighter so i guess that's an error in my scales (as they need a little more setup time) but the figures seem to be "in scale" as they are all out by 10 kilos or there abouts. I will post more up when i get the chance to experiment a bit more. Did your car have half a tank of gas too? A cage too? cup pipe or standard? your weight (if you don't mind me asking?)i'm 69 kilos ish.
406 388
So not worth the sweat. I have been playing with a diy scale kit similar to the www.tgsi.com/scales.html set (only i have fabbed it myself) my weights uncorrected are
200 176
312 328
I don't think for one minute that my car can be 200kilo's lighter so i guess that's an error in my scales (as they need a little more setup time) but the figures seem to be "in scale" as they are all out by 10 kilos or there abouts. I will post more up when i get the chance to experiment a bit more. Did your car have half a tank of gas too? A cage too? cup pipe or standard? your weight (if you don't mind me asking?)i'm 69 kilos ish.
Melv, your right up to a point. I am only doing track days too but I want my car to handle in a predictable way and handle sweetly this is not about better lap times but having a sweetly handling car, although probably it's the net result (a bonus). The idea of corner balancing the car is to ensure the car is carrying it weight evenly accross it's suspension. The best analogy is the four legged stool, if the stool has equal weight all legs will be firmly on the ground if the weght is shifted or one of the legs is slightly shorter the stool will rock an be unstable. Porsche quote 20kgs tolerance across each side and if your car runs above this then handling will suffer. Yes having a passenger in the car will upset this difference but if the car is out to start with it will only upset it more, likewise the change in fuel. Porsche quote corner balance for thier standard road cars not just for race cars. It's in some ways as fundamental as toe and camber. A car carrying too much weight on it's drivers side front (lhd) will have a tyre that is overloaded on that side and a tyre that is under used on the other. The net result is understeer and and uneven tyre wear. regardless of how spot on your toe camber and caster are ! It's a deep subject and i've just scrapped the top of it here. try www.elephantracing.com/cornerbalance.htm for more.
SimonExtreme
New member
Couldn't agree with laurence more. Having the car correctly set up is just as important for trackdays as it is for racing, maybe even more so. In the course of a single trackday, you will be doing far more laps than at an average race meet. Here are just some of the benefits.
1. Having the car set up properly reduces running costs. Tyres last longer and there is less stress on suspension components.
2. The car is easier to drive.
3. The car is more predictable in its handling characteristics.
All told, a properly set up car is nicer and safer to drive.
1. Having the car set up properly reduces running costs. Tyres last longer and there is less stress on suspension components.
2. The car is easier to drive.
3. The car is more predictable in its handling characteristics.
All told, a properly set up car is nicer and safer to drive.
Absolutely right Laurence could not agree more what would Herr Melvin Fuherecuppenwaggen know![8D]
Laurence,
Car had half a tank of fuel, no cage, cup pipe and cat in place at that stage - wish I was 69 kilo's - 80 and rising I'm afraid (even without the turkey Yoda!).
I do agree with your later comments I feel it is definitely worth it - it's a lot to do with confidence and predictability. Currently I'm only doing very occasional sprints an even more occasional track days.
I may be talking complete rubbish but it seems to me that when a car is stiffly sprung then corner weighting has more impact than on a softly sprung car.
Tony
Car had half a tank of fuel, no cage, cup pipe and cat in place at that stage - wish I was 69 kilo's - 80 and rising I'm afraid (even without the turkey Yoda!).
I do agree with your later comments I feel it is definitely worth it - it's a lot to do with confidence and predictability. Currently I'm only doing very occasional sprints an even more occasional track days.
I may be talking complete rubbish but it seems to me that when a car is stiffly sprung then corner weighting has more impact than on a softly sprung car.
Tony
The scales system i'm using appears to read light , but i suspect the percentages still work. I have some pic's that i will download at some point. I have made a slight adjustment and am now going through the rest of the alignment in true diy fashion. Will be intresting to see if it has made a difference. I dont think i will have the alignment spot on for North Weald. But we shall see.
Well north weald revealed a car with more understeer, rather than less as I had hoped. But I am still learning an awful lot and I did not expect the very small adjustment to cure the problem. I expect this process will lead to some replacement parts eventually. What I would like to do is make an informed decision on what parts to replace! Here are some pic's of the scale system and a shot of my level across the scales.
and some more
a few more
This one shows my strut on the drivers (lhd) side.
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