"Normal" ride height
Discussion
Hi Steve,
I have a 96 500 and have just fitted some Nitrons....before fitting the height was as follows:
Drivers Front - 610mm
Drivers Rear - 645mm
Passenger Front - 610mm
Passenger Rear - 660mm
This measurement was taken with someone sat in the drivers seat (15 stone) and from the top of the wheel arch (outside highest top edge) to the ground
hope this helps,
Lig.
I have a 96 500 and have just fitted some Nitrons....before fitting the height was as follows:
Drivers Front - 610mm
Drivers Rear - 645mm
Passenger Front - 610mm
Passenger Rear - 660mm
This measurement was taken with someone sat in the drivers seat (15 stone) and from the top of the wheel arch (outside highest top edge) to the ground
hope this helps,
Lig.
Yep would agree, but for my purposes, on the same car, i.e fitting nitrons and setting the height back the same, this should be OK, agree the body could be well out which is why I am setting back the same and not level with the body. It may give SteveV8s just a ball part figure to compare with??
just trying to assist??
Lig
just trying to assist??
Lig
Best thing to do is get the car corner weighted as this will not only balance the car but also set it up correctly for ride height. It is far better than simply measuring ride heights and trying to get some comparison.
Check the clearances afterwards though as the optimum ride height for balance may not be ideal. This can occur if the wrong/different springs/shocks have been supplied. Don't laugh I heard of someone with exactly this problem last night.
Check the clearances afterwards though as the optimum ride height for balance may not be ideal. This can occur if the wrong/different springs/shocks have been supplied. Don't laugh I heard of someone with exactly this problem last night.
shpub said:
Check the clearances afterwards though as the optimum ride height for balance may not be ideal.
I don't understand what you mean by "the optimum ride height for balance". The ride height and corner weight adjustments can be made independently, so corner weighting won't correct the ride height unless your engineer decides to change them both at the same time. If you adjust the ride height then you also need to adjust the rest of the geometry, so unless this corner weighting exercise is part of a full suspension setup I would expect the ride height to be left alone.
Indeed.
ride height and corner wesights are independaent of each other .. you cna run the car very high or very low and still have the corner weights equal.
likewise you can have a car which is at the correct height but cross-corners are carrying disproportionate loadings ie front left and right rear may have thier platforms wound a long way up, the other two a long way down, car ends up same height as before but the corner weights are miles out.
best thing on a road car is to set the spring platforms the same side to side at a level that gets you the ride height you desire. job done.
ride height and corner wesights are independaent of each other .. you cna run the car very high or very low and still have the corner weights equal.
likewise you can have a car which is at the correct height but cross-corners are carrying disproportionate loadings ie front left and right rear may have thier platforms wound a long way up, the other two a long way down, car ends up same height as before but the corner weights are miles out.
best thing on a road car is to set the spring platforms the same side to side at a level that gets you the ride height you desire. job done.
When you're measuring ride height, it is essential that you measure from the chassis not the body. The body dimensions will vary from car to car and from side to side, and may even vary over time as the body moves on the chassis.
It is also important to establish a flat surface for the measurements. This means getting all four contact patches level to within a quarter of an inch or better. Quarter of an inch difference over the length of a car is imperceptable and you can't just do this by eye, your average 'flat' bit of driveway is actually miles out. However, you can establish a level very easily using a spirit level and a few boards to place under the low corners.
If you had to pack the wheels up to get it level, remember when you measure the chassis height to measure it to the bottom of the tyre and not to the ground.
I agree with Joolz that corner weighting is pretty much a waste of time for a road car, all it is really good for is detecting bent or mismatched components. And obviously you would inspect the new components before fitting to ensure they were the same from side to side.
Setting the ride height by eye can be quite misleading.
For cosmetic reasons people seem to prefer to have the car very low so the wheel fills the arch. Since the normal ride height is a lot higher than this, and since the clearance varies from side to side, it's easy to jump to the conclusion that it is too high and lop sided. If you start 'correcting' it based on this then things get really messed up.
Just set the ride height so the lower wishbones are horizontal and ensure the spring seats are the same position relative to the damper body on both sides. That's all there is to it. You don't need anything more complicated than a ruler and a spirit level, and you certainly don't need thousands of pounds worth of electronic scales and alignment equipment and engineers at £100 an hour to do it for you.
It is also important to establish a flat surface for the measurements. This means getting all four contact patches level to within a quarter of an inch or better. Quarter of an inch difference over the length of a car is imperceptable and you can't just do this by eye, your average 'flat' bit of driveway is actually miles out. However, you can establish a level very easily using a spirit level and a few boards to place under the low corners.
If you had to pack the wheels up to get it level, remember when you measure the chassis height to measure it to the bottom of the tyre and not to the ground.
I agree with Joolz that corner weighting is pretty much a waste of time for a road car, all it is really good for is detecting bent or mismatched components. And obviously you would inspect the new components before fitting to ensure they were the same from side to side.
Setting the ride height by eye can be quite misleading.
For cosmetic reasons people seem to prefer to have the car very low so the wheel fills the arch. Since the normal ride height is a lot higher than this, and since the clearance varies from side to side, it's easy to jump to the conclusion that it is too high and lop sided. If you start 'correcting' it based on this then things get really messed up.
Just set the ride height so the lower wishbones are horizontal and ensure the spring seats are the same position relative to the damper body on both sides. That's all there is to it. You don't need anything more complicated than a ruler and a spirit level, and you certainly don't need thousands of pounds worth of electronic scales and alignment equipment and engineers at £100 an hour to do it for you.
Certainly agree about the problem finding level ground. When you think of it other than an internal floor, nobody deliberately lays a piece of level hard standing. Even a tour of local car parks failed to produce anything. I ended up carefully raking my gravel drive way and placing two boards on it. For the record Height to the chassis rails is set at 12 cm all round.
starmist said:
Or find someone friendly with a warehouse (great when blipping the throttle) or you local tyre centre who may let you use their ramp.
Even better if they have laser alignment... Try buying them lunch just so you can play with settings whilst they eat :-)
Just for info, I toured last summer with an extremely packed boot, so I dilligently set the ride height with the car loaded up. Funnily enough the car was not too unpleasant when unloaded - ride height must have been nearly 7" at the rear. Subsequently I have started setting the car a little on the high side, much greater peace of mind with speed bumps etc..
Dave
>> Edited by spend on Tuesday 29th March 10:52
joospeed said:
Indeed.
ride height and corner wesights are independaent of each other .. you cna run the car very high or very low and still have the corner weights equal.
likewise you can have a car which is at the correct height but cross-corners are carrying disproportionate loadings ie front left and right rear may have thier platforms wound a long way up, the other two a long way down, car ends up same height as before but the corner weights are miles out.
best thing on a road car is to set the spring platforms the same side to side at a level that gets you the ride height you desire. job done.
Cross weight are the important figures as they determine whether the car handles uniformaly through left and right turns. If they are not equal then the car will understeer in one and not in the other. As the method of adjusting the cross weights is by adjusting the ride height then the two are very much interlinked. I agree about static corner weights but I was really refering to cross weight. Should have made it clearer.
While it is possible to have the corner weights equal and different ride heights, this is only measuring static weight which is screwed up as soon as a driver gets in the car. The only way to adjust this is by moving weight. Not really feasible although I do declare myself variable ballast.
Having experienced the difference it makes to a car, there is no way I would go back to simply setting up the car based on ride height alone as I know as soon as I get in it, the balance is going to be screwed up.
It is a bit of compromise as the weight distribution does vary with fuel and whether you have a second passenger in. But these make the same difference setting it on ride height.
In the end, you pays your money and take your choice. It is funny how people buy race/competition spec shock components and then don't bother to set the car up to fully exploit them IMHO. Anyway, try it and you will be amazed at the difference it makes.
www.grmotorsports.com/cornerweight.html has a nice article about this.
steve-v8s said:
Certainly agree about the problem finding level ground. When you think of it other than an internal floor, nobody deliberately lays a piece of level hard standing. Even a tour of local car parks failed to produce anything. I ended up carefully raking my gravel drive way and placing two boards on it. For the record Height to the chassis rails is set at 12 cm all round.
Are you sure its 120 mm,i'm worried now,measured two cars and came up with 142/145mm to the chassis rail.I would be interested to see what some others are measuring.
Well just so happens I have been corner weighting the old 520 and so did some measurements:
No driver With driver
Left 49.2% 46.6%
Right 50.8% 53.4%
Rear 44.7% 46%
Cross 48.9% 50.0%
I then measured the height from the bottom of the spring base plate and bottom of the shock to see what the difference in spring height necessary to get the 50% cross balance.
FL 43mm FR 38mm
RL 120mm RR 125mm
I am running quite hard springs (about twice that of a Griff) so the amount of height adjustment to acheive the same amount of weight transfer is far less than it would be with a softer sprung car. The front and rear springs are different and the same amount of movement gave differing weight transfers. The trick is adjust little by little rather than jack up one end.
The ride height is what it should be according to my suspension design calcs/simulation. I have a slight amount of rake on the car to help with handling so the effective ride heights are not equal front to back. Not much in it but it is enough.
No driver With driver
Left 49.2% 46.6%
Right 50.8% 53.4%
Rear 44.7% 46%
Cross 48.9% 50.0%
I then measured the height from the bottom of the spring base plate and bottom of the shock to see what the difference in spring height necessary to get the 50% cross balance.
FL 43mm FR 38mm
RL 120mm RR 125mm
I am running quite hard springs (about twice that of a Griff) so the amount of height adjustment to acheive the same amount of weight transfer is far less than it would be with a softer sprung car. The front and rear springs are different and the same amount of movement gave differing weight transfers. The trick is adjust little by little rather than jack up one end.
The ride height is what it should be according to my suspension design calcs/simulation. I have a slight amount of rake on the car to help with handling so the effective ride heights are not equal front to back. Not much in it but it is enough.
GreenV8S said:
Check the clearances afterwards though as the optimum ride height for balance may not be ideal.
I don't understand what you mean by "the optimum ride height for balance". The ride height and corner weight adjustments can be made independently, so corner weighting won't correct the ride height unless your engineer decides to change them both at the same time. If you adjust the ride height then you also need to adjust the rest of the geometry, so unless this corner weighting exercise is part of a full suspension setup I would expect the ride height to be left alone.
OK. Lets not call the spring base the ride height adjuster as in reality it is the spring preload adjuster. By increasing this preload, the ride height is also changed and so this enables the ride height to be adjusted by changing the spring preload. The ride height could also be adjusted by changing the spring length and/or the spring rate. A softer spring of the same length would compress more and lower the ride height. This is why heavier springs either require a shorter length or adjusterble spring preload to compensate.
As for changing the ride height and geometry chceking. Fully agree but that is true whether you corner weight or measure with a ruler as the ride height difference will affect the geometry in the same way. How many people bother to do this anyway?
The spring preload also effects the weight distribution and car balance. Get the balance right and this is more to do with cross weighting balance rather than the static L/r F/R ones and the ride height will come out based on the spring spec. It should have the right length after compression for the ride height. If it doesn't then there is an issue. The car might ride too high or too low. T
The problem I was referring to was with a car that had new shocks and springs where the car was setup for a particular rideheight which made sense. However on a track day, the balance was all wrong and the tyre ended up rubbing on the wheel arch.
Now the ride height measured statically was OK and acceptable. If a cross weighting had been done it would probably have identified that the balance was way out and that something was not right. I suspect the wrong springs or the ride height selected was not the appropriate one to get the balance.
I've done a lot of setups this way now and find that it is a really good way of getting the best out of the car. I've done it starting with a ride height and with the spring adjuster on the bottom and worked my way from there.
I more or less agree with your description Steve, but you still seem to be implying that ride height affects the corner weights and weight distribution. Obviously it doesn't, unless you're moving on to talk about roll centers (which I don't think you are).
The only way to affect the static front/rear or left/right weight distribution of the car as a whole is to move weight within the car so as to move the center of gravity. Changing the ride height, or adjusting the corner weights, makes no difference to the static weight distribution of the car.
The spring seat adjusters can be used to adjust the ride height and to adjust the corner weights. It is possible to adjust the corner weights without adjusting the ride height, and vice versa.
If you send the car in to have the corner weights set, you would not normally expect to have the ride height changed unless the car was in for a whole suspension setup. Similarly, if the ride height is wrong it is possible to adjust it without disturbing the corner weights.
I hope your understanding is the same, but I just wanted to avoid potentially misleading anyone.
The only way to affect the static front/rear or left/right weight distribution of the car as a whole is to move weight within the car so as to move the center of gravity. Changing the ride height, or adjusting the corner weights, makes no difference to the static weight distribution of the car.
The spring seat adjusters can be used to adjust the ride height and to adjust the corner weights. It is possible to adjust the corner weights without adjusting the ride height, and vice versa.
If you send the car in to have the corner weights set, you would not normally expect to have the ride height changed unless the car was in for a whole suspension setup. Similarly, if the ride height is wrong it is possible to adjust it without disturbing the corner weights.
I hope your understanding is the same, but I just wanted to avoid potentially misleading anyone.
Hi GreenV8s and SHpub,
I am getting really confused here......Lets talk yes o answer.....
I have just fitted Nitrons and set the height of the car back to what it was before (or as near as) with both front shocks the same height and both rear shocks the same height.
1. Would you recommend me having the car corner weighted with me in it - as i understand it this will involve the spring seats being at different levels. The guy i bought the shocks from said deffo, a guy who sells Tivs and races single seaters told me he could do it but he didnt think it was worth it, because of center of gravity, obviously worth it on a SS. Just keep the front two and the rear two shocks the same height was his advice?
2. should i leave alone as the car will now be level (well as level as it was before and surely the chassis 'should' be level as it was designed to have static shocks on??
Cheers in advance Lig.
I am getting really confused here......Lets talk yes o answer.....
I have just fitted Nitrons and set the height of the car back to what it was before (or as near as) with both front shocks the same height and both rear shocks the same height.
1. Would you recommend me having the car corner weighted with me in it - as i understand it this will involve the spring seats being at different levels. The guy i bought the shocks from said deffo, a guy who sells Tivs and races single seaters told me he could do it but he didnt think it was worth it, because of center of gravity, obviously worth it on a SS. Just keep the front two and the rear two shocks the same height was his advice?
2. should i leave alone as the car will now be level (well as level as it was before and surely the chassis 'should' be level as it was designed to have static shocks on??
Cheers in advance Lig.
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