Ride Height

[billybradshaw]

Evening all,

I'm getting a little confuddled with setting the ride height and I apologise in advance for the waffle below:

As I'm starting from scratch after fitting new dampers, I've put the front of the car on wooden blocks located at the out riggers. So in effect the front is set at 155mm.

Going to the rear of the car I set about adjusting the off side. I got the chassis (out-rigger corner)to 172mm and this equates to 53mm measured between the locking ring and the end of the threaded portion of the damper body. Also floor to highest part of wheel arch was measured at 684mm

Going on to the near side I wound up the collar to 45mm and decided to check the height out of curiosity. I was rather surprised to see that the outrigger height was 183mm and the wheel arch was 692mm

So my question is, despite the collar being wound up less on the nearside, why would the ride height be higher on this side??? I've checked tyre pressures and these are equal.

The relationship between outrigger and wheel arch from side to side is pretty good with just a 3mm difference. So I'm left thinking that either a) the whole of the rear end is twisted or b) it's a simple case of the spring rates being mismatched or c) I'm a kn*b and I should just get on with fine adjustments to get the heights equal and ignore the fact that the collars are in different places.

Any thoughts folks?

Ta

[pmessling]

Best off setting a good average height on the four corners. Drive it for a bit to let the springs settle then readjust them to where you want them.

I tried what your doing measure Spring seat etc but just doesn't work

[billybradshaw]

pmessling said:

Best off setting a good average height on the four corners. Drive it for a bit to let the springs settle then readjust them to where you want them.

I tried what your doing measure Spring seat etc but just doesn't work

Thanks Peter,

So I shouldn't get overly concerned about the damper spring platform being in different places? I simply need to get the chassis to the correct height on all four corners? I've just got it in my mind that the more the collar is wound up the 'stiffness' on that corner will increase and if it's different from the other side it will really upset the handling.

Ta

Ian

[Jhonno]

billybradshaw said:

pmessling said:

Best off setting a good average height on the four corners. Drive it for a bit to let the springs settle then readjust them to where you want them.

I tried what your doing measure Spring seat etc but just doesn't work

Thanks Peter,

So I shouldn't get overly concerned about the damper spring platform being in different places? I simply need to get the chassis to the correct height on all four corners? I've just got it in my mind that the more the collar is wound up the 'stiffness' on that corner will increase and if it's different from the other side it will really upset the handling.

Ta

Ian

Will only be an issue if your springs are progressive..

[billybradshaw]

Jhonno said:

billybradshaw said:

pmessling said:

Best off setting a good average height on the four corners. Drive it for a bit to let the springs settle then readjust them to where you want them.

I tried what your doing measure Spring seat etc but just doesn't work

Thanks Peter,

So I shouldn't get overly concerned about the damper spring platform being in different places? I simply need to get the chassis to the correct height on all four corners? I've just got it in my mind that the more the collar is wound up the 'stiffness' on that corner will increase and if it's different from the other side it will really upset the handling.

Ta

Ian

Will only be an issue if your springs are progressive..

Right OK good, sounds like I need to brush up on my 'spring theory' and not to be worried about the different positions of the spring platforms.

Ta

Ian

[Byker28i]

155mm and 172mm seems quite high. Is this the measurement from outrigger corner to floor?
I think mine are 120mm front, 130mm rear and mine seems to sit slightly higher than many others

[Jhonno]

Byker28i said:

155mm and 172mm seems quite high. Is this the measurement from outrigger corner to floor?
I think mine are 120mm front, 130mm rear and mine seems to sit slightly higher than many others

That as well..

I run mine a bit lower than standard. Just because that is how I like it really.

[billybradshaw]

Jhonno said:

Byker28i said:

155mm and 172mm seems quite high. Is this the measurement from outrigger corner to floor?
I think mine are 120mm front, 130mm rear and mine seems to sit slightly higher than many others

That as well..

I run mine a bit lower than standard. Just because that is how I like it really.

There are so many views of ride height when you search the archives it's incredible.

In the end I opted to go 'high' as no doubt the springs will settle. I'll then re-adjust to something a little lower perhaps assuming that I'm not clouting the speed humps, etc in my local area.

In terms of the actual measurement it is taken from the outrigger corners. I'm putting a straight edge across the corner and then putting a rule perpendicular from the straight edge down to the ground.

I'll have another shot at it tonight and see where I get to.

Ta

Ian

[jesfirth]

Just get it working and then take it to a Motorsport garage that can set it up and corner weight it for you. Anything else is pretty much pointless you will never get it remotely right yourself. Once properly set up and weighted you will be amazed at the difference in the handling. If you are in the south/ midlands Topcats are good. I have just had my griff done at Northampton Motorsport and it has transformed the car.

[billybradshaw]

jesfirth said:

Just get it working and then take it to a Motorsport garage that can set it up and corner weight it for you. Anything else is pretty much pointless you will never get it remotely right yourself. Once properly set up and weighted you will be amazed at the difference in the handling. If you are in the south/ midlands Topcats are good. I have just had my griff done at Northampton Motorsport and it has transformed the car.

I haven't managed to get any time in the garage tonight but I have been in touch with a colleague at work who also prepares race cars. He's offered me the use of his workshop which is great. So as you suggested, I'll get it there or there abouts and then trundle over and plonk it on the scales.

cheers

Ian

[billybradshaw]

So it would seem that my approach to setting the ride height was fundamentally flawed. The wooden blocks were a no no. Of course I knew this all along and I was just checking whether you lot noticed.................

What a chump!!! The blocks obviously have the effect of limiting the degrees of freedom that the chassis could move in so any amount of messing with the spring platforms at the rear would be completely futile with the exception of winding me up (if you'll excuse the pun).

So, another lesson learnt.

Cheers and thanks for the advice

Ian

[tofts]

Also, bear in mind that if you change the ride height, you will also need to do a geometry check as it will almost certainly change your camber and caster angle very slightly. So you could reset the ride height but still have a terrible ride.

If your friend has the facility as well, its going to be no Biggy!

J