Damper rate

[Frosty]

Frosty - we are talking ride heights here and nothing to do with weights. The front end of the chassis is the same dimension from the ground on both sides so the rear should also be the same height from the ground on both sides but its not

No. Why should it be the same?

[John Loudon - Sponsorship Liaison]

Because I would expect Westfield to have welded the chassis true and square!

[Terry Everall]

All this discussion and it probably has minimal effect on the cars performance for most drivers!!!!!!!!!!!!!!

I do not corner weight my car but I do set them up with front ride heights the same and rears as near as I can get it with me in drivers seat. ( Its hard to get it spot on due to assymetrical loads involved at the rear)

[nikpro]

It was Stephenh's post that has now been deleted that I was stating was incorrect. Basically he was saying the rear offside should be higher when unloaded so that when the driver gets in it assumes the correct ride height.

As I have explained this is not true when corner weighting.

There can be only minor differences in ride heights at the front yet major differences at the rear. The CoG is probably where the drivers b*****ks are when there is only the driver in it.

As per Terry - I don't corner weight mine (have all scales etc) because I think it is a waste of time for my trackday use.

[Arm]

QUOTE

As per Terry - I don't corner weight mine (have all scales etc) because I think it is a waste of time for my trackday use.

That explains your lap time then.

(now I didn't say if they were good or bad)

[Scottish Bloke]

I've just read this whole post, fair to say there are some valid points and looking at the photo in the original post it's clear to see all is not well with setup.

ARB's will help for sure, what spring rates do you have f&r, what does the car weigh etc etc etc

Yes the car needs sorting out by someone who knows what they are doing but get some driver tuition before you go throwing buckets of money at your car! Looks like 90% roadcar after all.

[adamnreeves]

I've just read this whole post, fair to say there are some valid points and looking at the photo in the original post it's clear to see all is not well with setup.

ARB's will help for sure, what spring rates do you have f&r, what does the car weigh etc etc etc

Yes the car needs sorting out by someone who knows what they are doing but get some driver tuition before you go throwing buckets of money at your car! Looks like 90% roadcar after all.

Total car weight with driver is 777.5kgs, this is distributed as LF 176.5Kg, RF 187Kgs, LR 190Kgs, RR 224Kgs. Cross 48.4%.

Standard westfield gaz dampers with springs. Checking my invoice from westfield. The rear springs are listed as 195lbs. invoice for front just says standard front springs. I am lead to believe this means 350lbs?

The dampers have max of 24 positions for the dampers. I have the rear set to 12 and front set to 13. Tyres are medium compound toyos R888s, rear is 225/50/15 fronts are 205/50/15. Cold tyre pressure set to 18psi. Fuel tank had over 30litres of fuel in at the time.

[Frosty]

Because I would expect Westfield to have welded the chassis true and square!

You can set the ride height of any corner you like, to almost anything you like (within reason).

The chassis can be 100% perfect, and I can still set different ride heights at all 4 wheels. In fact, I would probably need to in order to get corner weights to 50% cross weight.

What I'm saying is that if the ride heights differ from left to right, it means nothing in terms of the condition of the chassis.  

[Frosty]

Total car weight with driver is 777.5kgs, this is distributed as LF 176.5Kg, RF 187Kgs, LR 190Kgs, RR 224Kgs. Cross 48.4%.

Standard westfield gaz dampers with springs. Checking my invoice from westfield. The rear springs are listed as 195lbs. invoice for front just says standard front springs. I am lead to believe this means 350lbs?

The dampers have max of 24 positions for the dampers. I have the rear set to 12 and front set to 13. Tyres are medium compound toyos R888s, rear is 225/50/15 fronts are 205/50/15. Cold tyre pressure set to 18psi. Fuel tank had over 30litres of fuel in at the time.

It certainly sounds in the right ball park. Personally I'd go a little higher on the rear springs - maybe a 225 since there is a lot of weight at the rear of the car, and even more if you carry a passenger. 225-250 would be my choice based on those weights.

The fronts I'm not sure about since I don't know the motion ratio of the standard track. 350 sounds reasonable though.

I would say that ARBs front and rear have to be your next modification, and then go from there really.

[stephenh]

Because I would expect Westfield to have welded the chassis true and square!

You can set the ride height of any corner you like, to almost anything you like (within reason).

The chassis can be 100% perfect, and I can still set different ride heights at all 4 wheels. In fact, I would probably need to in order to get corner weights to 50% cross weight.

What I'm saying is that if the ride heights differ from left to right, it means nothing in terms of the condition of the chassis.  

Frosty of course you can, but surely you can see that if you alter the height of the chassis at one corner it will alter the height on at least one other corner? You cannot get away from that, unless your chassis is made from plasticine or some such maleable material! So ask yourself again, how can the ride heights at the back be different, but at the same time be equal at the front?

I'll bet you an Elite sequential box that you cant achieve that on my car, on a level floor, without flexing or twisting the chassis!! To be quite clear, lets be more specific: can you get my chassis to be 125mm above a flat surface on each front corner of the chassis, whilst at the same time having one rear corner of the chassis 165mm above same flat suface, and the other rear corner 145mm above the same flat surface? You mustn't twist the chassis by either flexing or bending it, it has to remain in a flat plane on the bottom, the way it was when it left Westfields. If you can do that you're £3,000 richer, if you take the challenge and cant then you owe me one new 5 speed Elite sequential dogbox!!

[Frosty]

Frosty of course you can, but surely you can see that if you alter the height of the chassis at one corner it will alter the height on at least one other corner? You cannot get away from that, unless your chassis is made from plasticine or some such maleable material! So ask yourself again, how can the ride heights at the back be different, but at the same time be equal at the front?

I'll bet you an Elite sequential box that you cant achieve that on my car, on a level floor, without flexing or twisting the chassis!! To be quite clear, lets be more specific: can you get my chassis to be 125mm above a flat surface on each front corner of the chassis, whilst at the same time having one rear corner of the chassis 165mm above same flat suface, and the other rear corner 145mm above the same flat surface? You mustn't twist the chassis by either flexing or bending it, it has to remain in a flat plane on the bottom, the way it was when it left Westfields. If you can do that you're £3,000 richer, if you take the challenge and cant then you owe me one new 5 speed Elite sequential dogbox!!

It does alter another corner slightly, but not much because of the springs.

Are you honestly claiming it's impossible to set 4 totally different ride heights at 4 different corners unless your chassis is bent? I would take your money, but I like to feel I've earnt it and this would just be like taking candy from a baby.

Let me ask you something - have you ever actually set up the ride height of a car YOURSELF before?

With every set of adjustable suspension I have ever fitted to any car, before setting ride heights, I measure the current ones so I know roughly how much to wind up or down. On each occasion the car has had a different ride height at each corner. It's then your job to even these out by winding the platforms up or down to get to a base setting and then drive it.

I use a 3 tonne jack though, so perhaps this bent my chassis?

[pistonbroke]

All this tecky talk about corner wieghting is great,  but looking at your first post picky No1.  

To my eyes it seems as if you have tried to carry to much speed into the corner , gone in too deep, missing the apex completely  

Could the cars attitude be down to the late (later) braking forces involved plus the coast side effects of differential loading the suspension and making the car corkscrew .

Hard to tell from a static picture but just my 2 cents worth but I would be wanting to check brake balance and possibly diff set up , is it LSD ?

[John Loudon - Sponsorship Liaison]

Are you honestly claiming it's impossible to set 4 totally different ride heights at 4 different corners

No we are not. The point is 2 of the ride heights are the same across the front axle which if is correct, the rear axle should have 2 ride heights the same as well (but not necessarily the same values as the front)

[Rory's Dad]

All this tecky talk about corner wieghting is great,  but looking at your first post picky No1.  

To my eyes it seems as if you have tried to carry to much speed into the corner , gone in too deep, missing the apex completely  

Could the cars attitude be down to the late (later) braking forces involved plus the coast side effects of differential loading the suspension and making the car corkscrew .

Hard to tell from a static picture but just my 2 cents worth but I would be wanting to check brake balance and possibly diff set up , is it LSD ?

I agree - it looks to me that the car has lurched into the corner carrying much too much speed       .  No tyre smoke or black lines and you may be starting to apply some opposite lock to prevent the spin

Mind you I know nothing...

Rory's Dad

[stephenh]

Like John says.  

Forget about the springs, Frosty, they are just supporting the 4 corners of the chassis when the car is stationary. Let me make it really simple. Lets assume the chassis is exactly rectangular, unlike a Westfield. Let us also assume that we start with all 4 corners at the same height. Now, lift the right rear corner by, lets say, 10mm. If we dont want the left rear corner and the right front corner to move, and we clamp tem in some way to prevent them from moving, what will happen to the left front corner? It will have to fall by 10mm. Otherwise it is a physical impossibility to raise the opposite corner. That has nothing to do with corner weighting, it is simple mechanics. You cannot lift one corner without either lowering the opposite corner or by raising at least one other corner if the chassis is not going to flex or bend.

Put it yet another way, you cannot raise or lower one corner and still leave the other corners unmoved.

Try it with your ruller, or any flat solid more or less rectangular item.

If I jack up one of my wishbones with my trolley jack, it will alter the height of at least one other corner of the car.

Now do you see? If not, you'd better ring Beagle Engineering and order my new gearbox!