Damper rate

[SteveD]

you would not believe how much twist you can get in a westy chassis with very little force on a front corner ,if i can work my pissin phone il post a vid in a while

this is what i said , no mention of corner weighting or ride height twisting a chassis  

[Northampton Motorsport]

Adam I have been watching this thread with interest and just wanted to give my input to the debate. A lot of the advice you are getting is sound but I think you need to remember your original brief.

If I remember correctly your under slung exhaust was limiting setting the car to an optimum ride height and unless I am confusing you with another customer you said you already had to use planks to get in and out of your drive and onto the road and therefore the car could not go any lower.

Also we discussed spring rates and particularly damper settings and again you wanted to retain some level of comfort for a car that was going to be 90% road and occasional track fun.

From the picture I would agree that the attitude of the car is partly due to carrying too much speed into the corner and then backing off and adding lock. Anti roll bars would help with roll stiffness without destroying the ride completely.

We set up a lot of cars so I can’t honestly say I remember your car in detail I but I do remember the right rear being unusually heavy especially as you are a fairly light driver. Normally I favour setting the car up with a 50% cross weight which always results in the front weights being different by between 15 to 20 kg’s but because of the very heavy right rear and the fact that it was a road set up we decided to compromise on the cross weight.

On the geometry we did have the issue with limited adjustment due to the rose joint being necked out but again decided that running less camber would aid straight line traction under acceleration and braking. This seemed a perfectly sensible decision given 300 bhp and lots of torques plus 750kg’s

I don’t think the ride heights are an issue, it’s a Westfield, and as good as they are they aren’t that sophisticated a chassis. In 2006 I was involved in a shunt at snetterton that badly twisted upwards the front left corner of the chassis.

With no time to straighten it before the last 2 rounds of the season we ended up fitting a 1 ½ inch extension to the left front damper which allowed us to get the weights back to normal. With the geo reset the car finished 3 at Mallory less than a second behind the winner who was the champion elect and also 3rd at Oulton Park.

The car was not as well balanced as usual but was by no means an unmanageable handful.

Finally, Adam if you fancy another day out in sunny Northampton I will happily recheck it for you FOC

Regards Troy

[stephenh]

What a brilliant offer!!

[stephenh]

you would not believe how much twist you can get in a westy chassis with very little force on a front corner ,if i can work my pissin phone il post a vid in a while

this is what i said , no mention of corner weighting or ride height twisting a chassis  

Quite right, Steve. It was Nikpro who suggested it might account for some difference I think (post 91).

If the chassis doesn't deflect in corner weighting, then I would have thought, given that the front of the chassis is about half the width of the rear, that for a height difference of 13mm at the rear, the difference at the front is going to be about half that, ie about 6 or 7mm. But there again, maybe Adam didn't measure as accurately as he thought, or perhaps his floor isn't quite as level as he thought?

[adamnreeves]

you would not believe how much twist you can get in a westy chassis with very little force on a front corner ,if i can work my pissin phone il post a vid in a while

this is what i said , no mention of corner weighting or ride height twisting a chassis  

Quite right, Steve. It was Nikpro who suggested it might account for some difference I think (post 91).

If the chassis doesn't deflect in corner weighting, then I would have thought, given that the front of the chassis is about half the width of the rear, that for a height difference of 13mm at the rear, the difference at the front is going to be about half that, ie about 6 or 7mm. But there again, maybe Adam didn't measure as accurately as he thought, or perhaps his floor isn't quite as level as he thought?

Hello Stephen,

Cannot be bothered to check which post now, mainly because this is a long thread and my internet connection is too slow but I did post that my floor is only spirit level level and using a set square to measure it is accepted that this is only going to be rough. Also I posted later measurements, I think the difference at the front was about 5mm.

[nikpro]

I am not sure if everyone is winding Adam up or not but there seems very little wrong with his ride heights IMO.

If the car has been corner weighted then the drivers side rear should be lower when the driver is not in the car. (and whilst he is in the car).

The 'heavy' corner on a westfield is usually the offside rear as the driver almost sits directly over it; to 'reduce the percentage crossweight on the rear offside/front nearside diagonal the rear offside spring will have been 'unwound' on the damper - hence the car sits lower on this corner.

TBH the photo looks far more like poor corner execution on the drivers behalf than car set-up. (Running very wide on exit and applying more lock to steering)

Which was in response to your earlier (now deleted) post Stephen about the offside rear corner should be higher.

The point at which the rear ride height is measured I would guestimate at least three times wider than the point at which the front ride heights are measured at (the front lower chassis rails are a lot closer together than the front upper chassis rails).

So with the possible deviations i mentioned in post 91; I will say again - Nothing looks wrong with Adam's set-up.

[adamnreeves]

Adam I have been watching this thread with interest and just wanted to give my input to the debate. A lot of the advice you are getting is sound but I think you need to remember your original brief.

If I remember correctly your under slung exhaust was limiting setting the car to an optimum ride height and unless I am confusing you with another customer you said you already had to use planks to get in and out of your drive and onto the road and therefore the car could not go any lower.

Also we discussed spring rates and particularly damper settings and again you wanted to retain some level of comfort for a car that was going to be 90% road and occasional track fun.

From the picture I would agree that the attitude of the car is partly due to carrying too much speed into the corner and then backing off and adding lock. Anti roll bars would help with roll stiffness without destroying the ride completely.

We set up a lot of cars so I can’t honestly say I remember your car in detail I but I do remember the right rear being unusually heavy especially as you are a fairly light driver. Normally I favour setting the car up with a 50% cross weight which always results in the front weights being different by between 15 to 20 kg’s but because of the very heavy right rear and the fact that it was a road set up we decided to compromise on the cross weight.

On the geometry we did have the issue with limited adjustment due to the rose joint being necked out but again decided that running less camber would aid straight line traction under acceleration and braking. This seemed a perfectly sensible decision given 300 bhp and lots of torques plus 750kg’s

I don’t think the ride heights are an issue, it’s a Westfield, and as good as they are they aren’t that sophisticated a chassis. In 2006 I was involved in a shunt at snetterton that badly twisted upwards the front left corner of the chassis.

With no time to straighten it before the last 2 rounds of the season we ended up fitting a 1 ½ inch extension to the left front damper which allowed us to get the weights back to normal. With the geo reset the car finished 3 at Mallory less than a second behind the winner who was the champion elect and also 3rd at Oulton Park.

The car was not as well balanced as usual but was by no means an unmanageable handful.

Finally, Adam if you fancy another day out in sunny Northampton I will happily recheck it for you FOC

Regards Troy

Hello Troy,

Your memory is indeed correct. I have under slung exhausts and I have to use two planks of wood to get off my drive due to the gradient difference  between my drive and the pavement.

Indeed you are also correct that the car is mainly to be used on the road but this thread very quickly became track focussed of course   I found I had to keep reminded myself of this fact with the replies I was getting. I think on one occasion I said I do not want to comprimise it's road use. However I will add a friend of mine was following me on the road and I was driving slow enough for him to keep up with me bearing in mind he was in a 1.6 Astra. We travelled over 4 roundabouts together and when we arrived at our destination he told me that the Westfield showed lots of Roll.

I dismissed this as a flippant comment at the time but then a few weeks later I did a track day at Curborough and the resulting photo which is the worst of the lot due to my incorrect driving seems to back his original comment up. Since this photo I have added 2 clicks all round which you said I should do if it doesn't comprimise the comfort to much. I then thought if my Westfield does not handle as good as a small family hatchback then I have a problem. I decided to make a posting on here. Furthermore people where making comment that road going luxury cars have less roll adding more fuel to my concerns.

I got overwhelmed a bit but all the advice and comments. I know very little about this subject. Reason why I came to NMS to get all this set-up. I am sure with the intended use of the car, within the constraints and the car current configuration that NMS have undertaken to set-up the car as good as it can be. Driving to NMS get the suspension setup and then driving back I could feel a world of difference with the handling.

So taking all the advice I've been given. In summary I feel that all I need to do is install front and rear ARBs and leave the springs alone and possibly remove the 2 clicks off all dampers that I have applied to the base setting. If I understand this, this means I get to keep the car comfortable on the road but the roll will be much reduced.

Troy, really appreciate the FOC check and if I can be a little cheeky, maybe I ought to come along after I've installed the ARBs  however it definitely will not be sunny

[Northampton Motorsport]

No problem Adam just give me a shout when your ready

regards troy

[adamnreeves]

No problem Adam just give me a shout when your ready

regards troy

Wow, Thanks Troy. In the words of StevieD, I wuv you.  

[SteveD]

ahhhhhhhh a whole lot a wuv

[Cleggy the Spyder Man]

I am off to get mine checked over FOC