Andy S.

Having said that all single seaters run tall sidewalls. But these have different dynamics to road cars any way and alot of the suspension is in the tyres on these cars.
On the subject of Vehicle Dynamics had a training course with a ex Ferrari F1 suspension Technical director just before christmas. My head hurt after that beleive me! Anti dive, Anti squat, anti lift all done on 3D planes. But the car should benifit from it though.

Andy S.

What do you mean Mansell went quite well

LOL

johnfelstead

Andy, i live fairly close to you, would you be up for a workshop visit? I would quite like a close look at your cars.

Andy S.

Yes no problem John, You will have to excuse the mess though We have just moved in to new premise's and having 2 cars in build at the minute and still constructing the building. But you are more than welcome. If you mail me as per my profile then I will give you my mobile number.

SDB

John

are we still talking about the sprung / unsprung weight vs spring / wheel rate thing here? or have we moved on?

--

re: gyroscopic effects. Could you explain how that will improve the handling? The massive mechanical advantage of a car's steering makes this pretty much null and void. Are you getting confused with motorbikes?

There is the possibility that it has a very minor effect of very high frequency and heavy bump if lots of dynamic camber is at work, but I am not sure how it could be anywhere near enough to warrant a wheel choice that would effect the decision based on profile and weight.

Cheers

Simon

Andy S.

PS have you seen our web site www.djracecars.com

SDB

LOL re mansell

Andy S.

I know one of the designers at Prodrive, He told me they used to set up the suspension pickups and wheel positions etc to +/- 0.25mm but the drivers always seemed to go just as quick when they had hit some thing knocking the suspension out of line, so now they work to a 5mm limit!!!!!!!!!

johnfelstead

Too tired for this at the moment, i'll be back though, early start blah blah.

Dont underestimate the gyro effects of wheels, especially at high speed or where you are going airborn.

I'll drop you a mail Andy. Off to Oulton at 7am.

SDB

LOL

That sounds about right. On gravel, the tolerances really aren't as critical.. And in fact, in rallying on tarmac, they are not as critical as on smooth circuit racing.

An oposed but related story is one of Colin McRae who always insisted on ABSOLUTE dead centre steering wheel. To the point where he always had a retaining pin through the steering wheel when in service to ensure that all set-up kept the steering wheel bang on. During testing, they decided to test him out, and set it a fraction off centre, and the little git knew the second he drove off.

Cheers

Simon

johnfelstead

Most drivers will notice that, it's because of the angle your arms sit, its very easy to feel minute changes in those angles. That is my pet hate, off centre steering wheels, really anoys me.

SDB

John

Agreed re airborn. But even then the amount of control you have over the car whilst airborn due to gyroscopic effects is very small (it's there, but very very small) which could not possibly outweigh the benefits of a lighter wheel for the few occasions when you're on the ground

Cheers

Simon

Andy S.

Knew you where going to Oulton John, CW42 is going watching you!
Got the Kiddies tomorrow so might go watching my self for a hour.

SDB

John, they moved the steering by around 2 minutes. Most drivers do not feel that. Many do, but not most. That kind of difference can happen over the bedding in period of tyres, if a heavy passenger gets in, or you have a fraction of a psi difference in a rear tyre. If it was the difference in your arms, you could get that by having a slight ruffle in one of your gloves, or by sitting on your wallet.

Steering being out by half a degree to a degree is bloody annoying, but this is a different situation.

Cheers

Simon

johnfelstead

i felt the change when you were in my car Simon. I do drive with my fingertips though.

Come say hello Andy, i expect most of the day will be spent setting up a tarmac rally Impreza but if time allows i'll go for a spin in my own.

johnfelstead

and i think you are misunderstanding me, i would always want the lightest wheel/tyre combo, all things being equal.

SDB

I see you're not too tired to hang around for a quick insult John.

Can we keep this useful thread out of the gutter please? If you haven't got anything useful to add, please don't spoil it for others.

Regards

Simon

SDB

OK I see.

So what "not that simple" then?

Cheers

Simon

johnfelstead

Simon, you have seriously lost your sense of humour. Banter old chap, read back in the thread and you take the **** yourself about your weight. hence my smileys.

Chill out.

SDB

Sorry, I wasn't being touchy at all.. as can be seen by the very post you quote. I have absolutely no issues there at all.

I was just trying to be clear that this is a good topic, which you have made a number of comments on, the majority of which (I'll try to say this as humbly as possible) I've contradicted. You ignored one subject, and didn't comment on it any further, moving on to another. Then I contradicted that one, and you told us you were too tired, but you'll be back. Then you commented on another subject, which I contradicted, and you simply came back with a muppety dig.

Just wished you had spent the time adding to the thread / discussion.

Cheers

Simon

johnfelstead

Not touchy, you said i insulted you and was draging this into the gutter. make your mind up.

i was kept up doing something else i hadnt anticipated, hence the extra posts. Forget it simon, it's too much like hard work trying to have any discusion with you without you taking offence.

Goodnight.

SDB

LOL goodnight John.