Oversteer/understeer Tyre pressure query
Discussion
Good Day Guy's.
I have some articles from 1987 by BF GOODRICH tyres referring to how to balance oversteer and understeer mainly for track work. [Plus suspension and handling etc articles from a 'Fast Car mag circa 1986!!]
This I have followed since.
However I noticed recently that various bits of editorial comments and information lately in the magazines states the opposite including the bit on Autocars Arial Atom at the Pageant of power last week.
Briefly :- My article states, generalising.
To reduce Understeer raise pressures at the front and decrease at the rear.
To reduce Oversteer raise pressures at the rear and reduce at the front.
The articles in the mag are suggesting that now the opposite is true.
[That is lowering the pressure increases the tyre footprint and therefore grip. Increasing them 'decreases' the tyre footprint and decreases the grip]
I would be very pleased for some helpful comments. Thank you.
I have contacted Tyre companies before re this and they have done the Health and safety line with use only the rec pressures as stated by the manufacturer etc. That is fine but does not help my understanding.
Cheers
Safe Driving! ANDY
I have some articles from 1987 by BF GOODRICH tyres referring to how to balance oversteer and understeer mainly for track work. [Plus suspension and handling etc articles from a 'Fast Car mag circa 1986!!]
This I have followed since.
However I noticed recently that various bits of editorial comments and information lately in the magazines states the opposite including the bit on Autocars Arial Atom at the Pageant of power last week.
Briefly :- My article states, generalising.
To reduce Understeer raise pressures at the front and decrease at the rear.
To reduce Oversteer raise pressures at the rear and reduce at the front.
The articles in the mag are suggesting that now the opposite is true.
[That is lowering the pressure increases the tyre footprint and therefore grip. Increasing them 'decreases' the tyre footprint and decreases the grip]
I would be very pleased for some helpful comments. Thank you.
I have contacted Tyre companies before re this and they have done the Health and safety line with use only the rec pressures as stated by the manufacturer etc. That is fine but does not help my understanding.
Cheers
Safe Driving! ANDY
Thank you guys for the interesting and informative feedback.
Sam I understand quite a lot which is how I came to read and save the previous. It would not have been dull and boring so thank you.
Time for some more reading I think.
I also got some general interesting replies on the general gassing forum too.
Cheers Andy
Sam I understand quite a lot which is how I came to read and save the previous. It would not have been dull and boring so thank you.
Time for some more reading I think.
I also got some general interesting replies on the general gassing forum too.
Cheers Andy
Thank you Sam.
Brilliant job.
Seems I had the right ideas in the head but your explanations have polarised/correlated them and it is easy to see a way forward.
I run a Renault sport megane RS 250 which has a lack of understeer compared with my previous VXR astra.
Howvere in oder to improve the Astra altered the pressures to get the balance I needed but went to far.
Oddly [and I could never get a reply from VXL] was that VXL altered the rec pressures for the rear mid life/model from 30 to 35 psi [orig 35/30 now 35/35]
So what did the find/discover?
The car was optimised on Millbrook and by Lotus on their track and the movement of the car was almost centred around the gear lever supposedly. So did they get too much oversteer as a side effect and what did increasing the pressure do in the end.
I will never know.
Sorry for the cross posts. It was a case of which forum to post General/track/Suspension.
Thanks again for your replies. [I wont buy the book now ha ha!!]
Cheers Andy
Brilliant job.
Seems I had the right ideas in the head but your explanations have polarised/correlated them and it is easy to see a way forward.
I run a Renault sport megane RS 250 which has a lack of understeer compared with my previous VXR astra.
Howvere in oder to improve the Astra altered the pressures to get the balance I needed but went to far.
Oddly [and I could never get a reply from VXL] was that VXL altered the rec pressures for the rear mid life/model from 30 to 35 psi [orig 35/30 now 35/35]
So what did the find/discover?
The car was optimised on Millbrook and by Lotus on their track and the movement of the car was almost centred around the gear lever supposedly. So did they get too much oversteer as a side effect and what did increasing the pressure do in the end.
I will never know.
Sorry for the cross posts. It was a case of which forum to post General/track/Suspension.
Thanks again for your replies. [I wont buy the book now ha ha!!]
Cheers Andy
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