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 magazines 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 magazines 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
The later article is nearer to the truth, you'd soften the front to reduce understeer, soften the rear to reduce oversteer.
What you are actually doing is altering the grip ratio front to rear so alternatively you can stiffen the opposite end, has the same effect balance wise.
Altering tyre pressures is usually a last resort as the infaltion pressure should be more about contact patch than grip ratio but if you don't have adjustable dampers, arbs etc. it's pretty much the only way.
Maxx
There is no definitive answer to your question(s), there's just too many variables to take into account. The problem with magazine articles is they make too many sweeping statements.
Every car requires something different
Every derivative of every car requires something different
Every tyre requires something different
Every surface requires something different
Every circuit requires something different
Every temperature on the day requires something different
Every weather condition requires something different
Every driver requires something different
My advice is this....
Find some base "settings" that work for you and make a note of them. Adjust those base settings accordingly to suit the conditions on any given day and make further notes. Over time you will accrue a comprehensive set of notes that cover all eventualities.
Just make sure you enjoy yourself while you're doing it. They're track days, not life and death.
Every car requires something different
Every derivative of every car requires something different
Every tyre requires something different
Every surface requires something different
Every circuit requires something different
Every temperature on the day requires something different
Every weather condition requires something different
Every driver requires something different
My advice is this....
Find some base "settings" that work for you and make a note of them. Adjust those base settings accordingly to suit the conditions on any given day and make further notes. Over time you will accrue a comprehensive set of notes that cover all eventualities.
Just make sure you enjoy yourself while you're doing it. They're track days, not life and death.
Edited by Rill on Thursday 1st September 21:42
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