Understeer - Prevention - ?
Discussion
There's limited scope with the spring rates since the chassis backbone has so little stiffness to transmit the consequent loads. Have you got a good dose of negative camber at the front? Something like 2° at least will help.
Also, if you are still running the standard 205/60-15 tyres, something a little stiffer, e.g. 215/45-17, will make the turn in more precise.
In the end, what really helps is more power to get the rear sliding. Better off with a V8 for that!
Also, if you are still running the standard 205/60-15 tyres, something a little stiffer, e.g. 215/45-17, will make the turn in more precise.
In the end, what really helps is more power to get the rear sliding. Better off with a V8 for that!
If you want to slightly adjust Over/Under steer without making any permanent mechanical changes you may be able to achieve what you want to achieve by very slight adjustments to tyre pressures. However, you need to be very careful that you don't overdo it. Vehicle manufacturers produce tables of tyre pressures for each vehicle to suit varying degrees of loading, i.e.(Driver only/Max Load etc.)not only due to the different loads being carried by the tyre but also because changes in loading also results in a change of balance in handling due to changes in tyre slip angles, due to increased or decreased tyre sidewall deflection.
Higher pressures will reduce slip angles due to lower sidewall deflection.
When the rear tyres have greater slip angles than the fronts, more oversteer is created. Therefore, to reduce Understeer raise pressures at the front and decrease them at the rear, to reduce Oversteer raise pressures at the rear and reduce at the front.
I cant stress enough to be very careful...... but slightly increasing the fronts from the manufacturers recommendations and slightly reducing the rears will increase oversteer. A couple of pounds either way front and rear will not cause major problems. I would guess some drivers rarely check tyres regularly enough anyway and pressures are way out so some subtle planned changes should be fine.
Let us know how it goes if you decide to try it !
Regards
Graham
Higher pressures will reduce slip angles due to lower sidewall deflection.
When the rear tyres have greater slip angles than the fronts, more oversteer is created. Therefore, to reduce Understeer raise pressures at the front and decrease them at the rear, to reduce Oversteer raise pressures at the rear and reduce at the front.
I cant stress enough to be very careful...... but slightly increasing the fronts from the manufacturers recommendations and slightly reducing the rears will increase oversteer. A couple of pounds either way front and rear will not cause major problems. I would guess some drivers rarely check tyres regularly enough anyway and pressures are way out so some subtle planned changes should be fine.
Let us know how it goes if you decide to try it !
Regards
Graham
The other thing is, if you have excessive toe-in, especially at the rear, you will get more understeer. That might be the case if the trailing arms have been replaced at some point and the toe not re-set correctly.
On the other hand, toe-out at the rear is usually a very bad idea, becomes very twitchy.
Further to tyre pressures, if you are doing a lot of track days, the left front usually takes a lot of wear and heat cycles, such that the tyre compound loses grip a long time before it actually wears out completely.
On the other hand, toe-out at the rear is usually a very bad idea, becomes very twitchy.
Further to tyre pressures, if you are doing a lot of track days, the left front usually takes a lot of wear and heat cycles, such that the tyre compound loses grip a long time before it actually wears out completely.
phillpot said:
Bit of useful advise I found while browsing t'internet.....
"Understeer" is when you hit the fence with the front of the car.
"Oversteer" is when you hit the fence with the rear of the car.
"Horsepower" is how fast you hit the fence.
"Torque" is how far you take the fence with you.
reminds me of the Walter Rohrl quote:"Understeer" is when you hit the fence with the front of the car.
"Oversteer" is when you hit the fence with the rear of the car.
"Horsepower" is how fast you hit the fence.
"Torque" is how far you take the fence with you.
When you can see the tree you're about to hit, it's called understeer. When you can only hear and feel it, it's oversteer.
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