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MG MGF Technical - Oversteer on turn in

I had my car at Knockhill for a track night which was fun, but I found that the car tended to oversteer as you turned into the corner. You could feed the power in from the apex to the exit and it felt fine, with no understeer.

The car has lowering knuckles, compliance washers, trophy shockers, Toyo Proxes all round, F 28psi, R 30psi, Alignment front is 10min IN each wheel and the rear is 5min IN each wheel.

Will adding more toe IN at the rear reduce the oversteer, if so, what sort of value should I try?

Thanks

Alastair
Alastair McLeod

I'd go the opposite way.

Parallel all round to start with gives a very neutral handling car on the track. Dial in oversteer by toeing in the front a little. Possibly add a little toe in at the rear, but not much.

Just my tuppence worth!! :o)

P.

Paul Nothard

I think your present settings are pretty good actually Alister :o) I'd not go for quite as much toe on the front out of personal preference (parallel or 5min toe in suits me). Regarding rear toe: increasing rear toe should make the back end less eager to turn in - so yes, that should reduce the amount of percieved oversteer.

Having said that, oversteer really should not have been a problem for you with the settings you've used. What wheel/tyre sizes have you got?

How are you entering the corner? Trailing throttle/ trail braking/ neutral throttle? The trouble I have with the steering of the F is the lack of communication through the helm: it makes it very hard to determine what the slip angles are up to, and as a consequence, it is very easy to apply too much lock...
I've also read that Toyos can perform very inconsistently on the track - IIRC overheating is a problem. Might be more on this on the Lotus BBS's
Rob Bell

Hi Paul

I'm sure Dieter tried parallel at the back and found it gave too much oversteer on the track, so I was going to increase the amount to toe in, as I'm only running 5min. I think standard is 10min +/- 6min.

As it is expensive to experiment, I would like to know what other people have used succesfully, as a starting point.

Cheers

Alastair
Alastair McLeod

Hi Rob,

I was braking in a straight line, comming off the brakes, then turning in, a small touch of opposite lock to correct the side, then back on the power. Once on the power the back end felt fine, it is just the initial turn in that was a problem, giving me no confidence to push hard.

I was using standard 15" wheels with 205's on the back and 185's on the front. Overheating may be happening as some of the tread appeared to have rolled over on the edges.

The steering was fine, no PAS, so I was able to feel what was going on and catch the slide.

Cheers

Alastair
Alastair McLeod

Alastair, I'm sure that parallel at the rear does not give huge amounts of oversteer. I'd also take heed of Rob's comments. He's done the reading on the suspension theory too. :o)

Rob, surely front toe in/out has more effect on oversteer? I know that after having parallel all round and changing to toe-in of ~7min at the front... it was oversteer city! Not nice.

P.
Paul Nothard

Paul, I have had toe out on the fronts a couple of years ago and this gave tyre wear problems, so I want to keep some toe in on the fronts. I could reduce it slightly, but I don't think it would be enough to cure the problem.

Alastair
Alastair McLeod

Hi Alastair,

Tried a few settings - I found that the rear end was somewhat unsettled with parallel rear. I think that suits some driving style better than others: I just found that entry/exit speeds were compromised when I tried this :o(

Bit more about toe-angles @ http://www.mgf.ultimatemg.com/tracking.htm

Paul, yes you're right that front and rear geometry have an impact upon oversteer characteristics. More toe-in front, in my experience too, makes the front of the car more 'pointy' - turn the steering into the corner, the change in direction could be quite agressive. When I tried parallel rear, it was with 5min toe in set at the front - perhaps this is the reason why I didn't get on with it all that well... with 5min toe in all round the car was much more benign.
Rob Bell

This thread was discussed on 14/09/2003

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