Toe-out good or bad?

[ashaughnessy]

Car - 1987 live axle super sprint. A032R tyres, front suspension converted to add second upper wishbone link. 8% quick rack just installed. I used to have the wheels straight ahead, but they've just been adjusted to (I think) fifteen minutes of toe-out. The car now feels slightly less stable when travelling straight but possibly also has better turn-in. I'm not sure how much of either of these is due to the change of tracking setting or the new rack. What are people's thoughts on this - toe-out or straight ahead? If it comes to a choice, I'll live with less straight line stability if it gives me a better turn in, as I often have trouble on the track with understeer.

Also, could a change from straight ahead to toe-out cause a high speed vibration felt through the steering wheel? This vibration has just appeared, so I'm looking for causes and I thought the toe-out might be one. The wheels have been balanced recently, though I'm going to make sure the weights haven't fallen off when I get home tonight. The vibration wasn't there before the new rack was fitted and the tracking changed, but it might just be that the old worn-out rack was masking it.

Anthony

[Peter Carmichael]

I'd run whatever feels right. Toe is easy to alter, so mark up the track rods and try a bit less and a bit more.

 

The stability vs. turn in thing is key. I dislike unstable cars intensely; my Honda Integra was suffering from this until I worked out that the only adjustable suspension setting (toe) must have been wrong - I toed it in a bit (relatively: I still don't know what the setting is) and now everything is happy.

 

For road use I'd err on the side of stablity. There are many other tuning areas in the chassis, so if profound understeer is a problem I would sort that out elsewhere in the chassis and then trim the toe so that it is just stable.

 

On the Seven I sometimes change the toe setting for a track day.

[ashaughnessy]

Do you know what the track change is (in minutes/degrees) for a single turn of the steering arm within the track rod? I could try moving things about and seeing the effect, but it would be nice to know how big an effect I'm having when I make a change.

Anthony