Effects Of Too Much Toe-in

[Guest Dunebug]

Hello chaps,

 

I've just spent an enjoyable sunny afternoon trying to sort out my Exmo's front suspension geometry with mixed results. I did the tie-bar mod. a couple of years ago so I do now have control over the front castor.

 

Anyway, what a bl**dy nightmare!!! A Lotus 7 replica doesn't have many straight edges to use as a reference and those edges that are straight are not where they're supposed to be :gdit: I have however managed to set the castor to be approximately the same on both sides using some angle iron, a spirit level and a micrometer and I'm now reasonably happy with it.

 

Next came the tracking which I thought would be relatively straightforward. I decided with both castor and tracking to not bother about absolute values but just concentrate on getting both sides symmetrical and use trial and error to get the right settings for my own, unique, car.

 

Anyway, I got the tracking approximately the same on both sides (I'll post my method if anyone's interested) but I think I might have too much toe-in. The steering has very little feel and virtually no self-centering ability although the car brakes and accelerates in a straight line but the tyres become quite warm after a run. There is plenty of the 'correct' castor i.e. hub leads the suspension top mount so I don't think that castor's a problem. Do these symptoms sound like too much toe-in or do I need to re-think my castor guestimate?

 

Thanks,

 

John.

[Guest Takumi]

I think that too much toe in can cause the steering to be too heavy, trying to snap back to centre with much more force, ive noticed that some racing cars have lots of toe-in, not sure if this improves corner handling...

 

 

tak

[Guest madmax]

If you are not sure the tracking is correct why not have it checked at your local tyre depot? Also castor and camber angles should be accuratly set as no self centering usually means to little castor. Good luck Colin

[Guest jon paul]

Tyre pressures are the first thing to make sure are correct / uniform

 

I back up Colins' theory, get to a wheel alignment centre and get a printout of the figures.

 

Preparing to be shot down :gdit: .

 

I think I'd be looking towards +3 to +5 degrees of Castor,

-30' to -1 degree of Camber,

+2' to +5' of Toe per wheel (+4' to +10' Total)

 

Get them to check the 'Toe out on turns' figure as this can 'deaden' feel also.

 

If possible have the car corner weighed and check the weight bias

 

Heat is not neccessarily an issue as long as the temp is evenly spread, look for a spread of not more than 25 degrees C (Inside to Outside). Slightly larger if running more negative camber