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Tyres
Ronin - 5/7/05 at 03:07 PM

After a phone call to Autotune have spent the day setting up the suspension. Feels about right, although ride is maybe a little on the soft side. Only thng is I get a lovelly squealing noise from the tyres. It doesn't matter what pressures I set them at they still seem to squeal even on gentle bends. I've tried everything from 14psi to 21psi. The factory recommend 14-16psi. Anyone any suggestions?

britishtrident - 5/7/05 at 03:39 PM

Sounds like you have an ackerman angle problem either too much or too little or even negative ackerman --- squealing will be from the inside front tyre getting scrubbed.

JoelP - 5/7/05 at 06:05 PM

it could be poor tyres showing up the ackerman discrepancy - i suspect that very few cars have perfect ackerman geometry. What make are the tyres?

britishtrident - 5/7/05 at 06:27 PM

I had a look at picture of the Gemini chasis difficult to get a decent look at the steering rack mountings but I suspect the steering rack is mounted to far forward -- this will give toe-in in turns scrubbing the inside tyre.

[Edited on 5/7/05 by britishtrident]

[Edited on 5/7/05 by britishtrident] Rescued attachment good.jpg
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britishtrident - 5/7/05 at 06:27 PM

bad Rescued attachment bad1.jpg
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britishtrident - 5/7/05 at 06:28 PM

Just plain silly Rescued attachment bad2.jpg
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Ronin - 6/7/05 at 07:19 PM

Spoke to a couple of other Gemini owners and Autotune and Ackerman angle has never been a problem with the Geminis. Could it be perhaps the wheels are slightly out of line with each other? I haven't had chance to check if it is only turning one way or both ways yet.

ps Tyres are 'Viking'. Never heard of them before. Think I will change to Yokos as they were recommended by Anthony at Autotune.

JoelP - 6/7/05 at 07:55 PM

check your tracking. Can be done by hand with a long piece of wood.

britishtrident - 6/7/05 at 08:26 PM

quote:
Originally posted by Ronin
Spoke to a couple of other Gemini owners and Autotune and Ackerman angle has never been a problem with the Geminis. Could it be perhaps the wheels are slightly out of line with each other? I haven't had chance to check if it is only turning one way or both ways yet.

ps Tyres are 'Viking'. Never heard of them before. Think I will change to Yokos as they were recommended by Anthony at Autotune.


The static toe setting would have to be massively out to cause tyre squeal so much so you would see it. As JoelP sugested you could do a very rough check with two long straight planks of would but you should have set this before took the vehicle on the road with new tyres. The direction the turn is made should make no difference -- if it does it could be you have set the corner weights so far out you are effectively driving 3 wheeler.

Viking are a second line tyre while not ideal for any vehicle with any pretence at performance on thier own they won't cause tyre squeal of the severity you describe -- the bigest disadavantage of them is probably lack of wet weather grip compared to big name tyres.

Ronin - 6/7/05 at 10:08 PM

Will check the tracking. Unfortunately I bought the car supposedly ready for SVA (so far new extension on steering column, partial rewire, strip and rebuild of carb, the list goes on) . As you can guess it wasn't. I will also give Autotune a ring again.

Tanks for the help.