Johnny G Pipe

When I replaced my shocks we took a slightly unscientific approach to geometry: Spring perches at same height as before, and as much front camber as possible. Can't do that in a 993..

The car is great, pointy and much less understeer unless very low traction conditions - when the wheels don't grip enough to roll into the camber.

At parking speeds, however, the front tyres seem to be pushing and scraping a little, and more than once I have felt that a steering input that was fine for my old setup sends me into a feeling of imminent body-roll oversteer as the front grips suddenly I guess I need less 'forearm shove' now..

Anyone any inputs? Am I going to wear my tyres weirdly?

Red rooster

Johhny ,
Got any alignment numbers ? I guess 3-4 degrees of negative ? Why cant you do that with a 993 . The front ends are the same .

Geoff

Johnny G Pipe

Hi Geoff.

No numbers - I don't have the tools -but not as much as that I don't think. IIRC cup cars came with negative 2.6.


My reference to 993's was their apparent sensitivity to alignment with the multi link rears. I also wanted to mention a 993 in my 993'rd post!

Hows the weather in Halifax?

CraigC

When I replaced the stock suspension on my car and lowered it to RS height it had -3.5 and -3 on the front wheels. Im pretty sure it would have worn the tires on the inside edge in a short time. My toe and caster were also out and even though the car cornered like a slot car the handleing felt a little off when going down a straight road. You really need to get an alignment. I had mine done at European RS spec by RUF in Dallas and I love it. The car handles much better than stock and will now track straight and true and Im not worried about ruining my expensive tires.

ThomasC2

More than -2,0 camber at the front is just a waste for street use.

Johnny G Pipe

Thanks for the inputs.
I'm trying to find out from searches how much maximum is. So far it looks like +/- 1.7 deg? Does the maximum just depend on the wheel carrier, or will different strut/spring combinations change this too?

My current tyres are on their last legs anyway, but I guess I can't get away without a professional 4 wheel alignment after replacing springs and shocks. Trouble is the car seems pretty good already, if a tiny bit twitchy on fast straightlines..

Red rooster

Johhny,
Weather here is great . To be honest I am amazed at what you are doing .
Without a real 4 wheel alignment you have to be wasting tires and time !
Maybe this is just fun to see how quick you can destroy the tires !!

Be careful to keep it on the road .

Geoff

Marc Shaw

I have -2.5 front and -3.0 rear but do as much track time as possible.

I find it a little squirelly at moderate speeds but it really turns in easily and seems to settle down once you get above 70 km/h - below that it is certainly darty.

I would think that there is no benefit to those types of numbers for a street only car as tire wear is certainly increased (esp. rear).

Marc

ThomasC2

more rear than front camber?! Is that a C4 thing?

Marc Shaw

No, just a personal thing.

I needed -3 to fit the 18" wheels in but found -3 on the front made the dartiness at speed more pronounced - reducing it to -2.5 reduced the dartiness without impacting on turn-in or cornering feel.

I don't know - perhaps it does relate to being a C4.

Marc