Tires

Okay, this Board seems slow so here's a question. Besides being hard to turn the steering wheel wiht the car at rest, is there any down side to wide tires.

Someone's earlier post suggested the widest possible tires (rather than spacers). Here's why I have asked....I had hopes this 911 would teach me more about motoring. It has. for example: It seems that autocrossing is ALL ABOUT TRACTION. Period.

I'd like to reduce the cornering limitations I've discovered in my car. I suspect that wider tires (and/or race tires) is perhaps the most meaningful way to fix this (traction) problem.

Warren, it seems to me you disclosed your tire/wheel sizes. Can you do this again? BTW, I can see more and more how perfect a '73 S is with flares.


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'83 SC

Jim,

Have you been out crowding those orange traffic cones again?

My fronts are 225/50-15's on 8" wheels, and my rears are 285/40-15's on 9" wheels ... in an ideal situation ... that is, if I could find a pair of 11 x 15 Fuchs for less than the price of a used VW Beetle, I would put 345/35-15's on them and move my 285's to the front. Might require Popeye's biceps in an autocross, though!!!

One comment about traction ... heavier anti-roll bars, adjusted and balanced for 'neutral' cornering, so the car stays 'flat' to a greater degree at 1 g cornering levels than a typical 'street' car ... keeps the maximum area of your tire's contact patch on the ground, and hence, allows better control and 'Pointability and Tossability' ... very important assets in an autocross!

P.S. ... Anybody interested in visiting the chat room?


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Warren Hall
1973 911S Targa

We think alike on this subject Warren. I've got 255/45s on 9x15 front and 345/35s on 12x15s rear. I considered 285s for the front but didn't want to risk binding on the lock to lock turn. This combo eliminates any thought of lift throttle oversteer making a mediocre driver (me) safer. The only drawback I can think of is that great big tires allow absolutely no slipping. This can be hard on clutches and other drivetrain parts. There are times when you want a little slippage to keep the RPM's in the power band (it is also not possible to safely do a 4 wheel drift). One big plus is asthetics - these things really look good tucked under the flairs!

Warren and Rarly8, I'm guessing you both have turbo flares installed on your cars? Geez...how do you afford the rubber?

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Leland Pate

___79 SC Targa

I run Yoko AVS Intermediates. My first set were Pirrelli at TWICE the cost. They didn't last 15,000 miles. The Yokos now have ~8,000 miles on them and look like they may last longer. Here is something that most people don't think about - the actual measurements of identical tire sizes can vary with the manufacturer. My Yokos are 3/4 inch wider than the same size Pirrelli. This caused some spacer manipulation to prevent rubbing. Just something to keep in mind when you are "on the edge" with fitment. OH, and yes the car has 930 flairs.

It looks like there are still some real easy ways for me to spend substantial sums of money on my car. That's a relief!

My car is 'bone stock' and I'd like it to perform better. Yes, Warren, some orange cones woke up sore on Sunday.

My car has what appears, even at a glance, to be quite a bit of negative camber in the rear. This, I suspect, was to get at least one tire square to the road in hard cornering. Two would be better, which requires suspension parts.

Suspension parts would put me in the "P" class at autcross. As would race tires. I'm getting the feeling that tires alone will result in the largest cornering improvement of all possible modifications. This leads me to the thought that, even for street use, wider is simply better. I'm not Popeye, but I'd probably just have more fun wrestling with a livelier steering wheel.

It is all becoming clear to me. Technique and traction.

Here's how you tell the Stock class cars from the 'modified' cars: In the Stock classes, the tire squealing is WAY louder than the engines. With the modifieds, the tires are nearly silent and the engines are decidedly not.

I'm also suspecting that the 'turbo tie rod' upgrade is one of the first I should consider, given my love for just driving the car.

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'83 SC

Glad to hear you aren't giving those cones any mercy on Sundays!

Actually, I have known quite a few people that kept their cars stock, and were perfectly happy autocrossing ... just learning about the car's (and their own) limits, and having great fun doing just that!
Unless your tie-rod ends have measurable play, I don't think there is any need for the Turbo-ends because the 'stock' 911 parts really didn't have any problem ... if you can't feel any 'wiggle' when you grab the front tires at the '3 and 9' position and try alternate push-front, pull-rear, then, the reverse on the tires, you probably don't need new tie-rods!

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Warren Hall
1973 911S Targa