Pruettfan

One other thought, as you heat up a tire to the extent that causes this kind of damage you know if pretty early on, the car develops an understeer. That is the time to slow down and give them time to cool off but your session is not wasted as long as you learn from the experience. If you push through and just continue to go for it the tires will do exactly what you have experienced. Negative camber will help but not totally eliminate this problem, more track oriented tires will help because they offer much more grip at the limit and are more heat tolerant but you can destroy any set of tires if you don't find the right setup and balance. Not that any of us here are pros but what separates the great drivers from the rest is often the ability to keep the tires at their best for the full stint. Watch a guy like Scott Dixon in Indycar put in lap after lap within 1/10th of a second while drivers around him go like hell at the beginning of the stint and fall off by 5-8/10ths within 10 laps.

Tief Lernen

Thanks for all the feedback! In retrospect I can definitely imagine how my line through a few corners would be tough on the FR tire - I was aware that I was turning in late and a bit abruptly. My understanding of "overdriving" is that you're saying I was turning the wheel past the point of understeer and just slipping the tires excessively without getting any improvement in turn rate? Yeah, I guess I was. I'll keep both of these in mind for next time.

I suspect it was a combination of all the factors discussed above - poor technique, not ideal tires, and not being able to get the tires up to temperature because of various incidents, slow cars ahead, etc. Plus the factory alignment.

Got this picture from the photographer at the last event. Those sidewalls don't look happy!

Hella-Buggin'

Chunks can mean heat cycled out. You need different tires for the track. Those don't have a hard enough sidewall to handle the side loads with the low pressures required to make it through a session.

Inrev

Gear Rower

I find as an instructor, once a driver gets comfortable at speed and has the basics of high performance driving down (knowing the line, smooth inputs, basic car balance concepts, etc), the next big obstacle to overcome is recognizing when their car is understeering and then how to correct it. Essentially, once the car has begun to push, you can only do two things: Back off the throttle and/or UNWIND the steering. It's initially counter-intuitive to do this, but adding more steering input (which is a natural reaction) to tires that are beyond their slip angle makes a bad situation worse.

A driver "overdriving" the car will initiate understeer by a combination of under-rotating the car and trying to carry too much speed. The steering input is then increased to compensate, the tires begin to slide and overheat, and the performance goes out the window. I've even watched drivers in this situation hammer the throttle to break the rear end loose/rotate causing compensatory throttle oversteer to counteract their entry/mid corner understeer. This is an exciting way to go around the corner, no doubt, but is certainly not the fastest and is a wonderful way to chew through the tires.

Key points to focus on are ROTATING the car at entry and then finding the optimal SLIP of the tires. You'll go faster (a LOT faster) and you'll save your tires, too. Sit in the right seat with a pro and you'll be amazed (!!) at how good they are at these two techniques.

Putting stickier tires on will only mask/compensate for sub-optimal technique. Street tires are fantastic for learning to rotate the car and find that magic slip angle -- You have to tune your butt, fingers and ears to detect the rotation, feel and hear when the tires start to push (street tires will chirp nicely as they start to go beyond their angle). Unfortunately, many drivers get pulled down the vortex of bigger, stickier tires, bigger wing, coil overs, more aero, more power etc before getting these essential techniques down. Did you ever wonder how the hell that 944/cayman/boxster is smoking all those carreras & GT cars in the advanced group??

jdistefa

^ /thread

A/S

The MP4S needs abnormally high pressures, and needs plenty of camber too. -2.5 front camber and -2.2 rear is what I found ideal with a pyrometer. Target pressures, I run 42psi front and 50psi rear on a car with stiffer springs than a 991 GT3 RS and stiffer aftermarket bushings.

Get a set of 19" wheels, go for Hankook RS4, Bridgestone RE71R or more expensive tires (Michelin Cup2, Trofeo R), and you can drive on the tires to the track day, just don't use these tires as permanent street tires, they will heat cycle out.

A 718 cannot get enough front camber for the MP4S, you'll max out around -1.2 degrees, so invest on camber plates to save money.

daylorb

I did not move to stickier tires from PS2/PS4 for a couple years as I was told the same thing. From what I have felt driving, I like to think of driving in snow. If you turn into a turn smoothly in snow, your car tracks and glides. Steer too much and your car goes straight with the tires trying to grab. Eventually it turns, but late and sharp. Braking in a straight line works, but break and turn and it gets a little dicey.

I try and emulate the instructors I have had who seem to gradually turn the car progressively more into a turn rather than abrupt, that seems to be a lot faster and easier on the wheels. Jamming them later/with brakes possibly still on not so much.

Frank 993 C4S

Steering speed changes from corner to corner. Low speed corners will require quicker steering inputs, faster corners not so much (but there are exceptions like the Inner Loop at WGI).. Use the brakes for balancing the car, especially brake release and how far you carry brake into a corner.