London Show

[jeffko]

I did not see your post before my last one and I am very surprised to see your comments. I know my own experience with these tires on the street has not been good, but admittedly they were not hot. I never trusted them long enough to get them hot. Seems like I recall back in the 70s that they tires were certified to race or something to that effect. However, several track guys have told me that rubber tech has passed them by and they could not be trusted. I know myself I have laid some pretty hard launches, went back to do another and was surprised to not see the last launch. Now that's hard rubber. Thanks for posting your experience, but I am waiting just the same. Or maybe it's just the caution that comes with age.

The other factor is driving 400 miles, beating your car on the track for a couple days, hoping it survives for the London show and autocross and then driving 400 miles (hopefully) home. I do hope you guys are able to offer it next year.

This is my first trip to London so I am looking forward to it and meeting all you fine people that have worked so hard to put this event on for us all!

[rdorman]

Mid-Ohio has good run off room in the areas where it is really needed. As for tires, you know what higher performance tires do? They reduce the range of slip angle at the limit. What does that mean? Higher cornering speeds and less forgiving. If you have ever driven a race car on a track on racing slicks, you know what I mean. There is a VERY fine edge to balance upon. A street tire will create its max grip over a much, much broader range of slip angles and give you a LOT more notice before you go spinning of the track.

Racing tires increase corner speed, reduce the amount of warning before they loose grip and increase your chances of an off track tour if you don't know how to handle them! They are for experienced drivers.

If it where me, I would prefer to be running on plain old street tires for my first couple of times out. And as always, use your head and don't drive above what you can handle!

This is a school, so check with your insurance agent, mine WILL COVER ME and the car during a school. I have it in writing!

[jeffko]

Slip angle mainly focuses on the front "directional" tires. On an aggressive turn under power the car basically turns in yaw meaning the back tires try to follow the front without the benefit of being able to change their direction. While there is also slip angle on the edge of the rear tire's contact patch the lateral load builds much quicker than the front, again the tires are fixed direction, the slip area grows until the contact patch of the tire is to small and it lets go. I am just saying that with t/a tires this happens much more quickly because of the hard rubber composite. And yes they will make noise warning you of impending danger but they will make lots more noise before they finally break loose. So also quite deceiving.

When the contact patch is broken by irregularities in the road on a hard turn there is no warning. The sound you hear is not a warning, but the tires screaming it's too late! Much more prone to happen on hard rubber tires.

You may wonder where I get all of this since I don't have track time. Well, I have been reading books that explain what I was experiencing when I was younger. Still a novice though!

[rdorman]

All I can say is that I have driven my Cobra on T/A's, Yoko Avid S/T and slicks. The street tires gave far more warning then the slicks and where much more tolerent of me!

If you like reading on the subject. I highly recommend Milliken's Race Car Vehicle Dynamics. Best book I have ever read on the subject. It is a real page turner!

[jeffko]

I noticed that book, but frankly it was a bit intimidating for me. Maybe later when I learn a lot more. Sounds like you will be at Mid Ohio so have fun and be safe. See ya at the fling.

[rdorman]

It is a great one! And it is written so a non engineer can understand it. I greatly enjoyed reading it and go back to it from time to time. Look me up and I will try and remember to have my copy so you can check it out. It will run you north of $100 so you may want to look first.

[rob frink]

I was on Mid-Ohio last month. It has a new surface with revised runoffs and new curbing. I even think they made it wider. The new asphalt is smooth as silk!!!! No more concrete patches. What a pleasure!!

I can't wait!!

[dlampe]

I would also be cautious if I had to drive my car home. Track days are hard on the cars.

[OhBuoy]

Jeff & Company,

I am out for the Mid Ohio event as well. I really hope that they do it next year and I have an opportunity to participate. Much more important events have surfaced that I need to take care of, and I will not have time to get the car ready. Besides, I would probably end up crashing at the rate I am going.

Tom