Temperature and Tyres

[Flatjack]

The situation is that I will be running a formula 750 car with its regulation tyres which have a blistering temperature of 120 deg. however the cars at max will only generate 70 deg at max.

In your opinion how close would you want to run to the blistering temperature and how you generate the extra heat? Remember it is in the region of 50 degrees to the blistering temperature.

As an example would you try using in car heaters, from a road car, which run from the hot engine water, to blow hot air into the wheel wells? Do you think this would make any difference?

Any answer is appreciated.

Dion

[boyracer]

You will probably need to call the company that makes the tyre you run and ask them what temperature is best. As you are circuit racing I would have thought the colder you can keep the tyres the better. Of course they need to run at temperature to produce the required level of grip, but ask yourself "how accurate are my measurements ?". I would assume you're not data logging tyre temperatures (I could be wrong) so the temperatures you're measuring are quite probably after a cool down lap and back into the pits then out of the car, find the thermometer and check the temperatures. Alot of heat can be lost in this time. It would be quite reasonable to expect that while the outside tyre is fully loaded (during a fast corner) that the tyre temps could rise to the blister temperature, but then during the short straight to the next corner it could cool down enough that when subjected to the same treatment on the next corner that it still only comes close and does not exceed the blister temp.
Oval track racers adjust tyre pressures to increase tyre temperature during the turn but it is a compromise, more heat at the start of the corner improves turn-in but sacrfices it later in the turn.
Most importantly as I understand is the temperature gradient across the tyre. If the inside of the tyre is 10º hotter than the outside, start worrying. If it's even — drive harder

[racealign]

i worked for a race tyre company for 10 years and have done tyre testing for all types of racing in australia including international teams and the top professional teams here as well. I can tell you heaps about tyres and temperature etc but it is really difficult to write everything here. If you are interested mesage me and I will tell you whatever you want to know.

[Red Dog]

I also run a 750 formula car. You will know when you are getting your tyres up to temperature without any help from a tyre temperature gauge. When you roll back across the stones in the paddock they will all stick fast. If this isn't happening then you are not going fast enough round the corners. Another clue will be that you will be lapping with the midfield runners (unless your engine is duff). If you find yourself near the front then you don't need any advice from me or anyone else!!

As a starting point....If your pressures are too high the centre of your tyres will be hot - too low and the edges will be hot. Too much negative camber and the inside edge will be hot - too little and the outside etc. etc. If they are not hot and sticky - brake later and start sliding it around!

By the way, I'm not rubbishing the gauges.

I am curious to know who told you that you could only generate 70 degrees max? Is the tyre the 811 Yoko?

[RWC]

Do they ise infared thermometer guns or built-ins to measure actual surface temp?

[Flatjack]

Red Dog,
Nice to meet someone else that is running in this formula What car are you running? I am currently building my car and hope to give it a run towards the end of next season.

I have spoken to Dick and a few others and they said that they do not get up to temperature so i went about getting information on the tyres to see what they should run at. In doing this i spoke to someone at Yoko Motorsport and he told me that they only got to about 70.

[racealign]

who did you speak to..out of interest?

[Flatjack]

I do not remember the name it was a few months back.

[Red Dog]

Hello Flatjack.
I am running a Centaur built (originally) in 1978

Hmmm....I have no temp gauge but my visual inspection shows the tyre is getting well above the point where it is getting soft and sticky. It is producing waste rubber (marbles) at a fair rate and the surface is graining very evenly across the tread. My experience is empirical rather than theoretical and I am relatively new to the driving bit. I have used softer slicks in a similar car and ruined the left front through overheating. Very costly.

It may well be that we are only at the lower end of the useable temp range but you know you've got them hot when you get home on Sunday night and the damn things have glued themselves to the trailer!

There are a number of things that will affect the temp as I'm sure you know, such as camber change on bump/roll, static camber, toe in/out, tyre pressure, wheel/tyre width ratio, springs, dampers, how late you leave your braking, how often you spin!!! One thing is for sure, if you manage to get them hot you will go a lot faster and once hot they won't lose their temp (unless you stop for a rest)

Hope you get your car finished soon and have a go at shredding your slicks! No good to you sitting in the garage.

[RWC]

Does anyone anywhere (f1 for example) use infared type lazers or similar to heat tyres on the go??

It's a neat idea isn't it?
SOMEONE will try it sooner or later!!