Is it worth having a pyrometer for GS? There is not much camber adjustment so the outside of the tires will be much hotter than the inside and I am not sure what I would be looking for.

I want to find the best tire pressures. I am using Kumho 215/40/16 and have used front from 38-42 and rear in the 47-50 range. The difference in rotation is clear but I am not sure which pressure is really giving the best grip and am wondering if a pyrometer would help.

Suggestions?

 

Yes it would, as you could actually check the temps for front to rear and side to side differences. This will assist you in setting the car up for each track.

 

What do the readings look like when the car is correctly set up? How should the temp of the middle of the tire compare to the inside and outside when there is insuffient camber? Does the temp of the rear matter if the rear pressures are chosen for rotation?

Also, what is a good inexpensive pyrometer?

Thanks

 

The readings are going to be determined by your tires and set up. I don't have a lot of experience with cars that don't have some kind of camber adjustment, so I don't know how that would affect your car. I would guess that you would want to try and have consistent temps across the tread with or without camber adjustments.

You will be able to match temps side to side and front to rear on the car by adjusting pressures. This wil help with tracks that might tend to be more right or left hand turns. And you will be able to make sure that the temps are not getting to high in the rear so you can extend their life.

Sorry I couldn't be more help, maybe someone with more experience will post.

 

But without the camber adjustment there would be no way to get the outside and inside consitent - the outside will always be much hotter. Should the middle be around the average or nearer the temp of the outside?

Also, when you are using tire pressure to get rotation, do you still expect the rear to be consistent with the front?

 

Keith,
On my car with the V710 I ran around 42-44 psi. Unfortunately with our camber challenged cars we sometimes have to run a slightly higher then optimum tire pressure to keep off the shoulder. I don't own a pyrometer but have used one at an event and found that at that pressure the inside and middle were at the same temperature and the outside was 10-15 degrees hotter. The is nothing we can do about that except to cool the shoulder of the tires between runs when it is hot out.

 

The fronts and rears should be nearly the same temps, but you can have them at whatever you feel comfortable with. You can them make sure they are consistent with the pyrometer.

 

Yes, tire pyrometer is good and useful for any performance driving from autocross to track or high performance driving school.

There are two types- probe and Infrared. The probe is more reliable and reads the temperature from the rubber when the metal probe is inserted into the tire. Infrared is reading temperature off the surface of the tire.

Since G stock doesn't allow much for camber adjustment do not expect much from your tires for an even tire temperature spread. Normally under hard driving your front tires will heat up fast and your back tires will be essentially 20 degrees colder. Depends on your event length and how many runs and time of rest between runs as well as course surface and outside temperatures.

Your tires will be hottest on the outside front edges. Adjust your tire temperatures to get the middle front tread readings as close as possible to the outer edge readings. The inner edges will be cold due to lack of front negative camber.

Rear readings can be similar with coldest on the inner edges and hotter on the mid and outer sides- adjust temperature accordingly to try to even out the readings.

Do not expect the first run to heat up the tires- it can take 2 or 3 runs to get the temperatures up then leave them alone. If you use street tires they might heat up quicker than R compound tires. Each tire is different and driver skill and course design are factors as well.

It's also always good to chalk the tires for roll over onto the sidewalls as there is only so much rollover you want- use all of the tire but don't overdo it.

Hope this helps. What works for one person is different for another even with the same tires and same type of car. Higher speeds heat up the tires faster. Suspension upgrades help to make better use of the tires.

You use the pyrometer to allow you to adjust tire pressures to get the most out of your tires. If you do have an adjustable suspension you can use the pyrometer to determine alignment settings that work best for tire wear. But that would not be a stock MINI.

 

A great read about pyrometers. Be sure to read section G (IR vs. Probe):
http://www.hmsmotorsport.com/docs/Pyrometer_Tips.pdf

As far as prices,

Here's an economical probe type ($98.15) :
http://www.racerpartswholesale.com/p...cre_Pyrometers


And another from a local buddy of mine ($99.95):
http://www.turbojohn.com/mall/index....roducts_id=332




A good IR laser ($69.99):
http://www.hmsmotorsport.com/store/t...ire-pyrometer/


Most compact and cheapest IR I've seen ($34.99). I have seen cheaper, but their range only goes up to about 230F, this one goes up to 482F:
http://www.jegs.com/p/Micro-Temp/Spa...60614/10002/-1


This is pretty trick - two in one! And it's only $186.12:
http://www.racerpartswholesale.com/p...455/Pyrometers