First thanks for a great overview. At 3:48 the slide states inside temperature should be hotter than middle which should be hotter than outside. Wouldn't this indicate too much negative camber with the inside of the tire working harder than the outside? I thought you want approximately even temperature across the tire to indicate the whole tire is working equally.
Good comment. Running negative camber the inside of the tire will be slightly warmer. If you could take instantaneous temperature mid-corner when the tire is loaded you should see equal temperature across the face of the tire, ideally (means you are maximizing the tires available grip). But since you spend more time going straight, the inside will be slightly warmer running negative camber. So if you come through the hot pit to take tire temperature the inside will be slightly warmer. The swing between inside edge to outside should be minimal, around 10F. Tire pressure also plays a role as we describe later. in the video Thank you for the comment and the Subscribe!
@@CallToGrid Thank you that makes sense. I am going to try to get some pyrometer data at autocross this weekend. If I can get out to measure quickly enough I hope it will tell me something. I'll also chalk.
@@CallToGrid First I had an awesome day of autocross! The course was just over a minute in duration with a long time between runs, so the tires did not get terribly hot. I started with pressures at 34psi front and 32psi rear using 245/40R18 and 275/35R18 Falken RT660s (200tw). Throughout the day I used a probe pyrometer after each run as soon as I pulled back into grid. As an example, tire temps for the front outside, middle, and inside were 115, 117, 118 deg F. Rear tire temperatures were in the low 90s. I found at 32psi the middle was a little hotter than the outside and the inside, so I dropped the pressure to 30psi and then they were very even across the face of the tire. I have a live axle out back. Up front I was running -1.5deg camber, +8deg caster, and 1/16th toe out. Each run the tire pressure would increase so I readjusted back down to 34FF/30RR and the temperature gradient remained similar. After the day of autocross, I can see the tire wear is very even across the face and extends just beyond the siping, not down the sidewall, so I think the pressures were good, but I'd love to hear more on the topic.
@@thebandit4393 I'm just seeing this reply. Sorry I didn't see it sooner. So cool to hear! Ok, we'll work on generating similar content. So happy we provided you value! Deepest sincere gratitude!
Haven't done any Karting but the principles should apply. Rubber meeting an asphalt surface. Temperature across the face of the tire would show you if you have correct tire pressures and camber. And tire temperature at each corner would show how each tire is generating heat. Could make adjustments from there. A scale would show how you have static weight distributed.
Crazy question? Why NOT have a tire cooling system INSIDE the wheel? In other words spray jets mounted in the valley of the rim directed at the inside of carcase? Yes I know it would require some kind of evactuation system to get the now hot water OUT....but I would think it instantly become steam in there so some type of high speed air pump could conceivably keep it evacuated WHILE at the same time via an ecu and sensors giving the car an active pressure control system! COULD even incorporate a tire WARMING system by initially blasting inside of carcasses with HOT steam! THAT could be HUGE in the opening lap? no? Then as race wears on tires could be kept at optional temp? I realize this is a highly complicated thing to engineer and would be expensive to develop and possibly no current way to make it light enough,,,,,but I know at least it COULD conceivably be done....of course there is the problem of absolute orifice seal on wheel changes as ducting would have to be faultless between pump outlets and wheel orifices
Normally keeping tires cool is not a problem. Optimally racing tires should be kept between 185-200F to be generating optimal grip. Cooling is only an issue on very hot days. You'll feel it! After a few hot laps you'll feel the tires giving way like there is a layer of butter or grease between the tire and the track surface. A very odd feeling, and you feel it. Design something up, collect data and you may have stumbled upon something.
Amazing vid
Very informative great job.
Thank you very much! I try and be quicker on replies. My apologies for not replying sooner.
First thanks for a great overview. At 3:48 the slide states inside temperature should be hotter than middle which should be hotter than outside. Wouldn't this indicate too much negative camber with the inside of the tire working harder than the outside? I thought you want approximately even temperature across the tire to indicate the whole tire is working equally.
Good comment. Running negative camber the inside of the tire will be slightly warmer. If you could take instantaneous temperature mid-corner when the tire is loaded you should see equal temperature across the face of the tire, ideally (means you are maximizing the tires available grip). But since you spend more time going straight, the inside will be slightly warmer running negative camber. So if you come through the hot pit to take tire temperature the inside will be slightly warmer. The swing between inside edge to outside should be minimal, around 10F. Tire pressure also plays a role as we describe later. in the video Thank you for the comment and the Subscribe!
@@CallToGrid Thank you that makes sense. I am going to try to get some pyrometer data at autocross this weekend. If I can get out to measure quickly enough I hope it will tell me something. I'll also chalk.
@@thebandit4393 Awesome! Let us know how it went!
@@CallToGrid First I had an awesome day of autocross! The course was just over a minute in duration with a long time between runs, so the tires did not get terribly hot. I started with pressures at 34psi front and 32psi rear using 245/40R18 and 275/35R18 Falken RT660s (200tw). Throughout the day I used a probe pyrometer after each run as soon as I pulled back into grid. As an example, tire temps for the front outside, middle, and inside were 115, 117, 118 deg F. Rear tire temperatures were in the low 90s. I found at 32psi the middle was a little hotter than the outside and the inside, so I dropped the pressure to 30psi and then they were very even across the face of the tire. I have a live axle out back. Up front I was running -1.5deg camber, +8deg caster, and 1/16th toe out. Each run the tire pressure would increase so I readjusted back down to 34FF/30RR and the temperature gradient remained similar. After the day of autocross, I can see the tire wear is very even across the face and extends just beyond the siping, not down the sidewall, so I think the pressures were good, but I'd love to hear more on the topic.
@@thebandit4393 I'm just seeing this reply. Sorry I didn't see it sooner. So cool to hear! Ok, we'll work on generating similar content. So happy we provided you value!
Deepest sincere gratitude!
Thx for the great vid. Very helpful.
So awesome to hear! Thank you!
Great video!
Thank you very much! If you have any subjects you'd like to learn more about, let us know!
What is the logic behind stiffening the hotter axle vs softening the cooler axle?
What was stated was to stiffen the end that is cooler. In general, a stiffer spring/shock will add heat to the tire.
Can we use these same concepts in a go-kart?
Haven't done any Karting but the principles should apply. Rubber meeting an asphalt surface. Temperature across the face of the tire would show you if you have correct tire pressures and camber. And tire temperature at each corner would show how each tire is generating heat. Could make adjustments from there. A scale would show how you have static weight distributed.
Crazy question? Why NOT have a tire cooling system INSIDE the wheel? In other words spray jets mounted in the valley of the rim directed at the inside of carcase? Yes I know it would require some kind of evactuation system to get the now hot water OUT....but I would think it instantly become steam in there so some type of high speed air pump could conceivably keep it evacuated WHILE at the same time via an ecu and sensors giving the car an active pressure control system! COULD even incorporate a tire WARMING system by initially blasting inside of carcasses with HOT steam! THAT could be HUGE in the opening lap? no? Then as race wears on tires could be kept at optional temp? I realize this is a highly complicated thing to engineer and would be expensive to develop and possibly no current way to make it light enough,,,,,but I know at least it COULD conceivably be done....of course there is the problem of absolute orifice seal on wheel changes as ducting would have to be faultless between pump outlets and wheel orifices
Normally keeping tires cool is not a problem. Optimally racing tires should be kept between 185-200F to be generating optimal grip. Cooling is only an issue on very hot days. You'll feel it! After a few hot laps you'll feel the tires giving way like there is a layer of butter or grease between the tire and the track surface. A very odd feeling, and you feel it. Design something up, collect data and you may have stumbled upon something.