Tire temps and pressures ... case study

darock · 20 March 08, 13:54

I was just starting to run the Vauxhaul. Went to Brands Hatch for the first runs as I know it. After one test run of 8 laps, I adjusted the camber and pressure and ran another test run of 5 laps. At the end of that 5 lap run the temps across the tires were pretty good and the temp difference inside-to-outside was very close. But I need to do one more round of slight adjustments. Here are the temps, both F and C

F temps:

182/189/194 -- 178/174/167
163/168/173 -- 152/147/143

C temps:

83/87/90 -- 81/79/75
73/76/79 -- 67/64/62

darock · 20 March 08, 14:00

Lets look at the FL tire.

It shows 182/189/194 F temps and 83/87/90 C temps.

The inside-to-outside temps show a touch too much negative camber.
The center temp shows the pressure is a bit too high.

I'd like to see something more like 183/188/193F or 182/187/192F

So I'm going to take a click of camber out and a click of pressure out.

darock · 20 March 08, 14:05

Looking at the RL tyre:

It shows 163/168/173 F temps and 73/76/79 C temps.

It's good to go. No changes.

The track is a clockwise track. The left side tyres are the really important ones. You can keep the setup symmetrical and simply work what you see for the lefts. Or you could work each tyre individually by changing the setup option to independent. It's quicker to work just one side, but make sure you work the hot side.

darock · 20 March 08, 14:13

BTW, in my 2nd test run, the 5 lapper, the car was doing lap times within about a second of what I can do in the other cars. Not good? Well, I hadn't touched the gearing yet.

I adjusted the gearing when I tweaked the tyres after that 2nd run. And in the 3rd run the car was within tenths of what I can do in the other cars.

The tyre camber/pressure got me in the ball park on handling and the gearing adjustment capped it off.

Now I can screw around with springs or shocks or such and know that it'll be worth the effort.

Roberto Sagessi · 20 March 08, 18:43

Got it!...once again very clear professor! I have a brake question for over in your other setup thread...don't want to cross post here.

darock · 12 April 08, 18:20

Is any of this worthwhile?

I just did a test of the default setup (one size fits all) against one that only had the cambers, pressures, and gearing rough tuned. It was a blind test. That is, I didn't know I was running the default. Truth is, why the favorite wasn't loaded is a good question, but it was online and damn near anything happens online.

I instantly felt that the front was understeering extraordinarily but soldiered on. After a couple of timed laps, I'd had enough and went into the garage to discover the favorite hadn't been loaded. Loaded it and had just enough time to get one timed lap before qualifying was over. Moved from the middle of the grid to 3rd. Out of 22 drivers online, that matters. Online you need to be in the front rows. From about row 3 back to the last couple of rows you might as well log out. You're going to be hit unless you've got a couple of cars behind to take the shot, or you're far enough back there won't be but a couple behind you.

I got no idea why those guys don't figure it out. Cars further back in the grid have longer to accelerate and need to brake BEFORE the cars ahead brake. Because they're going to be going faster than the cars ahead. whatever..........

Roberto Sagessi · 14 April 08, 06:50

Well I've switched to the Radical sr4 252 and 205 (depends on the track and power needed) and once again I have to tahnk you for your setup tips. For the 252 I have a basic setup that I load and tweak for each of the tracks I've been running. I find that the Rads are very easy on the tires for some reason and the temps don't range too far outside to inside...so I'm mostly working with pressure to tweak the inside temps. I've found myself now working on brake balance, springs, swaybar and wing as the next step to eak out a bit more. I haven't been logging as much track time so the driver is the biggest thing right now...but I do love the RADS...POWER AND HANDLING=FUN! Really a great car for the Interlagos track posted here recently.

20 March 08, 13:54	#1
darock Moderator Join Date: Nov 2006 Location: North Carolina	Tire temps and pressures ... case study I was just starting to run the Vauxhaul. Went to Brands Hatch for the first runs as I know it. After one test run of 8 laps, I adjusted the camber and pressure and ran another test run of 5 laps. At the end of that 5 lap run the temps across the tires were pretty good and the temp difference inside-to-outside was very close. But I need to do one more round of slight adjustments. Here are the temps, both F and C F temps: 182/189/194 -- 178/174/167 163/168/173 -- 152/147/143 C temps: 83/87/90 -- 81/79/75 73/76/79 -- 67/64/62

20 March 08, 14:00	#2
darock Moderator Join Date: Nov 2006 Location: North Carolina	Lets look at the FL tire. It shows 182/189/194 F temps and 83/87/90 C temps. The inside-to-outside temps show a touch too much negative camber. The center temp shows the pressure is a bit too high. I'd like to see something more like 183/188/193F or 182/187/192F So I'm going to take a click of camber out and a click of pressure out.

20 March 08, 14:05	#3
darock Moderator Join Date: Nov 2006 Location: North Carolina	Looking at the RL tyre: It shows 163/168/173 F temps and 73/76/79 C temps. It's good to go. No changes. The track is a clockwise track. The left side tyres are the really important ones. You can keep the setup symmetrical and simply work what you see for the lefts. Or you could work each tyre individually by changing the setup option to independent. It's quicker to work just one side, but make sure you work the hot side.

20 March 08, 14:13	#4
darock Moderator Join Date: Nov 2006 Location: North Carolina	BTW, in my 2nd test run, the 5 lapper, the car was doing lap times within about a second of what I can do in the other cars. Not good? Well, I hadn't touched the gearing yet. I adjusted the gearing when I tweaked the tyres after that 2nd run. And in the 3rd run the car was within tenths of what I can do in the other cars. The tyre camber/pressure got me in the ball park on handling and the gearing adjustment capped it off. Now I can screw around with springs or shocks or such and know that it'll be worth the effort.

20 March 08, 18:43	#5
Roberto Sagessi Join Date: Jan 2008	Got it!...once again very clear professor! I have a brake question for over in your other setup thread...don't want to cross post here.

12 April 08, 18:20	#6
darock Moderator Join Date: Nov 2006 Location: North Carolina	Is any of this worthwhile? I just did a test of the default setup (one size fits all) against one that only had the cambers, pressures, and gearing rough tuned. It was a blind test. That is, I didn't know I was running the default. Truth is, why the favorite wasn't loaded is a good question, but it was online and damn near anything happens online. I instantly felt that the front was understeering extraordinarily but soldiered on. After a couple of timed laps, I'd had enough and went into the garage to discover the favorite hadn't been loaded. Loaded it and had just enough time to get one timed lap before qualifying was over. Moved from the middle of the grid to 3rd. Out of 22 drivers online, that matters. Online you need to be in the front rows. From about row 3 back to the last couple of rows you might as well log out. You're going to be hit unless you've got a couple of cars behind to take the shot, or you're far enough back there won't be but a couple behind you. I got no idea why those guys don't figure it out. Cars further back in the grid have longer to accelerate and need to brake BEFORE the cars ahead brake. Because they're going to be going faster than the cars ahead. whatever..........

14 April 08, 06:50	#7
Roberto Sagessi Join Date: Jan 2008	Well I've switched to the Radical sr4 252 and 205 (depends on the track and power needed) and once again I have to tahnk you for your setup tips. For the 252 I have a basic setup that I load and tweak for each of the tracks I've been running. I find that the Rads are very easy on the tires for some reason and the temps don't range too far outside to inside...so I'm mostly working with pressure to tweak the inside temps. I've found myself now working on brake balance, springs, swaybar and wing as the next step to eak out a bit more. I haven't been logging as much track time so the driver is the biggest thing right now...but I do love the RADS...POWER AND HANDLING=FUN! Really a great car for the Interlagos track posted here recently.