I am trying to find information on the operating temperatures for the Cup2's and Dunlop RaceMaxx. I intend to take pyro readings on the next track day and would be very useful to have this information handy.

 

I would shoot for 36psi hot on all 4 corners with the Michelins. Be sure to use the circuit setting in the TPMS; it will reset every time you turn off the ignition and remove the key but for the session it won't freak out when your starting cold pressures are all over the place. While I haven't used the Dunlops you can probably run them at the same pressure. Sorry...I completely misunderstood your question and you want temp data not pressure data so I'm adding to my reply. Your temps will be based on how hard you drive, your hot pressures being in the optimal range and your ambient track temps. In a perfect world, no more than 20 degree jumps from inside to middle to out are what you want and camber is what will dictate that. If you have something like 20 degrees total difference inside to outside then call it a day and leave it alone.

You can't do anything really to target a certain temp overall other than making sure you're not under or over inflated.

For example, a front right tire that reads 220/200/180 from inside/middle/out would indicate a rather optimal camber setup but how hot it is and how hard you're driving are what generate the actual figures while camber dictates the relationship from inside to out.

 

Thanks for this. I have found 30-32F/33-35R give the best lap times. I have wing on high downforce, front duct blocks out, front sway on middle and rear sway on stiff. I have participated in 5 track days and have been able to improve my time significantly. I am asking about temps because i want to further improve my lap times. For the next track day at the end of this month i am doing alignment adjustment and fitting dunlops as my cup2's are more or less gone. I will be taking temps of the dunlops to ensure that the camber settings are working and also wanted to know the operating temps of the dunlops to better judge direction on tire pressure.

 

So many variables, but here are some input points I can share based on my experiences....

Dunlops RaceMaxx - my car came with Dunlops. You are the first person I've read who is considering changing from MSPC2s to Dunlops as most would prefer the Michelin. I have found Dunlops tires to be exceedingly good in terms of grip on the track, wear, and wet. My neighbor came back into the pits with a shredded MSPC2. Certainly, this is a single anecdotal experience but it did fail. I'll likely stay with Dunlops next tire change - as they say, "why fix what aint broke".

Temps - after coming in of the track and about 400 yards of cool down time to the garage, my temp gun showed the outside edge of the tires between 120 - 150 degrees.

Pressure Settings - at my first DE i set the tires 28 / 30 and rolled with it. When working with John at BGB I learned a different way of determining optimal air pressure - that is to make the goal to finish HOT air pressure the same in each tire, presumably to balance the load points. There are variables such as track surface, driving style and outside air temp. We started different cold air temps in each tire between 28 and 31 - looking for a consistent 36lbs hot when returning to the pits. Doing it this way, we were able to make small adjustments after the first session to achieve the desired goal.

 

After playing around with higher and lower, 35-36 seemed to work best for me at TWS.

At MSR Cresson, the guy parked next to me with a GT4 shod with Dunlops had completely shredded his front tires and large chunks of rubber, maybe 1-2" in diameter had ripped off in the center of the tire.

At TWS this past weekend, I experience something similar, but on the outside edge of my Cup2s.

I think with the stock alignment, pretty much any tire is going to have trouble surviving. The GT4 rolls too much in corners, so with it's strut style suspension, we're losing a lot of camber once it's loaded up. I think in addition to a proper alignment, we need stiffer sways to keep the car flatter.

This should probably go in another thread, but post 44 by pete is very informative on the downside of a Strut design vs. multi-link or wishbone on camber.

[insert planet 9 url here]/981-chat/103555-does-981-have-multi-link-rear-suspension-3.html

 

these psi's seem high !

 

Yeah, this "ideal track tire pressure" thread has already come up at least 2 other times in this section and the recommended hot pressure range seems to be as high as 36 and as low as 32 PSI. Part of the variation could be due to people wanting to strike different balances between perfect handling and outer tire wear, or maybe it's just different people's styles. I might also have attributed this to different skill levels given that the serious track junkies in the other threads seemed to consistently push for ~32 PSI hot, but here we've got John @ BGB recommending 36, so that doesn't seem to be it.

I think I'll start by targeting the higher end of the spectrum and adjust down as I feel may be necessary because I'd prefer to avoid shredding up a $2K set of tires at my first track event, even if it's only the front half. I'll also be getting an alignment sometime between my 1000-mile mark and my first track event since I read somewhere that AP says it makes a difference after the suspension settles and others have found their suspensions to be pretty far out of whack, which may also account for some of the tire shredding being reported if they didn't get an alignment after break-in.

 

This is just what I ran and liked but I think you could balance somewhere around 32 - 36 psi and still enjoy the car. As I have said, I like to set the car up perfectly with all settings in the middle so that when i move from track to track i have options of more or less. A range of pressures is better in case you want to balance the car and maybe go down with the front and up with the rear.

I ran 36 psi because the loads at Daytona are known for popping tires so I was careful not to let any students out with lower than usual tire pressures.
If I had more time and was not at Daytona I could have experimented with 33/37 to balance out the push more. Tire pressure is probably one of the most overlooked thing in Motorsport engineering.

Some people like lower and some like higher. By Sunday the exit push had disappeared so i left them be.