Bottom Line: I'm struggling to get my Bridgestone RE71Rs up to optimal temperature in a Hillclimb and single lap sprint format, especially in colder temperatures.
Looking for a streetable tire that balances:
- cold and hot grip,
- warm-up time, and
- wet / rain capability.
Background...
I'm running a 2005 Mazda RX-8, about 2920 pounds with driver, in SCCA Hillclimbing, class DSP. I also use it for local autocrosses, and in the prior 3 years it was used for HPDE and NASA/SCCA Time Trials. But this season i wanted to try something different: Hillclimbs.
I am currently running 255/40/17 Bridgestone RE71R. I bought them "new" from discount tire direct at the start of the 2019 season, but they were mid-2017 date codes. I've done 2 track sprints, 6 hillclimbs, and about 6 autocrosses on them. Still have plenty of tread, which is nice (and surprising?). However, at the last hillclimb, with temperatures in the 70s and a tree-shaded mountain road, i wasn't able to get enough heat into the Bridgestones. I know, the autocross guys are thinking i'm crazy. But hear me out: at hillclimbs, i seem to build maybe even less heat in tires than autocross, because you're not turning as much (much more time spent accelerating), and you only get a single run and then cool-down for an hour. At least at autocross you're slaloming and scrubbing and having 3 runs somewhat back-to-back to build temps.
Almost all of the other folks are running Hoosier A7, BFG R1S, and other DOT legal autocross compound slicks. However, those folks are trailering their cars; i street drive my car to-and-from events. With the rollbar, i can no longer fit tires in the back seat, and i do not want to pull a tire trailer (i have no place to put it). So i street drive my "race" tires.
SO: I'm looking for a tire i can drive to-and-from events, that has a faster warm-up time than the Bridgestone RE71R, that has as much dry grip as possible while being capable of wet / rain racing. Tall ask, i know. I'll never have the stick of the slick guys, but at least i don't have to change tires when it rains or comes time to drive home.
I need to emphasize that it doesn't matter whether the RE71R is faster than a given tire with some heat and warm-up... if my conditions don't allow me to get the RE71Rs hot enough, it's not the best choice. I'm looking at tires that will maximize the AVERAGE grip over a short run, with no warm-up. It's possible my RE71Rs are too old calendar-wise and maybe heat cycled, because if i DO get runs close enough to retain some heat, i can feel i have more grip (substantiated by better runtimes ).
The requirements lead me to a short list of ideas for next season:
- Toyo R1R. This one has me thinking, hence the title of the post. Sure, it's undeniably anchient and outdated... but it works very well in rain and wet, and i believe it's very soft- it should have less heat up time than the RE71R, even if it doesn't build as much grip once heated. Basically, predictable grip from turn 1, while less grip than RE71R for the final few turns, but overall more average grip over the length of the run, and more predictable for the first few corners.
- Skinnier RE71R. With less contact patch and less rubber, it will heat more quickly and produce more average grip.
- Toyo R888R. Lots of folks in UK using for hillclimb and one lap sprints, and a friend who does time attack locally, says they have great grip from dead cold and have speed comparable to the RE71R.
Tires that i don't think qualify
- Conti ECS and MPSS / PS4. Just not enough dry grip. i have the contis and love their streetability, wet grip, predictability, and immediate cold grip... but i'm not sure they'd be competitive on a dry hill, even against a cold RE71R.
- BFG Rival S and Yokohama A052 or any other 200TW autocross tire, for the same reasons the RE71R isn't working well for me at the moment. They're designed to give good grip after a few runs, not neccessarily on run 1.
To give you an idea of what our Hillclimbs and Track Sprints look like, check out the videos in the playlist below:
https://www.youtube.com/watch?v=8tSuxNQZV0I&list=PLcwIM9WClgbEHbeTkdYaVUkvHR1r9bZmJ
At the Summit Jefferson Circuit, we get a warm-up lap followed by two flying laps... the RE71Rs always get to temp.
At the Summit Shenandoah Circuit, we launch from a standstill with zero warm-up for one lap. The RE71Rs barely get to temp.
At the Hillclimbs, especially in cooler temperatures, the RE71Rs never feel "sticky" like they do after a few circuit laps or after three autocross runs.
