Novice tire question (E90)

[IamFODI]

Been running Michelin Pilot Sport 4S. Great tire for my skill level (i.e. low).

Even with close to the max possible camber with my setup, I'm still rolling the fronts a lot.

Would track tires mitigate that issue?

If so, any recommendations? I'd love something as communicative, noob-friendly, and long-lived as possible (in that order), with as little added grip as possible vs. the PS4S (don't want to hide my mistakes).

[Estoril]

What have your Instructors said on this issue and managing pressures? They have first-person experience in the car, know the wear habit vs. temps and know how you are (and aren't) working them.

[Slideways]

Been running Michelin Pilot Sport 4S. Great tire for my skill level (i.e. low).

Even with close to the max possible camber with my setup, I'm still rolling the fronts a lot.

Would track tires mitigate that issue?

If so, any recommendations? I'd love something as communicative, noob-friendly, and long-lived as possible (in that order), with as little added grip as possible vs. the PS4S (don't want to hide my mistakes).

I'm not a track expert, so can't give first hand experience. If you are not overheating the tire compound for the 4S other than the outer tread, maybe camber plates are a good place to start. Then if that doesn't improve the wear, next step would be to look at more HPDE oriented tires that have a stiffer sidewall like a Cup 2 or RE71R.

Edit: Forgot to mention tire pressures and that is probably the first thing to look at.

[Tbonem3]

RE71R

[timmo]

I was rolling the fronts on my Conti Extreme Contact Sport, camber plates definitely helped but the sidewalls are so soft - however the Michelins are a much better tire for the track than the Conti, with a stiffer sidewall.

If you're looking to switch to a dedicated track tire I'd recommend the Hankook RS4. It doesn't have the most grip for a track tire, but many amateur endurance teams run them, and for good reason - they wear like cast iron. The sidewalls are also very squared off compared to most street tires and are super stiff - for the Conti I've had to run closer to 40 psi, the RS4 sits happily at 28 psi hot

[IamFODI]

Thanks, everyone.

Estoril, my instructors were among the people recommending track tires.

Slideways, I've pushed the tires until they've chunked. Does that count as overheating? 😬

I've tried playing with tire pressure, all the way up to the max safe pressure. Not much improvement.

I do have camber plates. For some reason my alignment guy said he couldn't get much more than -2º out of one side so that's as much as I've tried. Honestly I find that assessment suspect as the plates are supposedly capable of much more, so I'll be getting a second opinion. I'm just trying to understand if track tires with stiffer sidewalls might help this particular issue as well. If so, I'd rather go that route.

[repoman89]

What does max possible camber mean in degrees? Some setups can get to -4 or less, some can only manage -2. You’ll probably want -3 to -3.5 degrees for track use (heavy macpherson strut car)

RS4s are great, but the PS4S should also be serviceable especially for a beginner, given the right setup and pressures. I ran them for a while before buying a square setup.

edit: posted before I saw that^. Well, I’d still consider a more aggressive front alignment along with listening to your instructors.

[bigjae46]

Stickier tires will make the issue worse.

The camber is going positive as a result of the lateral forces. You have a couple of options...

1. Add more negative camber
2. Increase tire pressures
3. Increase front roll stiffness

2 and 3 will cause understeer. Essentially you are reducing front end grip to reduce the positive camber gain.

Most alignment people have no idea how camber plates work. I would try about -2.5 to -3.0. The E9X M3s have a better control arm design so they don't need as much camber.

[Estoril]

By the way - cars I've instructed in tend to chunk PS4s when working the kerbs. Even the rough very edge of the kerbs. IME the shoulders don't like that transition edge and easily chunk. We tried fixing it with pressures and that had no effect. Did your Instructor try chalking the tire? I recommend that you chalk your tires, avoid the kerbs and see what the result is.

[heinzboehmer]

By the way - cars I've instructed in tend to chunk PS4s when working the kerbs.

People I know have had the same thing happen with PS4Ss. IamFODI , I'm not super surprised that your tires are chunking.

Agree with Jae, stickier means more rolling over. However, track tires should be able to manage the heat and stress better. Won't fix your rolling over issue, but should fix the chunking.

[IamFODI]

By the way - cars I've instructed in tend to chunk PS4s when working the kerbs. Even the rough very edge of the kerbs. IME the shoulders don't like that transition edge and easily chunk. We tried fixing it with pressures and that had no effect. Did your Instructor try chalking the tire? I recommend that you chalk your tires, avoid the kerbs and see what the result is.

This is probably a good point. I do tend to love the kerbs. 🤣

[Speed Monkey]

Draw from this what you will from Tire Rack’s testing of their crop of track tires they sell…. The BRZ, is at least front engine, and rear drive, the same as our M car. As for why the RT660 was highlighted, it is available in the 245-35-19 F & 275-30-19 R configuration. If one chooses this set-up, expect one’s wallet to be lightened by about $1,400.00 greenbacks. Good tires do not come cheap! The RT660 trails he leaderboard tire by less than half a second, or only .4 second, and it is the second place tire. For recreational users, this is probably good enough, but for the fellas looking for every last ounce of stick from their tires, then grabbing a copy of Grassroots Motorsports might be necessary because they do a nice job on covering which track tires does the best.

[Estoril]

I ran RT660s for one set after the RE71R became unavailable. The clag pickup was horrible and the car felt like the Fred Flinstone's car with the major clag vibration approaching apex. It simply sucked for the first two weekend events and gave the impression that there was a significant mechanical issue with the car. Tire Rack wasn't interested. Never again.

[Speed Monkey]

I ran RT660s for one set after the RE71R became unavailable. The clag pickup was horrible and the car felt like the Fred Flinstone's car with the major clag vibration approaching apex. It simply sucked for the first two weekend events and gave the impression that there was a significant mechanical issue with the car. Tire Rack wasn't interested. Never again.

Well then….

[Estoril]

Well then….

If you are intent on them, you might try having them heat-cycled.