Losing rear grip over time. Thoughts?

[mdavistke]

Running Lime Rock on a 30 minute timed event with full chicanes with the M6GT3. I have adjusted the car using the David O'Reilly guide, can get specific if necessary. About 15 min into the race I have noticed that I am losing more and more rear traction, particularly on corner exit. I am using the Medium tires with stock pressures (22.5 psi I believe) and they seem to be in good shape at this point, but I need to check that closer. A friend of mine posited it could be fuel burn reducing the weight over the rear wheels, which seems plausible considering I start with just enough fuel to finish the race. Thoughts?

 

[stormychel]

Does moving brake bias forward make any difference?

 

[mdavistke]

Does moving brake bias forward make any difference?

I will try that tonight, however, it happens primarily on corner exit when I am not applying any brake.

 

[stormychel]

Yep, I don't know how detailed the tyre model is in RF2, but it seems to me that you are wearing your rear tyres out excessively by either applying too much braking force to them, or by slippage at corner exit?

 

[Emery]

Tire heat will increase tire pressure, possibly reducing available contact patch if initial pressure is too high. Can be confirmed by jumping to the garage when you notice loss of traction and seeing what the current tire pressure is vs. what you set.

 

[stormychel]

True. Does RF2 show wear at left, middle and right side of tyre?

 

[Case_]

The tyres on the S397 GT3 cars seem to be more sensitive to temperature rather than wear when it comes to grip. As in you can have almost no wear on them, but if you're heating them up too much, the will still have pretty low grip.

Also, be wary of too low rear downforce, that also can make your car very loose in the rear after a few laps.

 

[Ho3n3r]

The tyres on the S397 GT3 cars seem to be more sensitive to temperature rather than wear when it comes to grip. As in you can have almost no wear on them, but if you're heating them up too much, the will still have pretty low grip.

Also, be wary of too low rear downforce, that also can make your car very loose in the rear after a few laps.

Agreed. The tyres are very load-sensitive, and this also applies in weight shifts, i.e. braking/acceleration. Balance is the one thing you need to nail with the setup in order to have any confidence in rFactor 2. But it's very rewarding.

Not saying you didn't know this yet, of course - just my 2 cents. The tyre model in this sim is probably its standout feature.

 

[Ace King]

The tyres on the S397 GT3 cars seem to be more sensitive to temperature rather than wear when it comes to grip. As in you can have almost no wear on them, but if you're heating them up too much, the will still have pretty low grip.

Same thing happens in AC when temps get excessive! After a spin out you have nearly no grip at all and you feel like your driving on ice until tires cool off.

 

[Case_]

@Ace King Well, that obviously happens after a spin, but the thing is, with these cars in rF2, it can happen even if the temps are only slightly high, and after a few laps. You are driving and everything feels more or less fine and then a few laps later, your grip is suddenly gone.

 

[Ace King]

Exactly the same thing happened to me today (no spins) using AC at Spa 10 laps with track temps at 37C. Raced a Ferrari GT2 on "soft tires" which should be capable running a race stint. Perhaps a better tire choice would have been mediums to better control my tire temps or some pressure adjustments!