Tuning a differential in Formula Renault 2.0

[hispanicpanic]

Looking to get some insight into how i should tune my FR 2.0 in the sim and i'm having a hell of a time getting the rear diff right.

Ramp angles available are 65/70 or 70/65 with preload ranging from -100 to +100 ft/lbs. I cannot do 70/70 or 65/65. Which is a total bummer because i'm used to open diffs and relatively loose LSD's on production vehicles. using a 65 on accel and 70 on decel makes turn in nice and taking hairpins at tracks like cota are nice and easy, but acceleration is a bear. Just a tiny amount of wheelspin on throttle is difficult to recover and the rear end of the FR 2.0 already feels like its on ice. I've since been using 65 on decel and 70 on accel because powering out of the hairpins is much more consistent, but of course that comes with another problem. Trail braking is now a bear and in a high speed braking zone i sometimes swap ends if the rear end locks on turn in. I'm not a terrible driver by any means, i'm consistently 1 or 2 sec off pace from the fastest dudes in the series, but this is my first time tuning a 2 way differential and i'm at a loss on where i should begin.

Another note, adding a bunch of preload on 65 decel and 70 accel seems to tame the diff during off throttle maneuvers a bit more, of course it comes at the cost of a tighter diff on acceleration. So i'm always having to trade off performance characteristics and have yet to find the best medium.

[Jersey Tom]

Ramp & clutch diffs can be immensely powerful tuning tools in real cars, and in simulation if they're modeled accurately.

With that said, you don't exactly have much to tune with there if your options are only 65/70 and 70/65, so I wouldn't spend too much time debating. Pick one, and tune the rest of the car around its limitations. Like if you're locking a rear tire on braking, well... go for more front brake bias. Or if you're struggling with power down, can always put more roll stiffness in the front end compared to the back.

[hispanicpanic]

Good points. Really not liking 2 way differentials. In my opinion, a 210 hp motor has no business running a clutch pack differential, it just creates more problems and is undoubtedly slower.

I've settled on the 65 drive and 70 coast ramp angles with approx 15 lbs of positive preload. I've also had to change my driving style to be slower on turn in and have eliminated trailing if at all possible. This seems to be the only way to achieve stability in this car without sacrificing high speed coasting/braking balance.