Slow Crash's RUF 86 BTR tune

85
United States
Miami FL
slow_crash101
Ok you noobs, listen up, this is a real man's car, and not everyone can drive it. That said, this tune helps somewhat alleviate the axe murderer nature of this car, but it will still kill you if you don't respect it. This tune works with or without a wing, however; if you plan on having this car over 530pp get a freaking wing.

The key to getting this car with some modicum of stability is the weight, and it's distribution. That's right, ballast. Remember this car is 1180kg from the factory, this is a car that was meant to weight 1300kg originally(when it was a Porsche), so yea a little bit of ballast helps. I do a stage two weight reduction, and ballast the car up to 1200'ish kg, which ends up being about 100kg worth of ballast. Now I know, you're probably thinking, it's stupid to do that, well I don't care what you think.

Put that ballast forward in the car I use from -24 to -26, the reason for this is simple, putting some weight over the front axle will make the car more stable going into and coming out of corners(and through sudden elevation changes). You add a bit of understeer, but it's better than spinning out every time you turn the wheel(plus now since you have stability you can actually use the throttle to help balance the car). Essentially you want to end up with a 43:57 front to rear weight distribution. This will also help load the front wheels while cornering, giving you better turn in.

Next, chassis stiffness, yea I know you don't think it helps but this car is old and flimsy, it needs all the help it can get.

So to recap on the chassis side

Stage 2 weight reduction + 100kg of ballast
43:57 weight distribution moving ballast forward 24-26 units
and install chassis bars.

For your power upgrades I leave that to you to decide.

Suspension tuning, the trick with the suspension is you want stiffer springs in the rear than in the front because that's where the weight is, that said you want a compliant rear end especially under acceleration, so that you can use the incredible traction afforded to this rust bucket. That said my suspension settings look a bit like this

Ride height Front: -18 Rear: -12
For some reason this car does not like to be lowered too much. I like to leave a 5-10 mm rake on the car, especially since I use relatively soft shocks in the rear.

Spring settings Front 8.8-9.4 depending on the circuit, the important thing is the ratio to the rear springs, which I have at 10.2-10.8, again depending on the circuit. I've found that stiff springs are needed to control the ballast you have put on the car. Don't worry, if anything these settings actually give you better tire wear, as you won't be spinning tires and sliding the car as much.

Dampers
Front 5(ext) 5(comp) Rear 6-7 (ext)(again circuit and driving style dependent) and finally 4 (comp), you could do 3 but I find it's a bit too soft for my liking.

Anti roll bars Front 4, Rear 3, I've found this is the best compromise to extract the maximum traction from the car, you may want to play with this value to match your driving style.

Alignment.
Remember this is a rear heavy car, so your alignment must match this.

I set front camber between 1.8-2.2 depending on what kind of tires I'm using. The less grippy the tires the less camber you can effectively use. In the rear I use between 2.0-2.4 usually about 2.3 it seems to be the best compromise between lateral grip and tire wear.

As for caster, you know the deal, negative in the front for turn in, remember this car will understeer a bit(just a bit compared to normal) now that you put ballast on the front, so you want to compensate by making the front react quickly to inputs, and letting the rear dance slowly around it. I use .-10 in the front and between .26-30 depending on track, and how I feel. This will further stabilize the rear, note the rear will slide no matter what you do but it can be controllable to the point of extracting delicious performance from it.

Finally the differential, my settings look something like this

Initial 16-18 (remember this is a turbo beast, and power delivery can be downright savage)
Acceleration 35-38, it's the best compromise between forward traction and acceleration out of corners.
Deceleration 25-27 <--very important to control the rear under braking, this car does have awesome brakes.

Finally a few tips on your driving technique.
a.)This car is like a temper-mental girlfriend, and if you treat her right, she will show you feelings you never thought were possible. Treat her wrong, and she will literally flip out on you.
b.) Never slam anything in this car(gas breaks steering), always be gentle, and anticipatory.
c.) You want to break first, then turn towards the exit of the turn not the apex, once the car is rotated and pointed at the turn exit, feed it power(gently).
d.) have fun and enjoy the new chest hair this car gives you.
 
you sound like you listened to the needs of this car, I may give it a whirl at the nur tonight.

note: a little OT, but a Lamborghini Gallardo, stock suspension, stock LSD, torque Distribution 10f/90r , only cosmetic upgrades like carbon driveshaft, and a flipped tranny to grind it's torque at 6,200 rpm to victory, on the Nur in under 7 minutes, taking some sections flat out that you were too afraid to do in other cars. (torque drops in high rpm, so keep that pedal mashed, lol)

to make the long story short, also has the same weight distribution 43:57, but I refrain from putting ballast toward the front. ever. it induces understeer even with this ratio set.

what are your brake balances set ^ ?
 
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the overall approach the OP has posted is a good one to tame this beast.

mine is tuned a little more aggressively (read it puts even more hair on your chest) and I'm at 6:55 @ 500pp on the 'ring (RS tires). i suspect this tune is easier (likely works a lot better with poorer tires than mine) to drive but a bit slower -- although in the case of this car, easier may mean faster ;)
 
I did the 560PP online TT at deep forest in a BTR for fun. What a nasty thing my tune was, only just good enough to gold.

I might try as many other BTR tunes as I can find soon. That might be good.
 
the overall approach the OP has posted is a good one to tame this beast.

mine is tuned a little more aggressively (read it puts even more hair on your chest) and I'm at 6:55 @ 500pp on the 'ring (RS tires). i suspect this tune is easier (likely works a lot better with poorer tires than mine) to drive but a bit slower -- although in the case of this car, easier may mean faster ;)

6:46 at 510pp on RS tires online with everything on sim
 
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