McLaren 650S GT3 trail braking problem

3,954
Philippines
Laguna
Alpha_Cipher1
I've tried various tunes for this car but there's always a consistent problem about trail braking. If I turn the wheel too much while trail braking the car would sort of slide a bit and correct itself. It's doesn't make the car undriveable but it does cost me 2-5/10ths of a second over a lap because of that. On most other cars this doesn't happen I can trail brake just fine. Can anyone give me a tune to dissolve this problem?
 
I'm currently trying to set up that devil car for a championship, and yeah the tyres really want to slide when releasing the brakes. I've worked mainly on my LSD setup as of now. Set your initial torque to the minimum and work up from there, test and increase by 5 until you reach the point when you stop sliding mid-corner. You'll probably still experience some sliding near turn-in point : do the same work again with initial torque to have the LSD lock up earlier. Do some timed laps each time, you'll notice a significant lap time increase when you go over the sweet spot.

I've done that just today, I feel like some fine tuning can improve it even more but that already made it more consistent on entries and improved my times compared to what I did with my previous setup when I started this practice session. When I have it completely refined, I'll try things on suspension then.
 
Thanks all for the tips! I haven't driven it recently because of those braking problems but I'm beginning to get back to it because ofthe advices. Thanks again :)
 
I've tried various tunes for this car but there's always a consistent problem about trail braking. If I turn the wheel too much while trail braking the car would sort of slide a bit and correct itself. It's doesn't make the car undriveable but it does cost me 2-5/10ths of a second over a lap because of that. On most other cars this doesn't happen I can trail brake just fine. Can anyone give me a tune to dissolve this problem?
The MC-12 is just the same, especially if your drive with traction off on standard control pad. I’ve tried shifting the Bias to the rear more but still have the same problem.
 
The MC-12 is just the same, especially if your drive with traction off on standard control pad. I’ve tried shifting the Bias to the rear more but still have the same problem.
Try the suggestion that GT_Alex74 gave. It's down to the LSD. I'm not quite sure how the new tire physics will react to this but it's your best bet for now
 
When you say the “front is sliding”, do you mean you’re getting understeer? If understeer during braking is your issues, try the following (1 at a time, not all at once)

• Adjust Brake Bias - number one tool for controlling understeer under braking is the brake bias. Shifting it forward will make the car more stable under heavy braking (and should decrease stopping distance) but will cause more understeer while trail braking. Too far forward and you’ll start locking the front brakes easily. Moving it rearward will make the car less stable under heavy braking, but will allow more rotation while trail braking. Too much rear bias and you’ll start locking the rear brakes. On many circuits it’s tough to find a balance that works in all corners, which is where dynamic brake bias adjustments come into play.

• Soften the front springs - softening front springs has the general effect of binging more grip to the front, leading away from understeer towards oversteer (note that only front springs effect braking through turn-it to apex, rear springs effect apex to corner exit). Going too soft with the front spings can cause the car to get tail happy under heavy braking, and get pitched violently into oversteer when you turn-in.

• Decrease LSD Braking Sensitivity - this setting controls the LSD under heavy to medium braking. If the car has a general under steering feeling under braking, and you don’t want to mess with the brake bias, this is the setting to adjust. The higher the number, the more stable the car will be under braking, but the less it will want to turn while braking.

• Decrease LSD Initial Torque (preload) - this settin effects the car when you are off both the brake and the throttle, or below roughly 10% of throttle/brake. As soon as you go more throttle/brake, the Accel/Decel settings take over. So the Initial Torque can have an effect during those split seconds when you are transfering from the very end of trail braking to beginning to apply throttle. If the car understeers in this moment, lowering the Preload can help combat this.

As a controller user, one area I have the most trouble with is being ultra smooth in that transition off the brakes, onto the throttle...I just don’t have the dexterity and travel in the trigger buttons to be perfectly smooth every time. The issue I always have is snap oversteer as I get off the brake, so I tend to run really high Preloads.

• Roll Bars - these have the largest impact on the car’s balance over the course of a whole cornering event. If the car has a natural understeer balance, softening the front bar, stiffening the rear bar, or both, will help remove the understeer across all parts of a corner.

• Dampers - this is where it gets tricky. Basically, springs control how much roll the car will have front to back, roll bars control how much roll the car has side to side, and dampers control how fast/slow that roll happens. If you’re car is under steering during trail braking, and you want to start adjusting the dampers, the first thing you have to determine is why the car is under steering - that is to say, is the understeer caused by too much weight being shifted forward too fast, or is it being caused by not enough weight shifting forward to slowly.

When you’re talking about the portion of the corner where you are braking, the two damper settings that come into play are the Front Compression, and Rear Extension. The front compression controls how fast the front end will dive under braking, while the rear extension will control how fast the rear lifts under braking.

Keep in mind that damper settings really only come into play for fractions of a second at a time - the instant you apply the brakes, the instant you transition from brake to throttle, etc. The dampers are really only in effect while the weight is being transferred.

So, if you determine that too much weight is going forward too fast, you can combat that by increasing the Front Compression. If not enough weight is going forward, you can decrease the Front Compression.

Personally I find that adjust Front Compression helps me solve understeer in the first half of the corner, while adjusting the Rear Extension can help control oversteer in the same part of the corner.


Hope that helps...not sure if you wanted this much info, but I was bored :lol:
 
When you say the “front is sliding”, do you mean you’re getting understeer? If understeer during braking is your issues, try the following (1 at a time, not all at once)

• Adjust Brake Bias - number one tool for controlling understeer under braking is the brake bias. Shifting it forward will make the car more stable under heavy braking (and should decrease stopping distance) but will cause more understeer while trail braking. Too far forward and you’ll start locking the front brakes easily. Moving it rearward will make the car less stable under heavy braking, but will allow more rotation while trail braking. Too much rear bias and you’ll start locking the rear brakes. On many circuits it’s tough to find a balance that works in all corners, which is where dynamic brake bias adjustments come into play.

• Soften the front springs - softening front springs has the general effect of binging more grip to the front, leading away from understeer towards oversteer (note that only front springs effect braking through turn-it to apex, rear springs effect apex to corner exit). Going too soft with the front spings can cause the car to get tail happy under heavy braking, and get pitched violently into oversteer when you turn-in.

• Decrease LSD Braking Sensitivity - this setting controls the LSD under heavy to medium braking. If the car has a general under steering feeling under braking, and you don’t want to mess with the brake bias, this is the setting to adjust. The higher the number, the more stable the car will be under braking, but the less it will want to turn while braking.

• Decrease LSD Initial Torque (preload) - this settin effects the car when you are off both the brake and the throttle, or below roughly 10% of throttle/brake. As soon as you go more throttle/brake, the Accel/Decel settings take over. So the Initial Torque can have an effect during those split seconds when you are transfering from the very end of trail braking to beginning to apply throttle. If the car understeers in this moment, lowering the Preload can help combat this.

As a controller user, one area I have the most trouble with is being ultra smooth in that transition off the brakes, onto the throttle...I just don’t have the dexterity and travel in the trigger buttons to be perfectly smooth every time. The issue I always have is snap oversteer as I get off the brake, so I tend to run really high Preloads.

• Roll Bars - these have the largest impact on the car’s balance over the course of a whole cornering event. If the car has a natural understeer balance, softening the front bar, stiffening the rear bar, or both, will help remove the understeer across all parts of a corner.

• Dampers - this is where it gets tricky. Basically, springs control how much roll the car will have front to back, roll bars control how much roll the car has side to side, and dampers control how fast/slow that roll happens. If you’re car is under steering during trail braking, and you want to start adjusting the dampers, the first thing you have to determine is why the car is under steering - that is to say, is the understeer caused by too much weight being shifted forward too fast, or is it being caused by not enough weight shifting forward to slowly.

When you’re talking about the portion of the corner where you are braking, the two damper settings that come into play are the Front Compression, and Rear Extension. The front compression controls how fast the front end will dive under braking, while the rear extension will control how fast the rear lifts under braking.

Keep in mind that damper settings really only come into play for fractions of a second at a time - the instant you apply the brakes, the instant you transition from brake to throttle, etc. The dampers are really only in effect while the weight is being transferred.

So, if you determine that too much weight is going forward too fast, you can combat that by increasing the Front Compression. If not enough weight is going forward, you can decrease the Front Compression.

Personally I find that adjust Front Compression helps me solve understeer in the first half of the corner, while adjusting the Rear Extension can help control oversteer in the same part of the corner.


Hope that helps...not sure if you wanted this much info, but I was bored :lol:
Great information for tuning. Thanks for sharing. :cheers: You might have made some new tuners out here. I am inspired as well.
 
Back