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PhishHead
23-05-2018, 15:43
Hello all,
I've been working on the SLS recently, trying to find a set up which maximizes this car's strengths - yes, it does have some! :p - but am running into a problem across all tracks I am testing it on.
The main difficulty I am having with it, is the car likes to oversteer exiting corners, specifically low and medium speed corners. Essentially, the car will continue rotating in the direction of the turn when applying the throttle with any decent amount of pressure. For instance, Red Bull Ring, I am finding I am in the right barrier at turn 1, turn 2 (Remus), and heading right into pit lane at turn 7(Rindt). This is also happening frequently at turn 3 at Algarve as well, just for comparison (no barrier there, but you get my meaning). One of this car's greatest assets is acceleration out of corners - I'm not sure it has an equal in this class in that regard; I am leaving corners quicker, even at altitude, than the Ferrari - so, for one to need to "baby" the throttle to prevent oversteer negates this strength. I am trying to find a tune where this mitigation isn't so necessary. Perhaps it doesn't exist - in trying the newer AMG GT3 version I do not find this problem, but, conversely, it doesn't have the acceleration this SLS does - but thought I would ask the forum to see.

I realize this car isn't popular because it is older, perhaps difficult in handling, patches haven't been kind, etc...But perhaps, just perhaps, someone has run this car in a league and come to terms with it. Corner entry behavior is fine, mid-corner behavior is fine. Braking zones could use a little reduction, but I am willing to cede that is my fault and not the car's. But the oversteer is crushing, both for the car's body and my soul :D. This is the best I've come up with so far:

Tyres/Brakes etc...
Hard Slicks at all four corners:
FL/FR pressures: 20.89 PSI yielding approximately 26.00 PSI on track
RL/RR pressures: 18.85 PSI yielding approximately 24.00 PSI on track - I have not found a significant improvement in oversteer bumping the cold PSI to get 26.00 PSI on track
Brake Pressure: 93% (I have a the CSL Load Cell Pedal , with Brf at 30% for what that is worth)
Brake Balance: 60/40
Front Duct: 80%
Rear Duct: 70% (this leaves the rear brakes a little cold, can be reduced at higher alt tracks, I am also aware this will affect pressures)
Front Downforce: 2.00 (no speed difference between 1-2)
Rear Downforce: 8.00 (I have tried at 10.00 and 11.00 without improvement of the oversteer, but, max speed takes a hit which isn't what we are going for, ultimately, I'd like to get this down to between 4-6 if possible)
Long Weight Bias: 46/54 (I have tried 48/52, 47/53, and all the shades in between, without improvement of oversteer. Also tried 49/51 at Algarve and didn't help).

Suspension....
FL/FR
Camber Angle: -2.4 deg
Ride Height: 82 mm
Spring Rate: 260 N/m
RL/RR
Camber Angle: -1.8 deg
Ride Height: 87 mm
Spring Rate: 320 N/m
Front:
Toe-In Angle: -0.3 deg
ARB: 160
Rear:
Toe-In Angle: 0.0 deg
ARB: 24

Steering Ratio 10.0:1

Dampers....
FL/FR
Bump Stops: 5 mm
Slow Bump: 39200 N/m/s (maximum value) - This has provided some help, taking them to the minimum value makes the problem much worse
Slow Rebound: 39550 N/m/s (maximum value) - Same as above
Fast Bump: 6200 N/m/s
Fast Rebound: 12700 N/m/s
Bump Transition: 910 N
Rebound Transition: -1400 N
RL/RR
Bump Stops: 5 mm
Slow Bump: 23200 N/m/s (maximum value) - Same as above
Slow Rebound: 23550 N/m/s (maximum value) - Same as above
Fast Bump: 7000 N/m/s
Fast Rebound: 9600 N/m/s
Bump Transition: 930 N
Rebound Transition: -1420 N

Engine...
Radiator opening: 75% (this of course can also be reduced to add speed, but, unless I am mistaken, will have no affect on corner exit behavior)
Engine Braking: 6
Final Drive: 3.100 (I have made no adjustments to the Gearing)
Traction Control: 18% (Overall assist is set to Low in options, I am rarely seeing it kick in)
ABS: 80% (Overall assist is set to High)

Differential...
Clutch LSD
Preload 120 Nm (have tried as low as 80 without improvement)
Power Ramp: 60 deg (have tried up to 70 without improvement)
Coast Ramp: 30 deg (have tried up to 50 without improvement)

Stability Control is off.

If you made it this far, thanks so much for reading :o
Hopefully someone can try these settings and see if they are getting the same behavior. I am entirely open to the idea that I suck at throttle modulation :cool:
Also, I tried the set up which is listed in the post 5.0 set up thread for consoles which blink provided, the one for high DF at Nurburgring, and it was the same if not worse.

Any help is appreciated, thanks!

Zeratall
23-05-2018, 16:03
Drop the rear ride height, decrease rear arb, and increase the power ramp up to 90. Car should start to US on throttle. Then work your way down on the power ramp until it feels comfortable on corner exit.

PhishHead
23-05-2018, 17:03
Lol, that’s incredible. Thanks very much. US on throttle just as you said. Laps got extremely consistent very quickly.
Will begin working my way backwards.

Actually, this brings up a general question, which either yourself or others can chime in on:
To begin tuning this car, I started with making suspension and damper adjustsments around Indy Oval trying to find the quickest lap time, and once I found it, moved to a more balanced track (not RBR, that is just the track with which I felt I could describe the problem the best). I also tested different aero packages on the Oval to see what adjustments in downforce made to overall lap times. Then at the balanced track I started making brake and diff adjustments as well as monitoring tire temps and pressures.

Is that the best way to go about it? Not addressing the diff until later in the process? I ask because this moving the Power Ramp to 90 was a pretty drastic change in handling, and I wonder if people start there sooner?

Again, thank you!

Zeratall
23-05-2018, 20:15
Awesome glad it helped, as far my setup flow, I recommend watching this video I explain my process in these tune thst csr episodes. The intent is to show how I attack different behaviors the car is giving me.
https://youtu.be/6XBJY4m7_jc
Also I run a discord channel focused on tuning in project cars 2, we have about 100 members and it's a great way to get instant answers to your questions.
https://discord.gg/w2MeTey

KrypticTMG
24-05-2018, 15:12
https://www.youtube.com/watch?v=6LBRhGOVKDs

AbeWoz
24-05-2018, 15:48
https://www.youtube.com/watch?v=6LBRhGOVKDs

wrong car. he's in the 'old' SLS AMG GT3

hkraft300
24-05-2018, 16:48
Have you tried lower rear spring?
I just checked your spring rates (260 f 320 r) on Jussi’s suspension calculator and it’s giving me 1% front bias at 54% rear weight. I personally don’t like understeer yet I mostly run GT3 cars at 10-15% front bias and feel better balance at that rate. Some cars like the 650 won’t go below a ~30% front bias so it requires more aggressive trail braking to get the nose round.

Reckon softer rear springs would give you better balance on the SLS.

Zeratall
24-05-2018, 19:09
Have you tried lower rear spring?
I just checked your spring rates (260 f 320 r) on Jussiís suspension calculator and itís giving me 1% front bias at 54% rear weight. I personally donít like understeer yet I mostly run GT3 cars at 10-15% front bias and feel better balance at that rate. Some cars like the 650 wonít go below a ~30% front bias so it requires more aggressive trail braking to get the nose round.

Reckon softer rear springs would give you better balance on the SLS.
Good observation and recommendation.

KrypticTMG
24-05-2018, 22:39
wrong car. he's in the 'old' SLS AMG GT3

oh the old SLS haven't run it in a while but i'll be testing it soon at catalunya

hkraft300
25-05-2018, 01:17
Good observation and recommendation.

Would also have to raise the rear ride height if the springs are softened. To maintain rake.

How many clutches are on the diff?

I don’t recommend beginning a tune on an oval unless you’ll be racing at an oval only.

PhishHead
25-05-2018, 05:11
oh the old SLS haven't run it in a while but i'll be testing it soon at catalunya

Terrific! I read in one of the threads at AOR you didn't really rate the SLS as a viable option to run during a season, so wasn't sure if it would be a part of your current Catalunya series, so that's great news. I always enjoy and appreciate what you put up on your channel.

I really appreciate the suggestions everyone, I will try dropping the rear springs incrementally over the next day or two and report back, including raising ride height as I go along.

Hkraft - clutches are on 4 at the moment, will also adjust this up and see if there is any benefit.

And, Zeratall, I watched your McLaren tune today, that is wonderful stuff, definitely a different way to attack it with your software and you do a good job explaining what you are feeling as you go along, and why you are doing what you are doing. Wishing you much success with your software.

Atak Kat
25-05-2018, 05:31
I actually tried your setup in TT the other day at RBR. I see what you mean about T1 and T2 with the rear end. It is manageable if you have a delicate right foot, but it is really easy to get a little too excited with the go-pedal after the apex and then it's gone.

The problem was that I was doing pretty good lap times (for me, so approx 1:32ish), and any setup I changed either didn't help or got worse.
So just some comments and maybe I will learn something too. Things I thought while driving it.
- I kinda think part of the T1 (maybe also T2?) problem is that maybe your rear ride height is too low. It could be bottoming out somehow at T1. If you watch the telemetry you're rear is lower than front when at speed and I saw the rear go red a few times in T1.
- I think you can increase your rear camber (more negative). Although the rear tire temps stay pretty flat across the tire, I did notice that the outside temp would creep up to be 1 or 2 deg higher than the inside/mid temps.
- I reduced the TC slip to 9%. This made a big difference out of the turns, but my lap times suffered slightly
- I think your front tire pressures are too high. sorry for lack of psi, but I put the cold rear to 1.3 bar and front to 1.33 bar. I didn't see much diff in the cornering, but I found the braking much better and the fronts seemed to be grabbing better, instead of locking up.
- I assume you chose Hard tires for a reason. But in TT, by using Softs, almost all the issues you describe went away.
- I really don't understand the slow bump/rebound you have fully maxed out. this makes no sense to me, because if I understand correct it is basically preventing the car from shifting it's weight under braking/acceleration. Problem is, as you describe, I lowered it a lot but it didn't really change much. Maybe I should have lowered it even more. But i suspect some of the issue is here as well???

hkraft300
25-05-2018, 08:24
Dampers can act like dynamic springs. When they're too stiff for the springs, they'll stop the springs moving and take the load, making it feel like the springs are too stiff.
If the dampers are too soft, the spring oscillates and makes the springs feel too soft. So you end up chasing your tail.
Best to run it through zeratalls tuning program or jussi's suspension calculator and not adjust dampers blindly.

Also 4 clutches at 65į isn't a lot of locking, but can be depending on the power of the motor and gear ratios. 6 clutches will make the locking stronger. So more power oversteer.
That said, if the suspension balance is wrong I n the car, there's only so much you can do with the diff to mitigate it, and vice versa. Looking at the OP tune, I think the springs and dampers are the core problem and not the diff.

KrypticTMG
26-05-2018, 14:14
As promised the SLS setup, the car is a lot faster than i expected would be interested to see how it is in a endurance race.


https://www.youtube.com/watch?v=dPbSsFistIU

PhishHead
29-05-2018, 03:39
Wanted to just provide an update in case people search for info on this in the future:
I went back through the original values in the beginning of this thread, and I began making changes to the springs and ARB, ultimately settling on a pattern where springs were softer in front, around 260, and more stiff on the rear axle, around 280, with softening of the front ARB to around 100, and increase in ARB at the rear to the max of 24. I left the dampers alone. I also, based on Zeratall's suggestion, increased the power ramp to 90, and the car felt much better on corner exit; the oversteer was gone. Through many laps, I settled the power ramp around 75-80 which allowed me what I felt was good control on throttle coming out of turns. No more spins. Laps got very consistent, very quickly. However, nothing groundbreaking - I beat none of my records at the tracks where I care about such things. Also, it felt really good through the Bus Stop at Watkins, which is one of the ways I test a set up.

I then loaded Kryptic's set up, put the car on Algarve, and within 3 laps, had made a 1:46.xxx time which I'd never done before, in any of the GT3 cars, lol. I then went to Watkins. Turned a 1:45.5xx lap, also a record for me, and was getting 1:46's consistently. Then went to RBR - 1.31.355. I've been trying to break 1:32.xxx for more than a month. And I kept getting 1:31.xxx after 1:31.xxx after 1:31.xxx

What I really like about your setup Kryptic is the way this car enters a turn - the two back to back left handers in S2 at RBR, the sweeping right hander after the Bus Stop at Watkins, T's 3 (Lagos) 10 (Portimao) and T 12 at Algarve. Your set up is a vast improvement on anything I had in regards to corner entry, so thank you. It is also extremely stable under braking. What I had in my own setup thus far wasn't bad, but yours is better also in this regard. I have found lowering the DF ratio on some tracks is helpful depending on conditions, and I had to bump the power ramp up 75 in order to avoid spinning on corner exits at times. But as Zeratall has also pointed out in his tutorials, diff can be a very personal thing, and it's extremely likely you are better with the throttle than I am.

The times I listed above are shite, I know, but I wanted to pass them along because if I can turn these kinds of times with one night of getting used to this set up, you elite level drivers can certainly be competitive in this car. Just a couple of other anecdotes as I've been racing the SLS online this past week as well just to see:

1) My father and I were racing at Road America last night, he in the Ferrari 488 GT3 and myself in the SLS, and were using the front straight as a speed trap, we were both hitting 165 mph max before braking into Turn 1.
2) I found myself in a one-on-one race with the 'new' AMG this morning at Algarve, and the race was close for a good portion of it (until I spun, which I am liable to do, and why I don't join a league yet), but acceleration out of corners was better than the 'new' version. I think the AMG is a little faster in a straight line, but only just. Could have been setup differences as well I suppose.

Anyways, thanks again for all the help everyone. I will try the car out in a 50 lap race this week with Kryptic's set up, and see how it fares.

blinkngone
29-05-2018, 12:13
Wanted to just provide an update in case people search for info on this in the future:
I went back through the original values in the beginning of this thread, and I began making changes to the springs and ARB, ultimately settling on a pattern where springs were softer in front, around 260, and more stiff on the rear axle, around 280, with softening of the front ARB to around 100, and increase in ARB at the rear to the max of 24. I left the dampers alone. I also, based on Zeratall's suggestion, increased the power ramp to 90, and the car felt much better on corner exit; the oversteer was gone. Through many laps, I settled the power ramp around 75-80 which allowed me what I felt was good control on throttle coming out of turns. No more spins. Laps got very consistent, very quickly. However, nothing groundbreaking - I beat none of my records at the tracks where I care about such things. Also, it felt really good through the Bus Stop at Watkins, which is one of the ways I test a set up.

I then loaded Kryptic's set up, put the car on Algarve, and within 3 laps, had made a 1:46.xxx time which I'd never done before, in any of the GT3 cars, lol. I then went to Watkins. Turned a 1:45.5xx lap, also a record for me, and was getting 1:46's consistently. Then went to RBR - 1.31.355. I've been trying to break 1:32.xxx for more than a month. And I kept getting 1:31.xxx after 1:31.xxx after 1:31.xxx

What I really like about your setup Kryptic is the way this car enters a turn - the two back to back left handers in S2 at RBR, the sweeping right hander after the Bus Stop at Watkins, T's 3 (Lagos) 10 (Portimao) and T 12 at Algarve. Your set up is a vast improvement on anything I had in regards to corner entry, so thank you. It is also extremely stable under braking. What I had in my own setup thus far wasn't bad, but yours is better also in this regard. I have found lowering the DF ratio on some tracks is helpful depending on conditions, and I had to bump the power ramp up 75 in order to avoid spinning on corner exits at times. But as Zeratall has also pointed out in his tutorials, diff can be a very personal thing, and it's extremely likely you are better with the throttle than I am.

The times I listed above are shite, I know, but I wanted to pass them along because if I can turn these kinds of times with one night of getting used to this set up, you elite level drivers can certainly be competitive in this car. Just a couple of other anecdotes as I've been racing the SLS online this past week as well just to see:

1) My father and I were racing at Road America last night, he in the Ferrari 488 GT3 and myself in the SLS, and were using the front straight as a speed trap, we were both hitting 165 mph max before braking into Turn 1.
2) I found myself in a one-on-one race with the 'new' AMG this morning at Algarve, and the race was close for a good portion of it (until I spun, which I am liable to do, and why I don't join a league yet), but acceleration out of corners was better than the 'new' version. I think the AMG is a little faster in a straight line, but only just. Could have been setup differences as well I suppose.

Anyways, thanks again for all the help everyone. I will try the car out in a 50 lap race this week with Kryptic's set up, and see how it fares.

Cool PhishHead! Any sort of 1:31.XXX would be a top ten run at RBR in TT on PC.:cool: At Watkins Glen GP on PC the # 5 run is a 1:45.374 +0:00.641 so great again! Best thing is you are enjoying yourself and your progress with a car that is difficult for most people.