What to do when cooking rear tire at Cape Ring?

[chuyler1]

Load up Cape Ring North or Cape Ring Periphery in a ~450 PP FR/MR/RR car on sport soft tires. Run wide open throttle on the uphill loop. The outside drive wheel slowly builds heat and eventually let's go sending you spinning into the guard rail.

I'm sure others have come across this issue before and I'm wondering what suspension or LSD settings will help resolve the problem. The car I'm having trouble with particularly is the Ruf BTR.

I have messed with the LSD but it doesn't seem to make a difference. I have also tried increasing rear camber in hopes that it will give that tire a little more grip. Nothing seems to show progress so I am forced to half-throttle the turn and work the steering wheel to compensate for the twitch oversteer that just won't go away. It just seems like throttle+turning is a bad combo in this car even if you provide smooth steering inputs.

 

[GrimSinn]

Yeah the 86 BTR is a Beast, even in stock trim. You might be experiencing the limits of Sports tires on a BTR however There are a few things you can do to stop roasting the inside tire, keeping in mind its tough to tune through a forum ill try to help.

Reducing the LSD accel from 40 to around 30 even lower if you have to can greatly reduce roasting of the inside tire in corners. Also camber/toe settings can be adjusted to help. If your experiencing this in the banked turn try bringing up the rear camber setting or reducing it (playing with the contact patch). Some positive toe /more or less could also get the inside wheel on a more friendly path.

Then again WOT in a BTR riding a banked corner on Sports Tires is a scary thought. lol

 

[chuyler1]

Good suggestions, I am already running low LSD settings and the inside tire appears to behave ok. I played with some minor camber changes but I'll spend a little more time in that area. I'll also play with the toe.

 

[GrimSinn]

Good suggestions, I am already running low LSD settings and the inside tire appears to behave ok. I played with some minor camber changes but I'll spend a little more time in that area. I'll also play with the toe.

No Prob, good luck with the tune. It's a tough car to balance no doubt.

 

[Ronald6]

Spring rates come to mind, perhaps the back end is too stiff or too loose? If the tyre is slowly heating up the problem may be improper weight distribution, and to me that means springs. RH might help but I usually use that to adjust the cars PMI once its close to its sweet spot.

 

[CyKosis1973]

Any of the above suggestions might help. However, with this particular track though, you need to keep the car in the centre of the tarmac. If you drift too near the bottom, the car becomes unbalanced due to the uneven surface. The inside line of the bend is flat, put a front wheel on it and you'll lift the front left and rear right tyre. That's my opinion anyway. I've driven hundreds of miles in the Lion's Den Commodore and it drives beautifully. Take it around this particular bend and let the front inside tyre drift down onto the flat inner line and it’ll kick the rear end out.

I'll wind my neck in if you're having trouble higher in the bend...

{Cy}

 

[oopssorryy]

The best I've done on Sports Softs was 107ish in my MR2 G 1600 Turbo. My main issue is I can't hold a steady line though out the corner, but that's what I get for using a DS3. I do agree with CyKosis1973, go to low and you'll hit the tracks apron. Doing this will result in a loss of traction and it usually pushes me wide. I've never had a problem with my outside tire burning up though. I'll be posting a re do of my two MR2 tunes later today, and I would love if you would give them a try.

 

[CyKosis1973]

You have to keep it parallel through this corner, if you come in too high and then try to dip the nose in to a more central line, the same thing will happen before you hit the exit. The only thing you can do, without fear of the car switching ends, is lift off.

All that being said, I could be talking rubbish and it maybe a problem with the OPs setup...

{Cy}

PS - oopssorryy, was that 1:07 on the North track..?? I'm gonna hafta check my times around there now :-P

 

[oopssorryy]

Hahaha I wish, no I was talking about my speed though the corner on Sports Softs, I guess I should have said that. The MR2 setup I'm running right now can take slow lift of with no problems, that's what I usually end up doing. I almost always run wide at the end, and have to lift off until I'm traveling around 95-105 which is frustrating, but the only fix for it is practice, practice, and more practice

 

[chuyler1]

Thanks for all the suggestions. I'm well aware of the apron issue and I always stay clear of it. I typically run in the center of the track or a little inside, but never close enough to touch the apron.

In some of my other cars I can hit 105-107 but the BTR's limit is somewhere around 97 mph. I can run faster but the tire heats up and I have to drop to 90 mph to let it cool. Other cars just pull away from me.

I ran the BTR last night and although challenging, it behaves very well on other tracks. If I get time today, I will experiment with spring rates and rear rollbars. I'll try a few different camber settings but I know for a fact if I go much lower in the rear it will hurt my exit speeds. Less rear camber = more exit oversteer.

Anyway, while we're on the subject, here's one exciting race from last night's '80s night. The BTR is the king of late braking but with only 450pp it loses some grunt coming out of the turns. The final turns of the race reveal how too much throttle will still cause oversteer. Speed in this car comes from holding back and waiting for the apex. I was not awarded for aggressive driving and spun the tires instead of slingshotting past the Silvia. Nic in the Silvia, is an excellent driver and we battled all night long.

 

[oopssorryy]

Hmmm With the BTR i would try raising rear Spring rates, or raising rear Damper Compression. I think the BTR is burning the tire because of it's RR setup, and with the G forces on the Loop, I think your outside tire is loosing traction and spinning, causing it to burn, and when you ease of that tire regains traction and attempts to kill you.

This is all just me thinking, and I hope it helps you.

Edit: Could also increase rear Anti Roll Bars, don't know why I didn't think of that before...

 

[Ronald6]

Edit: Could also increase rear Anti Roll Bars, don't know why I didn't think of that before...

^^ this.

I was thinking about it at work and realized the roll bars would have a larger effect with the problem you are experiencing. If its setup correctly the roll bars should help to keep both tyres pushed against the ground equally. Your bars could be too strong or too weak. Then again they might be just right and the ouside burn is something you'll have to live with.

 

[chuyler1]

I think I have them at 3/4 front/rear. First thing I'm going to try is 3/5 or perhaps 4/5 since I do have ballast in the front and I don't want to large a difference.

 

[Adrenaline]

Define what you call 'low' LSD settings.
What are the actual numbers you're running for Init/Accel/DeAccel?
I'd also be curious of your downforce values used for cape ring (and the max allowed)?

 

[oopssorryy]

I have a set up on my GT-R of 2/6 and it works rather well, so you might try 3/6 as your front end is behaving nicely. (These are Anti Roll Bars)

 

[chuyler1]

Define what you call 'low' LSD settings.
What are the actual numbers you're running for Init/Accel/DeAccel?
I'd also be curious of your downforce values used for cape ring (and the max allowed)?

LSD somewhere around 8/36/18 (don't quote me on that cause I don't have the game running in front of me). No issues spinning the inside tire but I think after watching that replay above I could raise the LSD a little so I don't have to be so light on exit throttle.

No downforce since I use the car for Performance Point racing. Any point toward downforce is a point away from straight line power. If I can tune the car without a wing, I'll do it.

 

[oopssorryy]

When My MR2 G 1600 oversteered on corner exit I jacked up the acceleration sensitivity. Right now it's up at 44, and if I'm not a complete idiot in the turns, I can keep the back end in line. What I'm trying to say here is I think your on the right track, and I really like my MR2s!

 

[Adrenaline]

LSD somewhere around 8/36/18 (don't quote me on that cause I don't have the game running in front of me). No issues spinning the inside tire but I think after watching that replay above I could raise the LSD a little so I don't have to be so light on exit throttle.

No downforce since I use the car for Performance Point racing. Any point toward downforce is a point away from straight line power. If I can tune the car without a wing, I'll do it.

As a quick and easy test, tonight when you get home, drop your LSD settings to 5/5/5. Run it up that corkscrew full throttle, keep an eye on which tire heats up first before breaking traction. If nothing changes, then the issue isn't in the LSD and you can focus on suspension adjustments instead.

If you refuse to use downforce, have to live with lower cornering speeds. Downforce adds PP for a reason. The faster you want to turn, the more downforce is required to hold you to the track.

 

[chuyler1]

As a quick and easy test, tonight when you get home, drop your LSD settings to 5/5/5. Run it up that corkscrew full throttle, keep an eye on which tire heats up first before breaking traction. If nothing changes, then the issue isn't in the LSD and you can focus on suspension adjustments instead.

Well I know right now its the outside tire, but I'll run this test as well. If it were the inside tire, I would've automatically assumed some sort of LSD change was in order.

If you refuse to use downforce, have to live with lower cornering speeds. Downforce adds PP for a reason. The faster you want to turn, the more downforce is required to hold you to the track.

I know I know. But as of right now I don't need the downforce on any other track...and the wing looks silly on this car.

 

[Adrenaline]

Well I know right now its the outside tire, but I'll run this test as well. If it were the inside tire, I would've automatically assumed some sort of LSD change was in order.

I know it's the outside tire 'now' I want to know which tire it is when using the 5/5/5 test.

 

[chuyler1]

ahh ok. well i'll report back soon.

 

[chuyler1]

I've got 30 minutes so here goes...

Initial settings which have been working on other tracks...
Ballast: 100kg at -50
Engine power limit: 75.1% (for 450pp racing)
Transmission: 174mph top speed
LSD: 20/40/20
Height: 0/0
Spring: 9.5/10.0
Ext: 6/6
Comp: 6/6
Roll: 4/5
Camber: 0.0/1.5
Toe: 0.00/0.20

Log:

First off, problem doesn't even occur in practice mode. Had to go into an online lobby. Boy is that lame.

Tried LSD at 5/5/5. Car became way loose but I could hold full throttle at about 105mph. Tires did not overheat though.

Tried LSD at 10/20/20 and went back to cooking outside tire. Ugh.

Tried 10/10/20 and still cooking.

This is going to take some more time. I will post again when I have more time to mess with it.

 

[Adrenaline]

I've got 30 minutes so here goes...

Initial settings which have been working on other tracks...
Ballast: 100kg at -50
Engine power limit: 75.1% (for 450pp racing)
Transmission: 174mph top speed
LSD: 20/40/20
Height: 0/0
Spring: 9.5/10.0
Ext: 6/6
Comp: 6/6
Roll: 4/5
Camber: 0.0/1.5
Toe: 0.00/0.20

Log:

First off, problem doesn't even occur in practice mode. Had to go into an online lobby. Boy is that lame.

Tried LSD at 5/5/5. Car became way loose but I could hold full throttle at about 105mph. Tires did not overheat though.

Tried LSD at 10/20/20 and went back to cooking outside tire. Ugh.

Tried 10/10/20 and still cooking.

This is going to take some more time. I will post again when I have more time to mess with it.

Well since the 5/5/5 test worked, then at least part of the problem is in LSD, and the other half is in suspension.
This is why, as far as I recall, the top tuners do a rough suspension tune, rough lsd, then fine tune suspension and finally fine tune LSD, in that order.
What I'm confused on, is you said it's not heating up either tire, but it's very loose? Can you be more descriptive about the 'loose' condition, if it doesn't appear to be LSD related, since neither tire is heating up faster than the other under this experiment.
My understanding from your results in this test, imply that the 5/5/5 is masking the suspensions true issues, where previously your other LSD settings were magnifying that issue.

Where to go from here, is usually, just rear downforce, but since that's out of the question, you need to tighten up the suspension or increase rear grip in another way.

My first recommendation would be to lower the front ride height to -5 and leave the rear at 0. This helps weight transfer a little, especially uphill.
Secondly, is ballast required? If it is, then move it. -50 is... all the way to the front right? (Can't remember) Try taking some weight off the front tires and putting it more towards the rear tires to increase grip. Adjust in increments of 25 to start. -25, 0, +25, +50 and see what feels best and then fine tune from there based on feel.
There's a possible shock issue, but I don't understand shocks yet.
I'd watch a replay of yourself and in the third person mode, focus on the rear end of the car in this corkscrew. If you see the back of the car leaning on the LR (outside rear) then try stiffening the rear sway bar to prevent the car from leaning, which could be causing traction issues between the rear tires unevenly. If it isn't leaning enough, soften it up.

If none of these simple things work, then I'd have to say that it's something in the core of the suspension, like shocks, springs, toe and camber.
Again, assuming we can't use a rear wing.

If you want to continue playing with the LSD, for you, I'd recommended starting at 10/5/18, then slowly raising the Accel setting, until the car feels the most comfortable through the corner, without sacrificing traction on the lower speed corners.

Let me know what you tried/worked/didn't work.

 

[Schadenfreude13]

Load up Cape Ring North or Cape Ring Periphery in a ~450 PP FR/MR/RR car on sport soft tires. Run wide open throttle on the uphill loop. The outside drive wheel slowly builds heat and eventually let's go sending you spinning into the guard rail.

I'm sure others have come across this issue before and I'm wondering what suspension or LSD settings will help resolve the problem. The car I'm having trouble with particularly is the Ruf BTR.

I have messed with the LSD but it doesn't seem to make a difference. I have also tried increasing rear camber in hopes that it will give that tire a little more grip. Nothing seems to show progress so I am forced to half-throttle the turn and work the steering wheel to compensate for the twitch oversteer that just won't go away. It just seems like throttle+turning is a bad combo in this car even if you provide smooth steering inputs.

And this is why they have greater camber on the outside wheels of Nascar stock cars... Too bad we can't do camber on individual wheels, and too bad this one small section of a road course or the fix would be easy.

 

[chuyler1]

Sorry I didn't have time to elaborate last night but I wanted to at least log my findings before I had to jump into some other races.

So i think what is happening with the original tune is that the LSD is locking and sending essentially equal power to both wheels. Since the car is turning in this bank, the outside tire needs to cover more ground, but it is locked into traveling the same speed as the inside tire and heating up due to slipage. Changing the LSD to 5/5/5 allows both wheels to travel freely. They both became white on the first lap, but neither turned red like before.

As for the car becoming really loose at 5/5/5...I think removing the LSD from the equation revealed other issues that I need to work out. I will see what I can do about tightening the suspension and getting the car manageable at 5/5/5. Then I will see how much I can increase the LSD without causing the tire burn.

Is ballast required? Technically, no. However for my 450pp racing this car has too much power and adding ballast instead of going crazy with power reduction is often a better approach. Also, pushing the ballast to the front keeps the car from oversteering midcorner and on corner exit. It makes the car a little more manageable in online races where bumping is sure to happen.

 

[esoxhntr]

i think at that power level even 10/20/20 is too high, at least initial. i'd set initial at 7 - 8 or so - accel should be ok at about 20. the other thing i would try is to lower the rear compression dampers and/or springs slightly along with more neg rear camber.

softer damper settings (softer rear compression & softer front extension) would also help with corner exit oversteer - which you currently use ballast for - not the best approach in my mind.

i'll play around with it tonight.

 

[chuyler1]

Yeah, have some fun with it...but keep the PP at 450. You'll definitely have to soften the front if you remove the ballast.