#2 Saleen, oversteering no matter how I tune it

Forza Motorsport Legacy Motorsport FM4 Discussion
1

I have big trouble to tune it properly for R2 class, it is always overseer and tires spin when turn no matter how I tune it.

following are my upgrades

  • removed first level restrictor
  • race driveline
  • widest front/rear tires
  • biggest front/rear rim sizes
  • rim style is 5Zigen ZR+520

The upgrades results R2875, weight 1,153kg, front 40%.

Tunings are

  • tire pressure, 2.1 bar both front and rear
  • final drive 3.35
  • camber -0.4 both front and rear
  • front toe 0.1, rear toe -0.1
  • caster 4.0
  • anti roll bars, front 12.3, rear 9.8
  • springs front 72.2kg/mn, rear 62.9kg/mn
  • rebound front 2.9, rear 11.7; bump 1.8 both front/rear
  • aero doesn’t seem to impact, front 172kg, rear 241kg
  • braking front 75%, force 150%
  • differential acceleration 35%, deceleration 20%

I tried to set anti-roll bars or damper to some extreme values but it does not seem to solve the problems completely.

Anybody can see what’s wrong with my settings?

2

Oversteers when? Into the corner, on exit, through the middle, power off, power on? Can you be more descriptive.

3

Yakov Alfa stated my experience as well.

4

lower the front tire pressure and raise the rear pressure. if that does not take enough out try negative toe in the front and positive in the rear. negative toe trys to keep a straight line and positive trys to turn, so while in a corner the front is turning even tighter while the rear is still trying to go straight, the front goes inside and the rear outside, thats oversteer.

5

I was literally just driving that car last night… It threw me off just how much oversteer there is. The really weird part is it’s not just at one point, it’s at every point during a corner. Entry = Oversteer. Mid-Corner = Oversteer. Exit = Previous Overtsteer + Throttle-on oversteer. The car’s just a mess… The best way I can describe it is like driving a FWD when you let off the gas and the rear gets light, except it’s always like that and you can’t just pull the car through the turn with the gas due to it being RWD. I tried a whole bunch of different settings, but I eventually just gave up and embraced the issue. It makes you horribly slow, but at least the car will get around the track…

I’ll try some of your guys’ suggestions and let you know if anything works. It just blows my mind how weird it handles…

EDIT: Alright, I got it to behave a little bit better. I still don’t like how light it gets, but it’s drivable. Keep in mind that tuning really isn’t something I do regularly, so my settings aren’t exactly LB ready… Here’s what I’m running:

R2 875

Upgrades:
-No restrictors (764HP)
-Race driveline
-Racing slicks (stock)
-335mm front tire width
-325mm rear tire width (stock)
-RacingHart C4 rims, 20" rear, 19" front.

Tune:
-Tire pressure: 30.5 front, 29.0 rear
-Gearing: 3.49 final, 2.55 first, 1.85 second, 1.40 third, 1.13 fourth, 0.93 fifth, 0.80 sixth
Camber: -0.5 front, -0.5 rear
Toe: -0.5 front, 0.5 rear
Front caster: 5.0
Anti-roll: 35.80 front, 32.70 rear
Springs: 852.0 front, 880.0 rear
Ride height: 3.4 front, 3.4 rear
Rebound: 9.3 front, 9.1 rear
Bump: 7.5 front, 7.9 rear
Downforce: 451 front, 631 rear
Braking: 50%/no bias, 200% pressure
Differential: 75% front, 75% rear

What seemed to help the most was the toe and differential. Nearly maxing out the suspension helped a little bit too, but it still feels really light. Was running 1:21s around Laguna Seca, but I tend to push cars too hard and end up blistering the tires (I run 220F at nearly all times) and wearing out the car within a few laps… Oh well, I’m only running it for “fun” anyways. Lol

6

Well I had a chance to drive the car and I have to admit that I kind of like it. The first thing I come away with is that the front end of the car has an extreme amount of grip. The car also turns in very fast, which I like. The problem seems to be that a fast turn in can build up so much yaw that it breaks the rear end loose. It actually puts down power very well, all things considered. It’s pretty fast IF you don’t turn in aggressively. My current tuning strategy is to soften up the car while stiffening the anti roll bars to keep responsiveness. …Encouraging results so far. More to follow later.

7

your front tire pressure should be the lowest, not the highest. try lowering the downforce. it’ll reduce tire heat and give you better acceleration. lower the front more than the rear that way when the rear starts sliding outside the front slides outside also keeping the car vertical to the track. you’ll need to hit the apexes and probably slow a bit more in the corners but you’ll get the time back quickly on the straights. just be prepared to brake tap at the top of the hill after the starting line if you start jumping the bend, and wait for the front to settle before getting back on the gas going into the corkscrew so you drive down it not jump down it. your toe is also a bit much, try 3 rather than 5. (i’m also taking it the second front is rear), it’ll bring down the tire heat too.

8

Try moving the brake pressure front and back. I will work on the tune and setup later today. I’ll get back to you.

9

Same here

10

Here is the tune that has given me the best results;
tire F/ 28.0 R/ 27.5
gearing,
Final drive, 2.95
1st 1.88
2nd 1.51
3rd 1.30
4th 1.09
5th 0.98
6th 0.89
camber F/R -0.5 toe F 0.0/ R -0.1 front caster 5.2
Anti-Roll bars F 16.58/ R 16.60
Springs F 796.5 R 805.5
Ride height F/R 3.4
Rebound stiffness F 11.0 R 10.5
Bump stiffness F/R 1.5
Aero F 361 R 505
Braking force balance, 60% to the left (front) pressure 70%
Differential Acceleration 10% Deceleration 15%
I hope this works for you. I don’t know which track you were using it on so the tire pressure is at general point good for use on most tracks.

11

Thanks, I will give a try at a later time.

P.S I bought a tuning setting in marketing it works amazingly, I will see how your tuning working.

12

Interesting approach. Basically you’re using gearing and differential to lower the drive torque. I still think that if you can give grip to the rear of the car it could be very fast. …I’ll see later today :slight_smile:

13

It grips fairly well, I have to say. Just one thing I don’t quite understand m your spring seems way too high comparing with the weight of the car and weight distribution. Is there any particular reason you did so? And I think even the rebound and anti roll bars values are much higher than my normal understanding.

14

the car is a beast on speed tracks properly tuned like lemans.

15

I was doing laps in test drive and tune at the same time. When something was wrong I fixed it by making adjustments and what you see is the end result. To be honest I really don’t like the car especially the way it handles. I have a feeling the car was meant for a more skilled driver than myself.

16

For what it’s worth what I came up with:

Tire Pressure F/29, R/28
Gearing stock (I actually quite like it)

Camber F -1.2, R -.9
Toe F 0, R -.5
Caster 5.0
Anti-Roll Bars F 20.3, R 16
Springs F 576.5, R 710
Ride Height stock
Rebound F 9.5, R 11.2
Bound F 2.0, R 2.5
Aero F 356, R 515
Braking stock
Diff F 58%, R 12%

I hope that helps. Side note, it can be tweaked with front bar and rear aero.

17

Regarding the OP’s tune…
Here’s what I would do just to start. Increase camber in both ends a bit. A bit more negative toe in the rear will alleviate a bit of oversteer. Lowering the caster with higher camber will help reduce scrub (or so I’ve found). Running your front roll bar higher will help higher speed stability, especially mid-corner. Keep the rear bar the same. Your spring rates could be a bit stiffer, particularly in the rear. Rear biased spring rates aren’t a bad thing when dealing with oversteer as you can counter it in other ways… One thing I know that is exacerbating the oversteer is the rebound setting you have. It’s extremely rear biased! Try something more neutral and front biased (7.0/5.5 for example). This car has a significant amount of downforce, so you can run your bump stiffness a bit higher, again setting it biased more towards the front. Your brake balance at 75% is killing the car, honestly… I wouldn’t ever go past 52% if you’re setting it to the front. It doesn’t make too much of a difference past that point, and the car just feels awkward. I normally go with 45%, but that’s to get a car turned in more under braking, so 50% give or take a few clicks will do. You can also lower your acceleration and raise your deceleration differentials to tame the car a bit more. If all else fails, this may just be one of those cars that has improperly balanced downforce, so you might just have to take a bit of it off the front… Not ideal, but it’s better to make the car driveable. Sorry if that was too detailed, but I didn’t want to miss anything! It’s not a spectacular car though, so don’t get discouraged if you can’t get it right. There are much faster and better feeling race spec cars in R2.

18

Good news! The majority of the oversteer is gone! It’ll still get a bit unhappy if you try to run it carelessly, but it’s considerably more driveable now. The tune is the same one from my first post, except with the following changes made:

Tire pressure: 29.5 front (all tires run around 34.2PSI under race temps now)
Toe: -0.2 front, 0.4 rear
Rebound: 7.0 front, 5.5 rear
Bump: 8.0 front, 7.5 rear
Downforce: 340 front, 550 rear

I believe the lower front aero is what helped the most. There’s a very fine line between grip and sliding with this car, but I enjoy driving challenging and oversteering cars so I love that “negative.” Still runs low 1:22s, high 1:21s on Laguna Seca, so there’s a very minimal difference in lap times between the slippery and grippy tunes oddly enough…

rdo3, aren’t you just supposed to set your cold tire temps so that under race temperature the tires run somewhere in the mid 34s? I was always told to try to match warm PSI, and the rears run hotter than the fronts so I pretty much have to run lower rear PSI, correct? I just tune my cars to a point where they’re decent feeling; I normally don’t bother with the “rules of tuning” so to speak, so this threw me off…

19

It’s interesting how different tunes approach the same numbers from different ways

20

The “rule of thumb” for tire pressure has always been 32 psi at temp. Higher pressures can be more responsive, but less grippy due to the lower temp. I’ve found that anything in the range of 32-34 is usually fine, as long as the rest of your set up is balanced correctly.