Why do stock tuning setups handle so poorly?

Forza Motorsport Forza Motorsport (2023) Discussion
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202

I like to start with these settings then work my way through adjustments after.

I was told by ESV Green that mid-corner understeer is the result of front body roll, ever since I prioritized stiffening the front of the car, my mid-corner understeer has vanished.

Start with these values (Has worked for every car so far, from E to X)

Alignment
-1.0 Camber front and rear
0.1 Toe
7.0 Caster Angle

Anti-roll Bars
40.0 Front
1.0 Rear

Suspension geometry
9.8 Roll Offset Front and Rear

Now with those settings applied we can work out any other issues to get the car handling optimally

Understeering On Acceleration
-Increase Acceleration Differential
-Increase Anti-Squat
-Reduce Rear Downforce

Oversteering On Acceleration
-Reduce Acceleration Differential
-Reduce Anti-Squat
-Increase Rear Downforce
-Reduce Tire Pressure (if issue applies to slow corners)
-Increase Tire Pressure (if issue applies to fast corners)

Understeering Mid-Corner
-Increase Front Downforce
-Reduce Deceleration Differential
-Increase Acceleration Differential

Oversteering Mid-Corner
-Reduce Front Downforce (advise against this)
-Increase Deceleration Differential
-Reduce Acceleration Differential
-Reduce Rear Roll Offset

Understeering Under Braking
-Reduce Anti-Dive
-Adjust Brake balance to the rear

Oversteering Under Braking
-Increase Anti-Dive
-Adjust Brake balance to the front

Springs and Dampers
Springs and dampers are very situational per car, but generally you’ll want to run lower front rebound stiffness to help with bumps/curbs and harsh left/right turn transitioning.

Springs are usually fine around the mid-way point or lower in my experience, with the front being slightly softer.

Start with stiffness values between 7-9 with the front being slightly softer.

For rebound, run values between 7-10 with the fronts being softer by 1-2 and if you experience lack of grip on downhill/uphill, consider adjusting the front to be stiffer.

Tire Pressure (PSI)
Tire Pressure is very situational, and also depends on the car. Some cars can run 20-24 while others must run 28-32 for optimal grip.

Front tire pressure has a sweet spot for each car, and going outside that range will just result in understeer at all speeds.

Try turning the rear tire pressure down until you start to lose grip on fast corners.

Low Rear tire pressure is good for tight/slow corners, increasing grip for acceleration but causes sliding on fast corners, adjust accordingly

Forza physics issues
Not all cars seem to run on the same physics, and so some cars in the same category can run tire pressure MUCH lower than they should.

This also applies to downforce, there are some high class cars that can run maximum front and minimum rear downforce and stuff no handling issues like oversteer. (Most cars below R class will handle just fine with Max Front-Min Rear)

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203

Hornet laid out tuning options well so you can mess with those. I just want to know are you basing things off feel, or basing things off time. Sometimes youre not going to get a fast car that feels great, conversely you can have a car that feels great but isnt fast enough.

Cars can also have certain traits that cant really be tuned out. You mentioned body roll, at a certain point youre limited to how stiff you can actually make things to combat the roll. Sometimes the best you can achieve is finding a way to not so much combat it, but drive it how it needs to be driven. Basically play to its strengths rather than focusing on its weaknesses.

204

Yea I’ve tried those settings he suggested before even asking here. Just the physics? Idk, the feeling in the wheel makes it feel like your driving a tractor trailer or a boat. I had that same issue w the gto but some ballast actually fixed that :ok_hand:. Usually don’t have too much trouble tuning a car, just this one had me stumped.

I’ll tinker around w it some more today, but I think this car is just not balanced well from day one. Idk we’ll see what I can come up with today.

Update:
I guess I was just having an off day yesterday :person_shrugging: hit reset and started over and already getting a decent time.

Thanks to all for chiming in.

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205

Can you post screenshots of your current build? Upgrades and tuning numbers

Or at least post all current parts and numbers

What wheel are you using?

I’m really particular about how tunes feel on a wheel, would be happy to look into it

206

I feel like the issue is feeling the weight transfer when the car slides it produces a heavy ffb feeling in the wheel causing you to spin out.

800pi limit/ 788pi build
Current spa time was 2:29 sloppy driving
Medium race tires
G923
No assistance
—-

Ignit- race

Exhaust- race

Air Filter - race

Supercharger - stock

Inter cooler - race

Cam- race

Valves- race

Displacement- race

Flywheel- stock

Oil and cool- stock

Brakes- race

Springs and damp- race

RollB- race

Weight reduction- sport

Roll cage- race

Ballast- light

Tires- race

Tire width- widest front and rear

Clutch - race

Trans- race

Diff- race

Rear bumper- race

Front bumper- race

—-

Tire p. 34/34

—-

Gear 3.81 final

2.43

1.90

1.54

1.26

1.12

1.00

—-

Camber- 2.0/1.2

Toe- -0.1front/0.1 rear

Caster- 5.9

—-

Roll bar-

40.00

1.00

—-

Springs

774.7

790.5

Ride

5.0/6.0

—-

Bump

4.4/4.4

7.1/7.2

—-

Roll

8.7/9.8

26.0

-18.5

—-

Downforce

141 max

Rear 193

—-

Brakes
50/100 was too squirley braking hard
51-53/81 felt better

—-

Diff

74/26

—-

Ffb wheel tuning

always stays at 100%/100%

This is today’s setup after starting over from scratch, and it feels better but still not where I want it to be satisfied. Like you I try to find that good feeling setup and meticulous about it.

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207

I’ll try it out later and see what I can do :call_me_hand:

Are you intentionally keeping it at a PI of 788?

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208

Yea getting it closer to 800 involves adding the supercharger and it’s really wicked to drive.

So far this ballast and weight reduction combo felt better than yesterday’s setup.

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210

:rofl: idk what fomo even means. That’s alright. Since that reset to default and started over it definitely helped was only getting 2:35 yesterday at spa and today 2:29. Little more tweaking it’ll be fine I guess. Thanks anyways

212

It’s hard to feel the changes on a wheel, as there doesn’t seem to be much feedback for slipping tires.

I’d tune the car myself but I don’t have it, I don’t think.

213

I think I had too much negative anti squat I cut it in half on this new setup today. Like I said earlier it was way faster than before. It’s fine for the time being. Thanks for the useful info earlier. Our tunes arnt so different.

214

I’ve seen a good bit about ARBs going 40/40 or 40/1, but haven’t had much luck with this. I think your approach on these may be a bit too heavy handed. What I’ll do is take the stock settings and give them another 10pts or so then set the rear a lil stiffer. Keep the balance of them about the same ( they’re not too far off, just not stiff enough overall ) but push them both as close to 40 as they can go. Then I’ll stiffen the rear until I start losing traction back there 'n back off a tick or 2 when I start to.

So like this M2 I’m tinkering with rn I have them set to 35.27/29.21 from 25.27/19.11. My go stiffer yet, but we’ll see. Feels pretty solid where it’s at.

215

Hey so I replied prematurely and apparently had this car all along. Thought it was under Ford instead of Saleen.

Been using it in the daily race series and it’s absolutely crushing the balanced tracks.

Finished tuning it so here’s my build if you want to try it. I like driving it as much as the E92 M3, if not more in some cases.

V6 swap
Centrifugal supercharger

Race centri
Race brakes
Race springs
Race ARBs
Race weight
Full cage

Sport tires
Max width F/R

Wheels L-Q Raptor

Race trans
Sport driveshaft
Race diff

Race aero - all

Tune
29.5
29.0

6.10 FD
1.91
1.40
1.11
0.91
0.76
0.65

-1.8
-1.2
0.0
0.0
6.0

32.0
40.0

570
533
4.9
6.0

3.1
2.8
10.2
9.7

+3.9
+5.1
+31.6
-10.9

141
148

46%

62%
18%

If on wheel with default 900° and ~8Nm
90%
90%

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216

That’s if you want an A700 tune

I’ll try your build out and see what’s up

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217

I took your build and numbers around spa like you mentioned

I didn’t change any of your parts and tried to avoid doing big changes that would make it feel weird to use, since a lot of that’s so subjective

If this isn’t intended on being a lobby car, then you could try this tune out and see if it’s a little more friendly

Main things I found on the default tune at spa was that it was a little too bumpy (reduced spring rates) and despite having a 50/50 weight balance, it had very little rear stability under braking and exit, so I adjusted springs dampers and dive/squat to counter. Had to add back mid corner rotation using ARBs and brake bias. I know you mentioned you prefer 50/50 or 51-53, but with the suspension and antisquat bias adding stability, it’s more stable now at 48% than it was prior and you’re making more use of the rear tires under braking and still getting at least a little trail rotation

32.0
32.0

3.81
2.43
1.90
1.55
1.29
1.12
0.98

-1.8
-1.2
0.0
0.0
6.0

36.0
40.0

698
645
5.0
6.0

4.1
3.6
9.8
9.2

8.3
9.8
36.4
-22.0

141
211

48%

70%
22%

Got it in 23s while testing but it’s probably solid for consistent high 22s

But if you’re going for something competitive, I would rethink the parts situation

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218

The problem here is the way pneumatic trail works. I heavily rely on mechanical trail, as that tends to give a lot of feedback if the rear steering it, which gives you enough feeling of the rear tires slipping. Pneumatic should be the tire slip setting, but it turns the FFB off entirely once the game determines give give past peak grip. There is no progression in the drop off and it does it too soon.

Having a bit of pneumatic can be useful for telling when the car is understeering, because the car loses some ffb and you still have mechanical trail feeding you information on the rear of the car. Too much pneumatic though, and it turns off ffb when the rears loose grip too, leaving you clueless to what the car is doing. And then of course, the ffb snaps back on as well, meaming if you are the edge of grip, the ffb can start turning off and on in a binary fashion leaving you confused entirely to what the car is doing.

I run a 3 to 1 ratio of mechanical to pneumatic. K1Z Batdca, the fastest wheel player I’m aware of and also one of the fastest in the game period, runs a 4 to 1 ratio.

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219

This one’s interesting and/or disappointing. No matter how much pressure is in these tires on this Lambo SC63, the middle section of the tires have a lower temperature when sitting still. I cannot get the middle to warm up as they should in this telemetry. If the alignment is perfect, which it is here as both the inside and outside edges have the same temperature when sitting still, the middle is still about 2 degrees cooler as the car sits. I have the pressure maxed out right now and this makes no sense. So no matter what, you cannot get an accurate reading on the tire temperature. With this much air in these tires, there should be a bulge in the middle and the middle should have a higher temperature than the outside edges.

Excellent work T10. :unamused:

It isn’t until I start moving again that they show higher temperature. Telemetry needs some work.

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220

From my testing around tunning, I went to conclusions that even if middle tp shows rly low values, it’s better to ignore it and just focus on overall car handling (too high pressure will make car lose grip too often, too low u will have this feeling of understeer), or even easier, just calculate to based on car weight and weight bias.

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221

To find the proper pressure: Front and rear Camber and toe at 0.0 degrees, Straight track, now increase or reduce Tyre pressure. Accelerate hard brake hard without locking and make the tires warm up.
If the car is stock, put the kit required to change those setting, once found remove the kit.

222

what is your calculation for this?

223

still working on it and i use metric units :slight_smile: Forza Calc V1.7.xlsx - Google Sheets

But basicaly its this
front tp= 1.8 bar * (1-(1-car weight [kg] * front bias in %/500[kg])/2)
rear tp= 1.8 bar * (1-(1-car weight [kg] * rear bias in %/500[kg])/2)

And with this tp, calc camber:
front camber = -(front tp [bar]*200/front tyre width)
rear camber = -(rear tp [bar]*200/rear tyre width)
Caster always 7

Tho camber might change if u use different suspension setup that what i use.

Also this TP setup is optimalized for warm tyres, so on 1st lap u can feel that TP is bit too low

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