Mustang RTR drift conversion to grip car

  • Thread starter vinz7531
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vinz7531

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France
France
Hello,

I tried for hours to convert my mustang RTR drift car into a grip car... but failed
1) Engine insane torque is hard to control without losing all acceleration capability (longest gears, 30-35 acceleration differential)
2) Oversteer: I tried to make anti rollbar and spring / dampers medium at the front and soft at the rear. but I can only remove oversteer with adding massive understeer.
3) I corrected wheels geometry to Nascar values.
4) I lowered braking differential to avoid locks

Still the car is not good and massively outlassed by S class V8 supercars.

If someone has time and like challenges, I'd be happy to have a look at correct settings :)

thanks
 
I will try tuning this car tomorrow morning. I will let you know how it goes. What class are you looking for? S Class?

If you want to, you can tell me the weight of your car as it is now, and the split weight percentage, and I can give you a good place to start on the Tune.

By turning the Diff settings down, you will only make your cars handling problems worse. Yes, it might give you a little feel of improvement, but after it picks up the RPM's it's going to go completely out of control again. The DIFF setting should only be used as "fine" tuning for a car. It will not fix your rear grip problems,
 
WFO Krypto
I will try tuning this car tomorrow morning. I will let you know how it goes. What class are you looking for? S Class?

If you want to, you can tell me the weight of your car as it is now, and the split weight percentage, and I can give you a good place to start on the Tune.

By turning the Diff settings down, you will only make your cars handling problems worse. Yes, it might give you a little feel of improvement, but after it picks up the RPM's it's going to go completely out of control again. The DIFF setting should only be used as "fine" tuning for a car. It will not fix your rear grip problems,
Click to expand...

Thank you.
The car is R class it will stay in that class (not maxed) as there is very few upgrades possible. RWD
I'm looking to race it against NASCAR or SUPERCAR depending on it's speed.
I'll give you weight and split percentage when I'm home

Thanks for the differential explanation
 
Actually, by turning your Diff down, you can make your car under steer on corner exit and you wont be able to tune it out. You can turn the DIFF up a little to fine tune under steer on exit.
 
WFO Krypto
Actually, by turning your Diff down, you can make your car under steer on corner exit and you wont be able to tune it out. You can turn the DIFF up a little to fine tune under steer on exit.
Click to expand...

Hi,

Weight is 1424 kg

51% front

Power 746 kW (1000 HP) !!!!


I'll try to reset and redo my tune, following your advice


EDIT:
OK, Ithink I've come up with something workable:
performance is around a V8 supercar (except it's faster on straight lines and slower in corners)
I only list what i've changed

Gearbox 3.27
Alignment: camber front -2 rear -1.5
Anti roll bar: front 14.18 rear 8.29
spring: front 168 rear 135
suspensions: spring? front 6.5 rear 4.9 damping front 4.5 rear 3.1
Aerodynamics: front 100 rear 139
Differential: aceleration 64% deceleration 17%

Anyway I'd be happy to test other setups :)
 
Last edited:
Alignment: camber front -2 rear -1.5 (start and adjust from here)
Anti roll bar: front 15.81 rear 15.19
spring: front 624.5lbs rear 600.0lbs
suspensions: Rebound front 9.8 rear 10.6 Bump front 4.9 rear 5.3
 
WFO Krypto
Alignment: camber front -2 rear -1.5 (start and adjust from here)
Anti roll bar: front 15.81 rear 15.19
spring: front 624.5lbs rear 600.0lbs
suspensions: Rebound front 9.8 rear 10.6 Bump front 4.9 rear 5.3
Click to expand...
Hi,
I'm gonna test these settings... Is the car stock interms of upgrades?
Thanks again

Vinz
 
WFO Krypto
These setting are based on the weight and percentage that you gave me.
Click to expand...
Hello,

I tested both settings on Silverstone in a race against V8 supercars.
- my setting: overall correct, but two problems: Loss of rear grip in fast corners, wheelspin when pressing the throttle at corner exit. The car is twitchy.
- Your settings: Good, the car is stable even in fast corners, safer upon acceleration. It just has some understeer at corner exit (but it fits my driving style). It's far better than mine :)

Question: I was told that having softer rear antirollbar, suspensions and spring generate understeer and prevent losing the rear. But in this case it's the opposite. Can anyone explain me this point?

@krypto: Has the tune be created form a tune generator? If yes which one? It's rather good...

Thanks again
 
I have a calculation that I do based on weight and percentage front to rear. I shoot for a target "split" between the front and the rear.

People are going to give you comments like "always run your anti roll bars softer in the rear", or "always run your springs stiffer in the front". That's all a bunch of "he said she said" old wives tails. Every car is different. You can not make a blanket statement like these based on facts. The Forza cars and their handling are based on physics. Physics are constants based on several inputs. Imagine trying to solve several different equations using the same formula. You can't do it. You might get close sometimes, but to get the absolute best out of each mechanical input in your car, you have to tune the car using the inputs that car is giving you.

Just like a lot of people use the aero settings and the tire width to compensate for bad tuning. I very rarely upgrade front tire width. Most of the time I make sure the rear width is at most 1 upgrade bigger than the front tire width. Very few exceptions I have used 2 upgrades wider than the front. I very rarely use a roll cage. A roll cage compensates for a poor tune 90% of the time. There are some cars you just can't fine tune without a roll bar upgrade, but they are very few and far between.
 
Thank you for that answer.
A question just to help me better understant where to start when tuning a car.

If a car is heavier than this mustang, like a 1900 kg (4200 lbs) with still 51% front, what would be the changes?
- stiffer spring to conpensate tfor the weight?
- stiffer anti roll bars?

If a car is still 1400kg (3100 lbs) but has more weight to the rear (mid engine) like 45% front, what would be the changes?
- softer rear spring, harder on front ?
- softer rear anti roll bar, harder on front ?

Suspensions changes more depending if the track is flat (harder) or has bumps (softer) ?

Thank you,

Vinz
 
vinz7531
Thank you for that answer.
A question just to help me better understant where to start when tuning a car.

If a car is heavier than this mustang, like a 1900 kg (4200 lbs) with still 51% front, what would be the changes?
- stiffer spring to conpensate tfor the weight?
- stiffer anti roll bars?

If a car is still 1400kg (3100 lbs) but has more weight to the rear (mid engine) like 45% front, what would be the changes?
- softer rear spring, harder on front ?
- softer rear anti roll bar, harder on front ?

Suspensions changes more depending if the track is flat (harder) or has bumps (softer) ?

Thank you,

Vinz
Click to expand...


If the car is heavier, obviously you have to make everything more stiff.

If your percentage changes, then you have to adjust accordingly to get your desired split. Mid engine cars you are usually trying to get weight transfer to the front to compensate for the high rear percentage.

I find that the cars I like the best are the 50% cars. Easy to tune, easy to drive, and very forgiving.
 
WFO Krypto
If the car is heavier, obviously you have to make everything more stiff.

If your percentage changes, then you have to adjust accordingly to get your desired split. Mid engine cars you are usually trying to get weight transfer to the front to compensate for the high rear percentage.

I find that the cars I like the best are the 50% cars. Easy to tune, easy to drive, and very forgiving.
Click to expand...
Thanks
 
Hi,
Sorry for the double post but I have new information. I just got a phone app called Forza Droid (for FM3).
It allows to get tunes based on a the same criterias as the one Krypto needed.
Here's the setup I got for the Mustang RTR Drift:

in Kg

tyre pressure: front 2 rear 2
camber: front -1.0 rear -0.9
Toe: front 0 rear -0.1
caster: 5.1
anti roll bar: front 20.4 rear 17.6
spring: front 140.7 rear 128.9
rebound: front 7 rear 6.4
bumps: front 5 rear 4.6
brakes: crap values :)
differential: crap values :)

I tested it on silverstone in a race against V8 supercars: the car is less reactive than Krypto's and it has more understeer. But it's more stable.
All in all, I was able to push more with it because I felt more confident not to spin it.
But krypto's car looks like it can do better lap times if you don't make any mistakes.

It's still unstable under braking (rear goes sliding) and I have tests to perform to understand the effect of lower tyre pressure and less pronounced camber.

This app looks like a good starting point to tune a car, or to understand the basics by testing values.

next cat I will test: Ferrari 812 and Kia Stinger... both a pain to drive :)
 
Tire pressure should be 27.5 with race tires. Drive it more than 1 lap. Sometimes the tires need a lap to get up to race temps.
 
WFO Krypto
Tire pressure should be 27.5 with race tires. Drive it more than 1 lap. Sometimes the tires need a lap to get up to race temps.
Click to expand...
I only made 3-4 lap races until now. If needed I'll modify tire pressure...
P.s: the tire pressure I gave were Kg
 

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