Why is Assetto Corsa so unrealistic? (Straight line grip)

[gold333]

Take any F1 car,

SF70H

MP4/4

Fondmetal Fomet1

MP4/6

Tyrell 021

Ferrari 643

Put the car in 2nd gear in a straight line and floor it.

None of the cars break traction. Like there is a hidden traction control that you can't disable. Or the flywheel weighs 2 tonnes and doesn’t transmit the torque to the tires. Something is wrong.

This is so unrealistic. Has no one noticed this?

We are talking about flooring an 800hp car weighing 500kg in 2nd gear. Has no one driven an actual supercar in real life?

The unrealistic grip is most prominent if the car has no yaw vector. Anything deviating from straight ahead, the grip gets slightly more realistic

 

[BrightCandle]

But it isn't an 800 BHP car in second gear. Either what you do is use the slip of the clutch to keep engine revs high but aren't transitioning much of the energy or you dump the clutch and the engine bogs down at really low revolutions. At 1000 rpm their power output is really poor, sub 100 BHP and the torque is equally awful at 150 Nm. By the time you get into the good powerband you are already moving at quite high speed and there is more traction.

You could setup the car to brake traction in a second gear pull away potentially with adjustments to the gear ratios to get further up the powerband. Given the stated data of the cars, I am not convinced that a floored throttle at 1500 rpm producing 150-200 BHP is enough to break traction for decent slick tires.

 

[Neilski]

Put the car in 2nd gear in a straight line and floor it.

None of the cars break traction.

Yeah, it seems a little surprising at face value but just for fun I calculated the acceleration that 800 BHP would provide for a 500 kg car at a nice round 50 m/s (112 mph, 180 kph) and it's only about 2.4 g, ignoring drivetrain losses. (At that speed, you'd probably be somewhere near the power peak in 2nd, at least in the older cars with fewer gears and peaky engines.)
Then we can take into account the sticky tyres (probably capable of at least 1.6 g on their own), some drivetrain losses and of course the car has some downforce even at that speed. So maybe it's not a total no-brainer that the cars should break traction...

However, it looks like every car you have mentioned is a mod, apart from the SF70H. You can't really blame the game if a bunch of mod cars are unrealistically grippy

And I just tried the SF70H (for some reason it comes with TC, which I had to turn off). It DID break traction in 2nd if I used the KERS button, though not without it. Also, the 2017 cars are a lot heavier (728 kg nominal) than the old ones - at 50 m/s, even 800 BHP at the wheels for a 728 kg car only represents about 1.7 g of accel. (Having said that, you can't reach that speed in 2nd gear on that car cos it has an 8 speed box )

For sure, the modelling won't be perfect (and we have members who can probably comment in much more detail) but it may not be as awful as you feared.

 

[Gevatter]

This is so unrealistic.

Can you provide some data to show that they should break traction in the scenario you describe?

 

[mclarenf1papa]

Take any F1 car,

This is so unrealistic.

Has no one driven an actual supercar in real life?

No one else see the problem here?

 

[Neilski]

No one else see the problem here?

Benefit-of-doubt was being given ;-P

 

[Horatio]

just for fun I calculated the acceleration that 800 BHP would provide for a 500 kg car at a nice round 50 m/s (112 mph, 180 kph) and it's only about 2.4 g, ignoring drivetrain losses. (At that speed, you'd probably be somewhere near the power peak in 2nd, at least in the older cars with fewer gears and peaky engines.)

How to calculate something like that?

 

[Neilski]

How to calculate something like that?

It's just a quick and nasty calc of: 800*746/50/500/9.81
800*746 = power, i.e. 800 BHP converted to W
Power/speed = force; force/mass = accel in m/s; accel/9.81 = accel in g