Yep. I know, because I drive a manual car IRL. A clutch is useful for a good start. But it can be done too with a strong automatic car with just one pedal.
Like an AMG Mercedes ... you can control the wheelspin with the throttle a bit and get a better start.
It doesn't change the fact, that it seems impossible to get a real advantage by throttle control. I did a few test runs on the drag racing track and all I got was 0,05s one out of ten times ... it should be a visible advantage. At least one car length or so and not just 0,05s on 400m ...
Try it yourself. Use automatic as help, because then you get the exact same gear changes and the only difference is the throttle control. You won't get really better times in all the cars, which you can start full throttle. The formula 1 car does make a difference, because it gets unstable full throttle and has a traction control.
But all the other slick or road cars are nearly best started with full throttle if you don't change the setup.
The one thing that stays in my mind is, that it has something to do with the tyre temperature perhabs. At the start they are always cold. Perhabs full throttle is as good in LFS because tyres get faster on temperature ... have to test that out with telemetry ...
I think this is one of the problems with launching in LFS. It's not what IS trying to be represented, but what ISN'T being represented. Problem is it would require more calculations increasing the minimum requirements for the game. This would be a great opportunity to bring in PPU's but then that would require people upgrading, which couldn't be justified I think, not without more games out that use this, the next problem would be that EVERYONE would have to have the PPU to play with each other as the PPU would change how things occure compaired to someone not runnign a PPU. There is also the option of using a dual card setup, using one card for the video and one for general processing, but then people would need two cards...
The tires are fine and slip angles are accurate. I think there still is a problem though with the way the car uses the traction under braking though, which miht effect accel but to me the accel traction is ok. One thing that cannot be simulated wis the actual gripping of the tires on the road and in LFS it's essentally two smooth objects on each other, this might cause some issues I do not know.
I agree with Tweaker here that the clutch is not accuratly represented at all and would need changing to have any effect on launches. The way it's setup now is that if the computer senses a stall coming it disengages the clutch, which I have never liked.
@BBT Yes if you switch out the motor mounts to solid mounts in the SRT-4 you will significantly reduce wheelhop. Due to the twisting of the engine/driveline like Bal00 said.