The online racing simulator
Can you launch your LFS car...
(18 posts, started )
Can you launch your LFS car...
... in a civil manner, as if you drove your mom in law to the hairdresser?

I've had this sim for years but only tried this recently (with the XR GT), and I get moving, but the rpm drop instantly and it probably wouldn't be a smooth ride at all. Big grin

"Your hubby drives like a bully, honey."

Will try some of the other cars now. Maybe even without throttle?
I tried and I think it's harder than in real life, still not sure if because I can't feel the G-forces or because something is not quite right in how the cars react.
With the correct actuation of the manual axis clutch, it is possible to have a very smooth launch. I agree, it's not easy at all Smile
Quote from AnnieC :I tried and I think it's harder than in real life, still not sure if because I can't feel the G-forces or because something is not quite right in how the cars react.

I tried it some more, and I think it's both. In the real world, with a clutch held at a fixed, slipping position, and fixed rpm, the car would gradually pick up speed, which isn't the case in LFS. Not a biggie though, as we hardly ever do this type of driving in LFS. Probably even the cruise-folks regularly dump the clutch to get going... or drive auto.
Well, the bite point of clutch is known to be very small in lfs. One has to be very precise, so 8bit (logitech) pedals will not cut it. With 10bits like the ones from thrustmaster, it's a little bit easier, but still quite challenging.

We did mention this to Scawen, but for bikes. I wouldn't worry about it too much before a new tire physics is released. Then we can go nuts with all kinds of requests Smile
Always drop the clutch bro
Quote from rane_nbg :Well, the bite point of clutch is known to be very small in lfs. One has to be very precise, so 8bit (logitech) pedals will not cut it. With 10bits like the ones from thrustmaster, it's a little bit easier, but still quite challenging.

That makes a difference? Very interesting. I once played around with DX-tweak, mainly for the brakes, though. Maybe one could kind of stretch the area of the bite point that way, but it's probably not worth the hassle.


Quote from MousemanLV :Always drop the clutch bro

Of course. Why should you do it differently than in real life, right? The same with flat shifting. Big grin
Quote from Bandit77 :Maybe one could kind of stretch the area of the bite point that way, but it's probably not worth the hassle.

Yes, that would be doable, it's a good idea. You can play around and make the curve such that it's almost flat at the top, with a very small angle between horizontal line and then a bigger angle down to 0 input. The break point (center) could be somewhat before the actual central value of input. If you are very keen on doing a real life smooth start, some trial and error is required untill you nail the curve.

Note that axis clutch in lfs is saturated completely (fully open clutch) for about 70% of axis input, so take that into consideration when playing with DXtweak axis calibration.
Most of games, LFS included, have wrong engine/throttle model.
In most games, throttle pedal just scales torque curve which is far from realistic. Thats why u don't have enouch torque at low throttle input to launch the car and it's harder compared to reality.
Same for sliding a car. Manipulating throttle to maintain/control the slide is different.

LFS:



Edit: U can even check that by manipulating intake restrictor - it's just lineary scales torque curve.


How it should look like more or less:



As u can see there's a lot less torque drop at low rpm and a lot more torque drop at high rpm.


List of games that have done this in correct way:
BeamNG
Automobilista 1
Automobilista 2
rFactor 2


For now the only way to make this better in LFS is changing throttle sensitivity curve from linear to regressive in ur hardware setting. That will make it more sensitive on beginning. Closer to what u feel in real car.
Quote from versiu :Most of games, LFS included, have wrong engine/throttle model.
In most games, throttle pedal just scales torque curve which is far from realistic. Thats why u don't have enouch torque at low throttle input to launch the car and it's harder compared to reality.
Same for sliding a car. Manipulating throttle to maintain/control the slide is different.

LFS:



Edit: U can even check that by manipulating intake restrictor - it's just lineary scales torque curve.


How it should look like more or less:



As u can see there's a lot less torque drop at low rpm and a lot more torque drop at high rpm.


List of games that have done this in correct way:
BeamNG
Automobilista 1
Automobilista 2
rFactor 2


For now the only way to make this better in LFS is changing throttle sensitivity curve from linear to regressive in ur hardware setting. That will make it more sensitive on beginning. Closer to what u feel in real car.

Would've been nice if you put the source for this Smile

https://www.youtube.com/watch?v=0gW-cbSX3Uc
Quote from Sobis :Would've been nice if you put the source for this Smile

https://www.youtube.com/watch?v=0gW-cbSX3Uc

"This" was well known before he made video about that but yes, I made screenshot of his spreadsheet. Second screenshoot u can find on google like he did.

In the meantime u forgot to recommend his channel as the best sim racing content Cool


BTW maybe it's good topic to improvement suggestions?
Quote from versiu :...

Interesting stuff. Makes sense.

As a side note, the graphs of the two real engines are probably from engines with gas-by-wire, where the computer just gives you an optimized response, until you floor it, where it just gives you what the engine has got, which isn't a smooth curve. First one probably NA, second one turbo.
Quote from Bandit77 :Interesting stuff. Makes sense.

As a side note, the graphs of the two real engines are probably from engines with gas-by-wire

I don't think that changes anything. It represents the real feel of engine reaction to throttle input very well. Just watch this video because my english skill isn't good enough to explain this well:

Do real race cars purposely use clutches with more narrow bite points? Maybe for faster gear changes?
I have very briefly driven two "race cars", prepared for slalom by friends of a friend. (cars purely for track usage, with rollcages and all that)
One was a Ford Kadett C and the other a BMW. We all had some difficulty when slowly rolling to the start line. Very bumpy or even stalling.
Yes, that's exactly why the clutch bite point in real sports cars is shorter. It's a tradeoff between being able to go through gears as fast as possible and a good start from a stand still. In a race, you use cluth to start only a few times, while gear shifts are in hundreds - thousands of times, so this is how it's optimized. Definately a very different use case compared to a normal road car driving.
3 years ago I finally decided to get a driving licence and bought a wheel with 3 pedals to train in LFS. (Used mouse buttons as shift up & down, to imitate the need to reach the shift lever.)

Learning the real car went very smoothly, except for exactly this thing: I revved up very much to avoid stalling the engine.

The instructor yelled at me: "NOT THAT MUCH!!!" a few times the first day. Had to get used to not rev up.

I was really surprised that cars can move without throttle in the 1st gear.

After several days at driving school, I guess, my brain learned two separate patterns of behavior.
In a normal car, this kind of smooth start is a real art. The more you drive the smoother you get. Once you start paying for your own fuel, then you also start to learn all possible ways of gentle driving and fuel saving.
Quote from rane_nbg :In a normal car, this kind of smooth start is a real art.

With my new car, that I bought about a year ago, it took me a while to find that coordination again, where you launch reasonably quick but with the lowest revs and the least clutch slippage possible, followed by the earliest possible super-smooth shift into 2nd. Big grin

But once in a blue moon I still spur them horses and chase them thru the bends. However, maximum-depreciation-starts, as I like to call them, have become very, very rare.

Quote : Once you start paying for your own fuel, then you also start to learn all possible ways of gentle driving and fuel saving.

True, and also to avoid general wear.

Smooth is king, and it can still be quick.

Can you launch your LFS car...
(18 posts, started )
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