wouldnt it be better to startup on a race the way u startup in GTR2?
In LFS, If your REVs are low it will just drop them to zero when the green light is on, and u have to unpress and press again the gas pedal in order to roll.
In the other hand, it will allow u to accellarate only if ur gas pedal is fully pressed, which will propably cause ur wheels to spin, and lose precious time.
what do u ppl think?

I don't quite understand? I never have to release the throttle and go on again to start? Though, if you want a smooth start at medium to high revs you probably need a clutch pedal.

Erm, when accelarating at the lights, when green goes my revs dont drop, nobody's revs drop I dont think, al lthe races with BF1 I had to keep it at a certain level (8000rpm) I think to stop spinning off and to get a good start. Maybe its something with your settings.

mine will just drop to 0 and then i have to release, and press again the gas pedal
(im not using a clutch though)

What kind of controls are you using, and what revs do you try to start at?
(E: apparently wheel?)

There must be something wrong with your controller settings, unless you might need to re-download LFS, I don't know why you have to re-throttle when the light goes green, I have never had that problem before, what wheel are you using?

im using a DFP and for example a car has 10.000 max revs, if im REVing at 5.000, when the light goes green it just drops to 0 and it wont roll

Well, that's different from car to car, but lets see. On a car with 10000 redline, I'd rev to about 7000. Note that while doing so, there is practically NO load on the engine so you only need very little throttle to do this, so when the clutch gets dumped on green light, you have to compensate with much more throttle to stay at these RPM.

If it wasn't for LFS' autoclutch, your current method of starting wouldn't only bog down the engine but stall it. In the end your only choice is to either spin the tyres a little (optimal grip is at 5-8% spin) or you get a wheel that has a clutch pedal.

The only exception is turbo powered cars. In these cars you should immediately give 100% throttle as soon as you can, so the turbo generates boost. This is for example the only way to start the XRR/FXR without losing 10 places on green light.

ok, when using a clutch pedal, what should I actually do to get better starts? usually I just tap it a bit when it bogs down, what SHOULD I be doing?

Slipping the clutch just enough that neither the engine bogs down, nor the tyres start heavy spinning. But because of a complete lack of seat in the pants and clutch bite feel that's extremely hard to accomplish.

Leaving "how it should be" aside, the most risk free way of launching is with spinning tyres. Preventing a burnout is far less important than preventing a bog-down. Actually if you try to do a perfect start by feathering clutch and throttle you probably lose more time than you can make up with more grip. It doesn't exactly help that LFS tyres produce the same longitudinal grip at any slip ratio, besides the ~5-8% range where it has a bit more. I think that's a shortcoming, and combined with the automatic clutch drop at green light it makes the starts a very mundane and uneventful thing.

Have you checked that your pedals are set as "separate" instead of "combined"?

Okay - sorry for being somewhat OT - I just want to point out why feathering is useless, so I dug out an old longitudinal grip vs. slip graph and coloured it a bit. What you can see here is the slip ratio on the X axis, versus the grip (measured in G) on the Y axis. That means the farther we go right, the faster the tyre is rotating compared to the ground speed.

Looking at the colours, we see the blue line, which is where we are most of the time in most situations. On launching, the left blue line is obviously worse than the right one, because it means we use less grip than available, so you can see that as the bog-down line, while the right one is the burnout line. Then we have the green line, which is the start of the little extra grip bump we have, while the red line marks the falloff.

Seeing from that curve, we have more grip at a range from about 0.06 to 0.15 slip ratio. At this point I have to confess, that I'm not quite sure what exactly that ratio is, but I think 0.06 means that the tyre is rotating at a 6% faster speed than the ground below it.
So overall we have a slip range of 9% in which we have more grip. But unfortunately, this isn't quite the case in practice. Because of the falloff nature of the red zone, there will only be very little time spent in that zone, because once we're in red zone it's a quick train ride to blue-land, so we actually have to remove that from our useable range. This leaves us with the puny range of ~2% slip (green zone), in which we actually have reliably more grip than usual.

Now, when you're feathering around, this is very likely going to happen: First you start off in the left blue zone, not giving enough throttle to actually use all grip, wasting time. Then you realize this and apply more throttle, bumping you to green for a split second, then into red and quickly to the right blue zone. You hear tyre spin noises, and back off a little. The grip approaches red, then snaps back into green zone, but because your throttle is not high enough anymore to hold it there it quickly dwindles down into the left blue one, wasting time. Now you apply a bit more throttle and... repeat ad infinitum (= till you reach 2nd gear). All the split seconds you spend in green and red are nice, but far too short to compensate for the loss in left blue zone. Overall it's better to stay in the not-so-optimal but absolutely reliable burnout zone than spending even a split second in the bog-down or not-using-all-grip one.

Personally I think I've only managed a perfect start once after countless tries in the BF1 on a test-layout. I immediately noticed it because the tyres were nicely chirping along, directly on the border between tyre squeal and scream. I couldn't yet reproduce it and I think it was pure a**luck. The benefit from that start? About 0.03 seconds till I reached the finish line (a few metres down the road). Not very impressive, compared to the difference a good start can make in real life.

@AndroidXP

It is actually more complex than that. In LFS the turbo cars need high revs to get the boost high enough for a good start. Best example of this is the FXR. Enough revs and boost and goes like stink from the start. Not enough revs and boost and the UF1s behind you honk you constantly for slowing them down. Or the XRR: not enough boost and it just dies. Enough boost and you don't see where you are going anymore because of the tire smoke

I think the FO8 is the best car in which a good start can give you major benefit. It has enough power to spin the wheels if your not delicate with the loud pedal. It has also enough grip to handle that power with correct inputs . Still, some wheelspin is needed to get the car moving...