this is just a replay from me shifting without clutch
it was to show my dad how realistic this game is, cuz he explained me u could shift without clutch...

comments r welcome
only when it starts i used clutch but that is the only time

hmm, i noticed that you can shift whit out cluch in LFS. But I didn't know that is real . So why you don't need to press cluch? You low the revs and swich then high them and you are in gear, I made it that way... But is this really real

Yes, it is real. But it's even too hard in LFS, because the revs have to match almost perfectly.

I kinda feel like Fox Mulder showing people that it exists , but here is proof for the unbelievers:

http://www.youtube.com/watch?v=g4xyTHsPFfk

If you click the username, you can view more videos where they do clutchless shifting.

Quote from AndroidXP :

Yes, it is real. But it's even too hard in LFS, because the revs have to match almost perfectly.

Depends how you do it in lfs. If you stay in 3rd but move gear lever to 4th then try to change without clutch it is easy. The otherway round going down gears like that is easy too.
Doing it as you would in a real car though not tried it, but from knowing how it is done IRL then lfs should be difficult too (i assume by comments like your's android that it is difficult)

wow it looks easy IRL on that V8 video

That video has me a bit baffled too, do these cars have something additional installed to make the clutchless shifts easier? I mean, aren't you normally supposed to lift of the throttle a little to remove pressure from the transmission? That guy in there stays fully on the loud pedal and just shifts up without moving his feet one bit.

Clutchless shifting in road cars is much harder than race cars, its because road cars have helical gears, where as race gearboxs have strait cut.

helical being quite gears, and strait cut being loud (hense the wining you here on most race cars)

My cousing used to clutchless shift in his beetle, with a loud "CRUNCH" added to it

And the reason for that is...? Does the collar need to be designed sturdier that makes it harder somehow? The reason helical versus straight isn't enough for me, because that alone is no reason at all

Quote from AndroidXP :

That video has me a bit baffled too, do these cars have something additional installed to make the clutchless shifts easier? I mean, aren't you normally supposed to lift of the throttle a little to remove pressure from the transmission? That guy in there stays fully on the loud pedal and just shifts up without moving his feet one bit.

They use really durable transmissions in v8 supercars which allows them to do this. Some people like Greg Murphy even up and downshift w/o clutch, but it seriously wears down the gears quickly. In the enduro races they always use the clutch.
They also don't have synchronizers in the transmissions which makes clutchless shifting "easier".

well, helical gears need to be slowed down in order to sync with with gears, because of the nature of helical gears (the angle) and the distance between the splines, its dificult to change gear while they are moving at speed.

wether as strait cut gears, the distance between the splines is greater, and the chance of the gears syncing at speed is greater.

(Had a lesson on gearboxs last week at collage, its still vague...)

Quote from AndroidXP :

And the reason for that is...? Does the collar need to be designed sturdier that makes it harder somehow? The reason helical versus straight isn't enough for me, because that alone is no reason at all

Straight cut gears can handle higher loads which means more reliability and more power.

Wait wait, what do the splines have to do with that? The gears inside are always connected, so it's completely up to the collar and its dog teeth.

@mikey: Yes, but that doesn't explain why you can shift them up so easily without having to relieve stress on the transmission . Oh well.

Oh , like that. Sorry wasn't reading good enough
But I don't know really. I read something about that the side loads are different, but I didn't really get that explanation. I'll try to find a better answer but I hope someone on the forum will come up with one.

edit:
Closer gear ratios help clutchless shifting too


offtopic:
yay, finally summertime

yes, most gearboxs have the gears already meshed (Constant mesh), but the gears still have to move to engage.

No, the gears don't move to engage, the dog rings and selectors move to link the input shaft to a particualr gear set. Helical or straight cut makes no difference in this, it's down to whether you have dog rings (race boxes) or syncro rings (road boxes).

Can't really compare the V8 Supercars sicne I think they have a special system that you don't have to clutch in or release the throttle to change up from 2nd or so. If you listen closely you can hear the throttle is cut automatically even with the pedal fully down when changing gears.

Quote from tristancliffe :

it's down to whether you have dog rings (race boxes) or syncro rings (road boxes).

whats the difference ?

Syncro rings will tend to make clutchless shifting easier in some respects (as it'll attempt to match the revs automatically), but it'll be slower. Dog rings will either require more precise rev matching by the driver, or just forcing them together and letting the drivetrain/crank twist/wheel slip (lock) etc take the change in rpm, with the associated dog wear.

Thanks for clearing that up

that bit is clear but whats the actual difference in design ?

Quote from tristancliffe :

No, the gears don't move to engage, the dog rings and selectors move to link the input shaft to a particualr gear set. Helical or straight cut makes no difference in this, it's down to whether you have dog rings (race boxes) or syncro rings (road boxes).

i was trying to say that, came out a tad wrong

lol, isnt it about the gears having the same speed as ur rpm or so??
i dunno, its just fun but takes practice

Quote from Shotglass :

that bit is clear but whats the actual difference in design ?

You mean what is the difference between a toothed dog ring and a toothed syncro ring? Well, the syncro is basically a ring with the inside diameter at 45°, which rubs on another 45° bit on the gear drive, and acts to speed up or slow down the input shaft as it is pressed together until the difference is enough for the teeth to engage. The racing dog ring is pretty much the same, but without the cone, so that it can engage quickly...

Not the easiest thing to describe with words, maybe a bit of googling might help. Not sure if there is a wiki article on it, but you never know.

http://auto.howstuffworks.com/transmission3.htm ?