Double Clutching

[SiVaK]

Hi all

Ive done a search on double clutching and the results ive found arent really telling me what i want to know.

A friend of mine and I both double clutch and heel toe when downshifting into corners under brakes.We do it different ways though, I go into a corner in 3rd start braking with toes, clutch in, move stick into neutral, clutch out, then stab accelerator to match revs while still braking with toes, then clutch in, move stick to 2nd and let clutch out.... My friend of the other hand kinda cheats and goes 3rd starts braking with toe puts clutch in moves stick straightover to 2nd while stabbing the accelerator to match then clutch out...

I need to know which one is correct once and for all from some ppl on these forums because from what i understand of gearboxes(which isnt a whole lot) but i thought that neutral was an actual gear inside the gearbox so that when your at the lgihts and sitting in neutral with the clutch out the flywheel clutch and gearbox are all connected and spinning yet the gearbox isnt putting any power to the wheels its jsut sort of spinning inside the box..right??

So if that is true then logically the way my friend "double clutches"and heel toes would be half doing it i.e. matching the flywheel revs to what the lower gear *will* be yet because he hasnt takin the clutch out in neutral gear he hasent connected the flywheel to the gearbox and matched them fully.

HAHA i hope you guys understand what im talking about..sorry if i cant be more specific, if you need more desciption just ask..

Cheers

[dangerous_daveo]

But... you have syncros... Why waste the time, while your stuffing about chaning gears, I would have just flown past you.

Doing the heal toe blip of the throttle when going down gears is ok, and if your upping it, it would probably help stop compression locks and in general take a bit of stress off things.

Im surprised after doing a search you havent worked that out. In the olden days you needed double clutching, but as people got sick of it, they invented the syncro, therefore eliminating the need for double clutching.

[GunMetalR33]

I do the heal and toe thing but I would'nt bother double clutching....

[Abo Bob]

The short answer is that you are doing it right from the point of view of getting the synchros lined up right and therefore going easier on your gearbox. The way you do it, you could not use the clutch at all if you are any good at it.

I can't see the point in constant rev gear changes without double clutching.

[igor]

For all the people that say to use the syncros - double clutching is not all about sticking the gear in. Neither it is for protecting the gearbox (well maybe a bit). When you double clutch and downshift before a corner the moment you let go of the clutch there is no jerk, everything happens smoothly. This aids stability before the corner and i found that it helps to keep the turbo spooled up.

[Sheriff Wan]

:werd:

It doesn't matter how you do it just so long as you don't get any compression lock-up!!

[eXc]

My take on it is that you are double clutching. You're friend is just doing heal and toe, he is changing gears normally, no double clutch.

That said, I don't see the point in double clutching in modern cars. Maybe they should get dog boxes for cars so we dont even need the clutch.

[relicr31act]

Just a small point but the correct terminology is double de-clutching. And yes there is little point in doing it on a properly functioning modern transmission with synchromesh. Heal and toe is worthwhile to minimise wear on the clutch assembly but mostly to facilitate the use of a "locker" type differential in rear drive vehicles, without compression lockups.

[(B1) MR_fanny]

i did exactly the same as you and did all the reading/driving and found that double de-clutching took that bit longer and was that bit more fidgity that just hell toe'in it. i found hell toe to be the more efficient of the 2 and stuck with that.

[SiVaK]

Thanks for the replies guys.

So i guess its not really worth double DEclutching and heel toeing when your gunning the car hard through corner or even especially when drifting??

Damn i hate being wrong since ive told my friend he was doing it wrong and now his gonna laugh in my face when i tell him he was actually doing it right all along ...=[ ohh well, tis better to learn late then never.

[eXc]

well.....u were double clutching right...he wasn't......so u were right...then again, if u say that u HAVE to double clutch, then u were wrong...

[Yorik]

Unless you have to double clutch, ie. no synchro's, then there is no point in doing it... I frequently double clutch in synchro cars as I drive non synchro's trucks and other vehicles regularly so it is just habit. When I am really going for it, I never double clutch, I find that when I am driving slow, like I do in a truck, that it is more natural for me to double clutch..

If you think you are double clutchin properly and rev matching perfectly, then go and get oyur Truck L's and take a lesson in a non synchro truck you will learn very quickly that you most porbably are not doing it properly, what you are doing is rev matching to the wheels when you release the cluthc with the gears engaged, when in fact double clutching is used to rev match the input shaft of the gearbox to the layshafts for the gear you are selecting, so you are rev mathcing BEFORE you have engaged a gear.. There is a world of difference and in a non synchro it will become truly evident...

[(B1) MR_fanny]

well.....u were double clutching right...he wasn't......so u were right...then again, if u say that u HAVE to double clutch, then u were wrong...

true dat....ur doin the right thing though you might not need to. id say if both of you were takin a corner hard your friend would probably come out first. i always heel toe when i give it some, its just that much smoother.

[Jordan]

Just heal-n-toe into the corners. Its better to be in 2nd gear so you can tickle it around the apex with the throttle and floor it outta there, as opposed to being stuck in 3rd waiting for the apex to pass under brakes THEN chaging down to 2nd and loosing a few seconds trying to catching up to the other guy who was already in the right gear and is now 5 carlengths away and about to change back to 3rd.

[Gts-t]

just to help anyone out. it is to match the gearbox speed to the engine speed or the other way around. people who say there is no need for it must not have mastered the art because its so painful to NOT double clucth down a gear its not funny, unless u drop to such a low speed its pointless.... oh and there is no point doing it changing up gear, pure waste of time.

anyway procedure is...

commin in hot in 4th for eg, ball of foot on the brake, clutch into neutral(sp) clutch out, rev to the amount of rpm 3 would be doing(with the heel of your foot, keep braking too with your ball if ur good) for the speed you will be doing in 3 when u have finished changing.

This can be made easier by revving higher than the rpm needed (its still smooth) rev under the rpm third would need (more than 4th obviously) and you have stuffed up. so uve gone brake, clutch in, nuetral, clutch out, rev, clutch in, select gear in this case third. then hit the gas and your out of there with no damn compression bullshit and when practised is just as fast as not doubling, and theres none of that jerky taxing clutch/gearbox shit going in, hehe.

Used to have a corolla that wouldnt select 3 third unless i revved it in nuetral on the way down from 4th (or up )and gave it the rpm third required for it to slot in. it literly wouldnt go in with the clutch in. had to push against where third is and just rev it till the gearbox and engine matched up then it would slot straight in.

Havent tried the one cluth in the skyzie yet tho dumb idea , just the double.

i know thats made no sense its late and i thought id throw in my 2c worth since i can do this with my eyes shut....

one last note, its pretty satisfying being able to change down at bullshit rpm with nothing but total smoothness and the engine/box/clutch loves you for it, car stays balanced and so on.....

[eXc]

Don't need to double clutch?

But in fast and the furious Vin Diesel says he shoulda been double clutching...during a drag race...in a 10 second car...but the drag takes a minute or more...

How could hollywood be wrong?

[WhiteR33]

Of course they can be.... and don't think they are doing a quarter either....

[MerlinTheHapyPig]

so...

heel toe - matches engine speed with speed of gearbox

double-de-clutch - matches engine speed wiht gearbox, and input&output shafts of gearbox

because its so painful to NOT double clucth down a gear its not funny

i don't see the point of double-de-clutching instead of just normal heel-toe. I can heel-toe at high speeds, and it's smooth-as - if you're getting this problem i'd say your syncros are screwed, or you're not revving it enough.

matching input and output shafts of gearbox, is the job of the syncros.

the only reason i can see to double clutch is to save wear on your syncros.

If you want to see heeltoe being done properly at high speeds, watch "drift bible" or something.

[Gts-t]

so...

heel toe - matches engine speed with speed of gearbox

double-de-clutch - matches engine speed wiht gearbox, and input&output shafts of gearbox

i don't see the point of double-de-clutching instead of just normal heel-toe.  I can heel-toe at high speeds, and it's smooth-as - if you're getting this problem i'd say your syncros are screwed, or you're not revving it enough.

matching input and output shafts of gearbox, is the job of the syncros.

the only reason i can see to double clutch is to save wear on your syncros.

If you want to see heeltoe being done properly at high speeds, watch "drift bible" or something.

If you do not rev it while the the car is in neutral with the clutch out (NOT PUSHED IN) then there is no point the two things above go hand in hand, there is no point of one without the other.

its plain and simple, just rev the car in neutral on downshifts to more rpm than the lower gear would need. its not rocket science

oh and exactly what is this funky "normal" heel and toe you are doing at high speeds, how does that go? are u changing up or down, hehe..... this is gonna be good for a laugh. please describe "normal heel-toe"

[wreckedhead]

hahah by the time you double clutch your car around corners and on the staright, i would have left you by miles. what a waste