Double Clutching......

[RSTDL]

Who knows what double clutching is ? The correct method od double clutching is as below and not the misconception of firing your foot onto the clutch once a gear ahs been engaged whilst still accelerating to get the infamous extra revs! BTW (Vin Diesel in the fast and Furious says "granny shifting, not double clutching like you should..."). .

First: Dont watch the fast and the furious and think it has anything to do with cars. Anything they say about cars in that movie should be assumed faulty until proven correct.

Now, double clutching is done for downshifts only. You NEVER double clutch when you upshift. It makes no sense.

Proper double clutch procedure (downshifting!):

Push clutch in.
Move shifter to neutral.
Release clutch.
Rev engine to a slightly higher rpm than what the engine will be in the lower gear.
Push clutch back in
Move shifter to lower gear.
Release clutch.

So what does it do? It revs the tranny input shaft to the rpm where it will be in the lower gear. That means that when you attempt to move the shifter to the lower gear everything is already spinning at the proper rpm. Done right this pretty much eliminates wear on the synchronizers.

Yes, this was mandatory on old trannies that were not synchronized. It is still useful for downshifting multiple gears. For instance, I will often coast down in high gear to maybe 1200-1400 rpm. Then I need to accelerate and want 2nd gear. A quick double clutch will make 2nd just fall in place with no effort on the shifter lever.

I find it even more useful going into 1st gear while rolling. In many cars it is very difficult to get 1st gear while rolling. A double clutch will make the most stubborn tranny go into 1st.

Here endith the lesson.................works a treat by the way through the forest stages............

 

[lee-2246]

yeh thats what i thought dobble cluchin was but if u over rev cant u weld ur clutch together? which is not good + if it wount go into gear dont that mean ur going 2 fast 4 that gear?

 

[Tom]

if you really want to reduce wear you can by-pass the clutch totally

by matching the revs with the shifts i dont really know how to do it, ive done it by mistake in my mini

(this requires incredible skill do not attempt at high/revs/speed)

 

[Turkish]

Talkin of fast and furious any idea why a peice of the floorpan falls off the green eclipse when paul walker supposedly cooks the piston rings? firstly i cant imagine there is a bolted on panel there secondly it wouldn.t fall out just cuz the engine is on its way out, plus there is the whole if the piston rings were gone then you wouldnt get compression and the car wouldnt run or you would at least have oil burning up and getting sent straight down the exhaust the list of other things that are wrong through the whole film is massive but its a film so who cares they always get it wrong it was cool anyway

 

[TB1]

Lee, why is double clutching going to weld your clutch together????

All you are doing is going from a higher gear into neutral, reving the engine so that the gears are running the same speed then downing, you have only used the clutch to go to neutral so its not like your putting any strain on it and then revving doesnt harm it, then your downing into a lower gear which is what the clutch is designed for

It causes no harm to your gearbox or engine but its not necessary with modern gearboxes as stated above although if you are having problems with a dodgy gearbox then it may help assist you go into gear but id get the gearbox sorted soonest!



Tony

 

[nev16v]

its not that hard to drive around without the clutch, i have none it in a couple of cars when my clutch cable has snapped. just gotta listen to the engine. cant imagine it does much good.

 

[Tom]

Quote: Originally posted by 172loony on 22 November 2002

Talkin of fast and furious any idea why a peice of the floorpan falls off the green eclipse when paul walker supposedly cooks the piston rings? firstly i cant imagine there is a bolted on panel there secondly it wouldn.t fall out just cuz the engine is on its way out, plus there is the whole if the piston rings were gone then you wouldnt get compression and the car wouldnt run or you would at least have oil burning up and getting sent straight down the exhaust the list of other things that are wrong through the whole film is massive but its a film so who cares they always get it wrong it was cool anyway



the thing is full of mistakes

like the cgi bit when he floors the mazda rX7 apparently that rx7 has pistons and and a crankshaft!! lol!!

and when the bird races the guy a race wars. she must have repaced the race seats for standard ones while the camera was on the bloke!!! good girl!!

 

[Ben H]

I use double-declutching on downshifts when I want to keep my driving really smooth (like when my girlfriend is in the car). I find that my car/my normal gear shifting style makes for slightly jerly downshifts as the clutch mates and pushes the revs up itself. If the revs are already higher, then this process is much smoother.

 

[Jeff XSi]

My experience of changing gear without using the clutch has had mixed results After asking a SENIOR observer at the IAM if it was possible and him laughing at me and telling me it wasnt possible on a standard manual car, I decided to try it for myself...



3rd into 4th at 4K revs without the clutch - SWEET AS A NUT . 4th in to 5th at 3.5 K revs - GRINDDDDDDINGG COGS !!! DOH!!! 4th to 3rd downchange - perfect...



I guess I was lucky Funny thing though, the IAM instructor said it WASNt possible unless I had a sequential box - fuppin muppet

"The correct method od double clutching is as below and not the misconception of firing your foot onto the clutch once a gear ahs been engaged whilst still accelerating to get the infamous extra revs! "



heehee thats spinning the clutch

 

[Turkish]

yeah where did vin put his wankel (thats rotory dont be so childish!) for that shot ? answers on a postcard

 

[Tom]

i think it was aimed at people that dont know about cars

or its too hard to animate a rotary engine

 

[Turkish]

surely the people who will want to see a film with modded cars are like us an own or at least have an interest in modded cars, they should have thought about it a bit more really

 

[RSTDL]

If you want to bypass ur clutch altogether fit a six speed sequential gearbox changing from 1st to 2nd to 3rd to 4th to 5th to 6th all at 8000RPM - wham bam thankyou mam................

 

[Turkish]

full throttle shift fcukin lovely. them jammy rally boys get all the decent kit!

 

[Jeff XSi]

yeah but a manual gearbox will do it just as well if you change gear at correct revs and speed



u from n.ireland cupsize?

 

[lee-2246]

TB1- i ment goin up a gear coz sum ppl do it 2 go up an if u rev it to high u cna do sum damage i think

 

[Jeff XSi]

at the end of the day its only really necessary if your syncromesh is worn - or in my case when selecting reverse

 

[cyue005]

woul ddouble clutchin be same idea as Heel and toe method? thats for matchin the revs when goin down the gears?

 

[Jeff XSi]

not really ... heeling and toeing is for keeping a foot free for clutching whilst your toe accelerates and ur heel brakes The shift would just be straight up or down a gear without resting in neutral

 

[RSTDL]

Yeah Jeff Im from N. Ireland - are you?

 

[Jeff XSi]

yep Londonderry mate

 

[CS_Matt]

fast and furious:
like when the cop guy is gettin NOS for this big race

"i want one of those, the big ones, no better make it 2"

like having 2 huge nos bottles will increase the speed lol
hes gonna fire a couple of shots in a race so the large 2 bottles are just weighin the car down........ GENIUS

 

[Tom]

i know its all wrong!!

 

[petes]

Jeff - you brake with most of your foot, and blip the throttle with the outside of your foot by rolling it to the right (or blip it with your heel, depending on how supple you are).