Team-BHP (https://www.team-bhp.com/forum/)

-   Technical Stuff (https://www.team-bhp.com/forum/technical-stuff/)

-   -   Whats double clutching & whats the reason to use it (https://www.team-bhp.com/forum/technical-stuff/2155-whats-double-clutching-whats-reason-use-4.html)

@Rehan
great info !! thanks a lot &
safe driving!

here are a couple of videos of blipping(heel and toe) or rev matching ,, you need to do this if you're racing a car, we have to do this while driving the fissme's and formula lgb's and i'm told that it's done even in formula bmw's

YouTube - Heel-toe shifting technique

YouTube - Double Clutch Downshifts

Yes when you want to exit a curve that requires a downshift. But it is mostly dependent on the driving style of the particular driver.

hey rehaan realy informative buddy

instead of watching these videos,download the entire drift bible from limewire...it is worth the wait believe me.

not much use in knowing how to drift in india. unless you own a porsche or a bmw or some other rear wheel drive.

and besides, you can blip in any car, even an m800.


neverthless, i'll download the drift bible. (how big is the file)

In India you can actually drift quite a few cars. Padmini included.

Most rear wheel drive indian cars can be drifted..eve if they have lower power..its fun to drift..but one needs to be careful as to not loose control..!

Rehaan..all vintage cars [pre 1950s] did not have synchro and one has to DDC to have a smooth shift..Also..most of these cars were not high speed engines..its just the way those gearboxes were built..

BTW..thats some nice info you have put in there..

i can think of padmini and contessa. but do they have enough power to drift? also would you be able to downshift a padmini in such a way that you can lose the back?

i was around 13 when i last sat in a contessa so i don't remember. i do remember that it was huge. so drifting it in my mind is like drifting a rear wheel drive truck.

i guess it's possible, but you'd have to be very good and you'd need a lot of room.

i'd like to hear if anyone here has tried drifting an indian vehicle, and which roads you did it on. (no e-brake stories of lancers/ikons/etc please, that isn't drifting)

another vehicle comes to mind, the gypsy. i guess you could drift in that.

dude with the new tech of gear box's double clutching is useless
if you do that i feel ull waer out your clutch faster but not gain anything frm it

Im afraid you got it wrong malcolm! Let me explain how.

Double clutching was once a required technique. It was used to sync the engine and transmission speed. In older cars without double clutching you were unable to shift (you even had to double clutch to up shift). However, in new transmissions synchromesh gears do most of that work. While the synchromesh gears reduce the need for double clutching, they don’t handle the large changes in speed that go with down shifts very well. Double clutching makes the downshifts smoother and saves wear on the transmission by reducing the amount of work done by the synchromesh units. So go out and practice a double clutch down shift (in a safe place), it’ll save you precious money on your transmission.

The hardest part is figuring out how much to raise the engine revs. It depends on how fast you’re going and your transmission’s gearing. Got to get that by practice.

I caught up with a video in youtube and practiced double clutching, its fun when you really go out for a fast ride :)

And how do you propose that we 'remove the leg' ?? :D

sorry, couldn't resist !

I have been riding / driving for about 3 decades now. I have seen them all, the constant mesh, the partly syncromesh, the fully syncromesh gear boxes, the 'semi-automatic' (no clutch) boxes, automatics (no gear lever / clutch - UGH!) to the latest 'DSG'.

One thing has not changed over the years - in manual gearboxes, you need to use the clutch in different ways to shift up/down depending on the conditions (vehicle condition, load, road speed, engine speed etc.).

Clutching fell into four broad categories:

1. Normal or single clutch (as one does when starting from stop) - when one wanted to shift up/down one depressed the clutch and shifted from gear to gear (often without halting in neutral).

2. "No clutch" shifts - experienced drivers who knew their vehicles intimately did not depress the clutch at all when shifting up, relying merely on their ears and feel (feedback via the gear lever) to ease the vehicle into one gear from another. Incidentally bus drivers are past masters at this courtesy the light vehicle load and their long hours behind the wheel. Drag racers at signals too used this to move up and down the gears quickly. WARNING - If you do not get it right, you can bust your box or worse, have a bad spill! Downshifting without using the clutch was particularly tricky as one had to match and time the use of brake pedal and gear shift perfectly.

3. Partial clutch - a neat compromise between the first two where the driver depresses the clutch partly to provide a cushion to accomodate any 'margin of error' in matching the engine speeds.

4. Double de-clutching was required only when there was a sticky shift on the offing i.e. the gear lever kinda balked at the thought of moving into another gear, this the driver felt as a resistance in his palm when trying to shift. Double de-clutching was also the method of choice when one had to ensure a fool proof shift eg. on a ghat road or when overtaking at high speed (with a full load) with heavy on coming traffic.

I have used every one of these techniques on the vehicles I have owned - Ambassodar, Padmini, Herald, Lambretta, Jawa, Suzuki-Supra, 118NE, Opel Corsa, I however lay off the no-clutch technique on my Laura as there is no need and, the box is too expensive to replace! :eek:

Good info on this page..and reading the page on How Stuff Works for gears and transmission also helped me understand things better.
One of my friends who owns a swift (abt 2 yrs old/25k kms) gave her car for servicing as the car was making a sound like a jet taking off when she tried to take the car beyond 70-80. The Maruti Service station guys told her that her clutch was worn out and so were the gears and this was probably because she was using the clutch too much while driving (coasting/cruising with the clutch pressed so that the gear isnt engaged).
I dont understand how this can happen. stupid:
If the clutch is pressed, the clutch disconnects the flywheel from the tranny and the wheels/gears move due to the momentum of the car instead of the drive from the engine. How will this wear out the gears? I can understand the clutch's friction plate wearing out because the flywheel and the tranny are now moving at different speeds and this wears the clutch plate out.