Double clutching?

carzony

I was watching the 'fast and furious' movie here the other night and it mentioned a lot of 'double clutching' I was curious:P so I went on the web and read up about it but it said in a lot of the articles that it's not actually necessary to double clutch in a modern vehicle? is that true?

According to the friends and the film it seems to make you go a lot faster? I'm was wondering what's the point I aint done a lot of racing but couldnt you just shift down a gear?:eek:

BostonB

I think you are talking about straight cut gears vs helical /synchromesh gears.
Race cars might have straight cut gears I assume that's the idea in movie.

http://automotivethinker.com/transmission/dog-engaged-transmissions-aka-the-crash-box-and-dog-box/

challengemaster

Unless your car somehow has no syncromesh between gears, then you may as well be making engine sounds with your mouth for the amount of difference it'll make.

It _might_ be used during racing outside of racing gearboxes with no syncro (if you have no idea what you're doing and are in the wrong gear mid-corner) , but tbh I'd say heel and toe would be much more commonly used, and much more suited.

Esel

I thought it was either a technique used either for monster trucks or (as said above) non-synchromesh gearbox cars (i.e vintage cars).

Maybe you are thinking of the technique of matching engine revs during downshifts?

Photoshop

I Power shift all the time, much better than double clutching

Who needs a clutch

carzony

http://www.youtube.com/watch?v=pI3cHXnGEx4

This is what I was talking about?

Esel

carzony wrote: »

http://www.youtube.com/watch?v=pI3cHXnGEx4

This is what I was talking about?

As I thought then...

Esel wrote: »

Maybe you are thinking of the technique of matching engine revs during downshifts?

Can't see why you have to press the clutch twice though. Just keep it in while you blip the throttle.

langdang

Gets old, very very fast, on a daily drive. And that was with just one gear that the synchro was fecked.

Dartz

Handy if you want to slip into first. Can be tough on some boxes to get into first when moving, Double clutch and shoe help takes the load off the synchro and makes it easier to slot in.

At least on my car.

As to why you'd do it.... there's a set of traffic lights on my morning commute at the top off a steep hill, and if you time it right and crawl up to them slowly in first you can sometimes make it through without having to stop on the hill because they'll turn green. And it's easier to maintain low speeds uphill in first. Then just stomp to accelerate as opposed to ****ing around with hillstarts.

Doesn't always come off, but when it does it's handy.

shooter88

Must be a lot of gear boxes getting blown not using a clutch to change gear..
Don't believe everything you see in a movie,in fast and furious the cars must have at least 8 or 9 gears you see them in 4th near flat out but still have 5gears to go

Leonard Hofstadter

Photoshop wrote: »

I Power shift all the time, much better than double clutching

Who needs a clutch

The powershift gearbox that you're using has not one but two clutches :pac:.

BostonB

I've not seen the movie. But a quick Google suggests its just techno babble. As Esel said, you'd only use it on downshifts anyway. My dad used to talk about driving trucks with it in the 50/60's.

antodeco

It's probably just double gearing as such. In 5th, straight down to 3rd, upto 4th straight down to 2nd etc

MetzgerMeister

So you consider yourself to be "granny shifting and not double-clutching like you should?" :P

Don't forget though:

mickdw

The full double clutching was required in old trucks etc or you wouldnt get a gear.
Driving anything modern, anything more than rev matching via heel toe doesn't make alot of sense.

Supergurrier

Fast and the Furious where a manifold failure makes a plank fall out the bottom of your car ?

Haha

CJhaughey

Supergurrier wrote: »

Fast and the Furious where a manifold failure makes a plank fall out the bottom of your car ?

Haha

The plank is still in the car, holding the steering wheel.

dgt

carzony wrote: »

I was watching the 'fast and furious' movie here the other night and it mentioned a lot of 'double clutching' I was curious:P so I went on the web and read up about it but it said in a lot of the articles that it's not actually necessary to double clutch in a modern vehicle? is that true?

According to the friends and the film it seems to make you go a lot faster? I'm was wondering what's the point I aint done a lot of racing but couldnt you just shift down a gear?:eek:

There's your problem....

Used with gearboxes that don't have syncromesh to synchronise the gears to the road speed when changing up or down. As said before, gets very tiresome very quick!

Here's what it sounds like when done properly :cool:

https://www.youtube.com/watch?v=-Lbs_nYW3-o