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Posted: 08 Mar 2007 12:59 am
by A M R
what kind of a sound does double de clutching make?

better than blipping the thottle when going through the gears while braking hard?

Posted: 08 Mar 2007 03:33 pm
by jtbo
Actually I always rev match and use heel&toe, saves clutch and is much nicer, specially with MS as there was quite strong engine braking so you really had to rev match or you found that your nose just met windscreen in case of 1st or 2nd gear :lol:

Car must also be perfectly stopped in order to put reverse gear in, or it will crunch and protest as you are pushing two gears against that are rotating completely wrong direction.

I have new clutch and surely I do have to push it all the way to bottom when putting reverse gear in, with other gears don't need to push pedal a lot at all.

Posted: 08 Mar 2007 06:25 pm
by MJ
Double clutching doesn't in itself make any noise, but what you do with the engine at the same time would. It's just releasing the clutch in neutral, and then depressing it again before selecting the gear you want and letting it back up again.

I'm no expert on drivetrains, but is the idea of double clutching to match the speed of the propshaft and gearbox input to the gearbox output and wheels? Is there enough momentum in these parts to keep them spinning long?

I mean it's obviously not engine speed as you can do that without double clutching.

Posted: 08 Mar 2007 06:41 pm
by jtbo
Watching movie called Bullit can help to hear how it sounds when done by a pro, it is two blips instead of one that he does.

Posted: 08 Mar 2007 06:53 pm
by MJ
And it's done in a Mustang :D

Cliffs note: Several different Mustangs were used in the street jumping as they broke suspension parts, but the car he was chasing (was it a Dodge Charger, or Challenger or something?) survived the jumps :)

Posted: 08 Mar 2007 07:01 pm
by A M R
i usually use heel-toe when im downshifting and braking hard. gearshifts are soooo smooth and it sounds the bollocks!

but the brakes on mums punto fade quickly...(and smoke after a hard run)

wouldnt double clutching and blipping the throttle twice give the same effect as heel-toe except take longer?

Posted: 08 Mar 2007 07:37 pm
by jtbo
A M R wrote:i usually use heel-toe when im downshifting and braking hard. gearshifts are soooo smooth and it sounds the bollocks!

but the brakes on mums punto fade quickly...(and smoke after a hard run)

wouldnt double clutching and blipping the throttle twice give the same effect as heel-toe except take longer?
You should note that in cars where double clutching is needed you just can't heel and toe as you need really do double clutching or you will end up lot of bad noise and pain in hand as gear stick hammers your palm with quite good amount of force, try to drive old truck and you will learn that :lol:

I can heel & toe without driving hard, I'm good 8) lol

Posted: 08 Mar 2007 08:16 pm
by Nick C
The idea is indeed to help match the speeds, more commonly used on older vehicles without synchromesh boxes.

if in doubt - ask Wikipedia:

http://en.wikipedia.org/wiki/Double_declutch

Posted: 08 Mar 2007 08:41 pm
by A M R
well i know its for cars without synchro's, but what use is it on a modern car?

Posted: 08 Mar 2007 08:46 pm
by jtbo
A M R wrote:well i know its for cars without synchro's, but what use is it on a modern car?
As stated earlier clutch may get bit stuck on shaft and then doing double clutching usually helps get it moving. Proper cure is to apply some grease to it (try to avoid friction surface and flywheel though ;) ).

Posted: 08 Mar 2007 08:48 pm
by A M R
oh right. sorry should have read the thing properly.

Posted: 08 Mar 2007 09:26 pm
by germ
i was told by a great racing driver that if you cant double de clutch your not a real driver

double declutch makes less ware and it takes no more time if your good you can do it extreamly, quick even quicker


the sound i talk of is the slowing of engine then the blip and slowing again cant explain anyway i just like thats all

and if you have the gear changing problem (as some have here) where you cant easily get a lower gear doulbe declutch helps



most people dont even know what it is let alone how to do it :roll:

Posted: 13 Mar 2007 01:47 am
by foggyjames
Just to add a bit of fuel to the fire...I left my 360 standing for about 3 months over the winter, and when I came to drive it, it was very tough to get into 2nd, and especially first and reverse. It would grind reverse every time, and badly at that. It also felt very 'stiff'. After about 5 miles, it was completely back to normal. I'm putting that down to the gearbox oil having completely settled in the bottom of the casing, and the box effectively running dry in places.

cheers

James

Posted: 13 Mar 2007 09:27 pm
by pettaw
Nah it was the clutch seized onto the splines, meaning it doesn't disengage and the gearbox just won't stop spinning. My red car does it routinely.

Reverse grinds because there's no synchro and first is a pain because you're forcing the gearbox to stop using the synchro ring in the gearbox.

It trying to get into reverse the gearbox stops rotating ie: no grinding, it just simply won't go into gear, then it could be that the gearbox cogs have just finished in the wrong place, so clutch up and down again will cure it.

Posted: 13 Mar 2007 09:49 pm
by foggyjames
Ah yes, that would make more sense really. It'd be a dead giveaway if we could see the prop like on a 2/7/9 :)
pettaw wrote:[If} it just simply won't go into gear, then it could be that the gearbox cogs have just finished in the wrong place, so clutch up and down again will cure it.
Yup....quickly 'realigning' the shaft usually sorts it out. Both cars 'try' to grind relatively regularly, but they'll only actually do it if you rush them. Stopping, rotating the shafted (clutch up in neutral), then going 2 > 1 > R will usually prevent any grind at all.

cheers

James