Originally Posted by EBMCS03' post='248955' date='Mar 2 2006, 07:10 PM

And on the DB9 note... I think it was a SMG type gearbox wasnt it? so thats why he said whatever he said...
Oh and not just the M5 Rev matches... regular cheapie production SMGs rev match too.

Originally Posted by ipse dixit' post='248989' date='Mar 2 2006, 10:54 PM

After all, rev-matching can be found on lots of slushboxes ... even a cheapie auto gearbox in the Infinit G35 rev-matches on downshifts (does it pretty well too).

Originally Posted by jet190rs' post='249007' date='Mar 2 2006, 08:21 PM

Dude! When I drove the Infiniti M35 and downshifted, the clutch was fried! :thumbsdown:
http://forums.e60.net/index.php?showtopic=22879

Originally Posted by sdente' post='248892' date='Mar 2 2006, 08:15 PM

You are all partialy right. Double clutching was a technique designed to enable smooth downshifts and prevent gear damage. Double clutching was and is used for downshifting cars with straight cut gears and no syncros. These days all street cars and almost all race cars have syncro transmissions so true double clutching is not required to protect the transmission. However, when driving at the limit of a car it is still neccesary to match the revolutions of the engine to the speed the wheels are turning in order to not upset the balance of the car when you engage the gear. You do this with the heel/toe method as follows.

1.) Begin braking
2.) Depress the clutch with your left foot
3.) While keeping the brake depressed with the toes of you right foot you use the heel of the right foot to depress the throttle (blip) so that the engine RPMs exceed the point you need to match the revs of the wheels. As you release the throttle you also release the clutch.

This results in a down shift that does not upset the car and puts no strain on the transmission.
When done right you will not feel the car speed up or slow down due to releasing the clutch. You will never be a quick driver until you master this technique.

I am always amazed by drivers who slam the car down a gear making lots of noise while using the engine to slow the car down. Engine and transmissions are expensive compared to brakes. Remember, the only reason you downshift is to ensure you are in the proper gear to accelerate after you are done braking.

Here is a link to a video that show Heel and Toe done properly
www.radicalmotorsport.com/gallery/mv_feet.mpg

Enjoy!!!!

Originally Posted by jet190rs' post='248985' date='Mar 2 2006, 10:49 PM

I guess its a British thing, or maybe just a Jeremy Clarkson thing...but he should've said it "blips the throttle" or "rev matches" or maybe even "heel and toe" instead of "double de-clutches". These are the correct terms in American English.

BTW, we also just say "double clutch" instead of "double de-clutch"

Originally Posted by BetterMakeWay' post='249100' date='Mar 3 2006, 09:47 AM

That might be the explanation.

Originally Posted by needforspeed' post='249104' date='Mar 3 2006, 05:03 AM

What Clarkson meant was that the DB9's gearbox was clever enough to replicate the effect of heeling and toeing and I believe he called it double de-clutching cause he is a proper old fashioned brit.

Originally Posted by BetterMakeWay' post='249128' date='Mar 3 2006, 10:43 AM

Yes...and i ask again: what auto desn't do that now? My steptronic also does that. Why did he say that gearbox is so special? Maybe because he said that the sequential gearbox in the vanquish is rubbish and it doesn't work and it brakes all the time.