Good Video of Up/Down Double Clutch Shifting - The Unofficial BMW M5 Messageboard (m5board.com)

Lobo · 1st January 2007, 11:20

"Heel & Toe + Double Clutching/Rev Matching with Gary Sheehan A video well worth studying!" - Streetfire.net

This video was originally posted on streetfire.net on July 07, 2006 so there is a chance people have already seen it. I apologize if this is a repost.

Yankee802 · 1st January 2007, 12:34

Ok, I think I'm a pretty good driver, but I guess I don't really understand the whole double clutching thing....anyone care to enlighten me?

Reasons, benefits?

Stealth · 1st January 2007, 12:45

The reasoning behind double clutching is to save your clutch now-a-days, it used to have to be done to save the gearbox, it's not the case anymore as the boxes have syncro meshes which illiminate the requirment to double clutch

you now double clutch to bump the revs up to what the lower gear would need i.e. 60mph in 5th = 4000rpm & 60mp in 3rd = 5500

If you jump from 5th to 3rd you double clutch to get the revs up to 5500 before you engage 3rd gear, this lessons the strain on the clutch, flywheel and drivetrain in general

I hope that is right and helps..... that's my understanding anyway

I double clutch when I drive but my heel toe isn't spot on, so I push the break and roll my foot on to the accelerator to bump the revs while still breaking (kinda hard to imagine) but it works well for me having clown feet

Yankee802 · 1st January 2007, 13:30

Is double clutching recommended if you step down the gears sequentially, and/or if you're mildly aggressive and not racing?

Stealth · 1st January 2007, 14:04

I ALWAYS double clutch going down the gears whether it be sequentially or block shifting, unless the car is in a high gear at low speeds where double clutch isn't needed because the revs are virtually no higher.

I don't double clutch upwards

This is just force of habbit though from driving Jap cars where the gearing is stretched and the difference from one gear to the next is rather large.

jclyman · 1st January 2007, 17:55

Gentlemen, or should I say Gentlemen and Ladies, double clutching is for cars without synchromesh ... like my first car ... a Ford Model A (and, for a while cars had no synchros in first gear and no one needs synchros in reverse).

Because I learned that way, I still double clutch ... good habits are hard to break, as well.

Today, it is totally unnecessary ... and, it does nothing for the clutch (it may wear out the throwout bearing a little faster ... but, a minor effect).

However, I highly recommend learning to do it and to do it ... as;

1. It will smooth your downshifts ... you don't need it upshifting.
2. It will put LESS wear on your synchros, which on cars that reach high mileage, could be a blessing.
3. Depending on your driving prowess, it may allow longer life for your clutch.
4. It is more fun (sporty) to drive that way ...

Why doesn't it affect the clutch? Because if you drive (shift) smoothly, you rev your engine while in neutral to match the speed of engine and transmission (or let it drop a little on upshifting), anyway, if the speed is perfectly matched, the clutch will suffer NO wear ... I can perfectly match speeds nearly always.

To learn, first pay attention to revs in two adjacent gears ... like (at the same road speed) 3000 RPM in 2nd is 2000 RPM in 3rd (just an example and is probably not true with M5 ratios). And, there are charts you can study.

Then maintain a constant speed to drive at 2000 in 3rd, then press the clutch, shift to neutral, rev the engine to 3000, press the clutch while holding that engine speed, then shift into 2nd, and release the clutch.

It will be crude for a while, until you get the hang of it. It you are really GOOD, you can do a quicker double clutch (actually you only use the clutch ONCE) downshift ... Back off the gas ever so slightly, shift to neutral (WITHOUT releasing the clutch ... there is a moment when this works without effort), rev, press the clutch pedal, shift to the new (lower) gear and release the clutch. You can skip gears after some practice. You will have to listen to the engine to get it right.

DON'T EVER HIT THE LOUD PEDAL UNITL the clutch is fully engauged. Otherwise, it soon fries the clutch.

On upshifts, just let off the gas slightly (practice is important here as well), but hold the gas open some (as much as needed in the next gear).

For many drivers it is not worth the effort, but when you become experienced with this techinque, no one in the car will ever feel a down or an up shift. It is just that smooth. In fact, I can shift without depressing the clutch at all, with the transmission shifting very smoothly into the next gear.