Is double-clutching necessary...

[SKiM3]

... for a down-shift rev-match in a 6MT? I read that double-clutching is no longer necessary on newer manual cars, especially the M3 since the gears are synchronized (no idea what that means). Is this true? If so, is it safe on the drive-train/clutch to down-shift this way?

1) Press clutch
2) Drop to lower gear
3) Rev-match by pressing gas
4) Release clutch
5) Hit gas and go.

Or is there a better/proper way? Sorry for the newbish question, but I am somewhat a newb to manuals. Flame if you wish.

Thanks!

[Grail05]

[Psylight]

There are mad threads on this topic, but....if it helps, the way you listed is the way I revmatch.

[Erhan]

Originally Posted by SKiM3

... for a down-shift rev-match in a 6MT? I read that double-clutching is no longer necessary on newer manual cars, especially the M3 since the gears are synchronized (no idea what that means). Is this true? If so, is it safe on the drive-train/clutch to down-shift this way?

1) Press clutch
2) Drop to lower gear
3) Rev-match by pressing gas
4) Release clutch
5) Hit gas and go.

Or is there a better/proper way? Sorry for the newbish question, but I am somewhat a newb to manuals. Flame if you wish.

Thanks!

What you describe is rev matching down shift. Double clutching is a little different, and as you stated is not necessary unless you're shifting down to 1st. I believe M3 like many other cars don't have syncros for 1st gear.

If you think about gears, you're going from one ratio to another, which means they will be spinning in different rates for a given speed. So you have to make sure gears spin at the same rate via double clutching.

In modern transmissions, the gears are always in contact (ie, synchronized), so you don't have to worry about this.

For better explanation, refer to wiki:

http://en.wikipedia.org/wiki/Manual_...d_transmission

[Prince_of_Persia]

I rev match the same way you described. I don't think double clutching is necessary.

[disapr]

The DCT cars rev match.... Just sayin.

[Radiation Joe]

Originally Posted by erhanh

.... I believe M3 like many other cars don't have syncros for 1st gear.

....

LOL!

The last thing I drove that didn't have 1st gear synchronizers was 1974 Ford F-250 with a "granny low" 1st gear.

Double clutching really only helps with the speed of downshifts. It does save a little wear and tear on the syncros, but can do some harm if done incorrectly, e.g. mismatched speeds when engaging the gear. I double clutch about 25% of the time. Usually, just to have a little fun.

[Erhan]

Originally Posted by Radiation Joe

LOL!

The last thing I drove that didn't have 1st gear synchronizers was 1974 Ford F-250 with a "granny low" 1st gear.

Double clutching really only helps with the speed of downshifts. It does save a little wear and tear on the syncros, but can do some harm if done incorrectly, e.g. mismatched speeds when engaging the gear. I double clutch about 25% of the time. Usually, just to have a little fun.

Hey thanks for correction... For some reason I always thought the 1st gear don't have synchros..

[KGB7]

I straight up triple clutch bro.

[Erhan]

Originally Posted by KGB7

I straight up triple clutch bro.

[GT3 Tim]

Nice vid. LOL. Triple clutch? Wtf? ROTFLMAO!

All he is doing is slipping the clutch....which will beat the sh!t out of it.

The only time you need to double clutch is when driving a big-rig, or maybe when going to first.

[ChipB]

Originally Posted by SKiM3

...
1) Press clutch
2) Drop to lower gear
3) Rev-match by pressing gas
4) Release clutch
5) Hit gas and go.

What about the brake? The only thing I would add is step (0) which is "press the brake with the ball of your foot," and on step (3) you rev-match by blipping the throttle with the outside of your foot while continuing to press the brake with the ball of your foot. This is heel-and-toe downshifting. It takes some practice to make it smooth, but allows for quicker deceleration than simple rev matching does, and avoids some wear and tear on your clutch. The reason you down-shift in anticipation of a corner coming up shouldn't be to slow the car, but rather to be in the proper gear for when you start to apply the gas as you turn in to the corner.