Mine works smooth as silk, with a double-clutch down-shift and I can't imagine that it is harmful when it is that smooth and is no where near over-revving. I generally wait until I'm nearly stopped to down-shift to first if I can't double-clutch. Admittedly, this practice goes way back to the time when I learned to drive in VW bugs during the days when first gear wasn't synchromesh. I'll be watching to see what the experts (here) have to say on this topic. Is this a bad habit that I should unlearn, or a method that helps me reinforce a driving skill and makes driving more enjoyable?

 

The higher the effort of the shift, the more wear on the syncro's. Wait till your going really slow to shift into first if its just a stop sign (or you could do the whole double clutch thing, but thats kinda a pain). Otherwise, I use first on tight bend on spirited drives, this is a sports car after all; if 1st gear wasnt meant to be downshifted into it wouldnt need a syncro.

 

Good catch and I agree.

 

Wow, a double clutch downshift. I've never tried that before- only on the upshift. I wonder how slow my shifts would be if I started trying this.

 

^ say what??? a double clutch is also known as rev matching........ there's no need to do it on an upshift.. (thats why we have syncros).... it's only needed when downshifting...... heal toe is relatively the same thing as double clutching/rev matching....

 

No, your confused, rev matching and double clutching are seperate things. A rev matched downshift goes like this: Clutch in, Rev engine to desired RPM while shifting, Clutch out. Double clutching would be this: clutch in, shift to neutral, clutch out, rev engine to desired RPM, clutch in, down shift, clutch out. YOu engage the clutch twice, hence the name "double clutch."

 

wasted motion....... thats the same as...

clutch in, shift to neutral, rev engine, down shift, clutch out...... you can hold the clutch down the whole time.... it is not nessecary to let the clutch out when in neutral.......once you're in neutral it doesn't matter if the clutch is in or out... you're still in neutral....

and rev matching is the same thing as double clutching.....
http://www.felixwong.com/openroad/double_clutch.html
read first sentance in second paragraph.... double clutching also known as "matching revs"
however he does mention the clutch out while in neutral.. but i think it's a wasted motion......

 

Caffeinated his it right- double clutching and rev-matching are two different things. It doesnt matter NOW because we have synchros to match the engine speed to the output shaft (someone correct my terminalology here). These two would be rotating at different speeds and the synchros take care of how these mesh together. I dont know the exact mechanics of it, but, when you clutch out after neutral and then rev match then clutch in, engage gear, then clutch out the output shaft should be spinning the same speed as the engine. Back before they had synchros, double clutching was a very necessary thing for proper manual driving technique. I agree that, with a car with syncros it is wasted motion, but it would be fun to learn.

 

Double clutching is more important on down shifts than up shifts. Double clutching and rev matching are two different things. Double clutching does involve letting hthe clutch out in nuetral and either speeding up or slowing down the clutch and main gear to match the next gear engagement (up or down).

On an upshift, as you shift, the engine speed is dropping and at some point will match the correct speed for the next gear.

This concept id easiest to comprehend if you look at a pictorial diagram of the clutch and transmission assembly. I think one of the sites that depicts this is howthingswork.com.

 

When you put the clutch in and engage the next gear, the synchros bring the clutch plate and mainshaft to the speed of the differential. The engine is disengaged at this point.

That is why if the engine speed is too high, you will chirp your tires, and if the engine speed is too low, you will bounce your passengers head off the windshield .

A person that has been driving a stick shift for a while will be able to rev match so when they let out on the clutch neither one happens.