These "How to shift" discussions are always entertaining... Lol

Double clutching on upshifts? Why? TO speed up the synchros of the lower gear? It's already spining faster than necessary whenever a higher gear is selected... I think it's a waste of time and a potential risk/wear of engaging a synchro while spinning way faster than it would have on a "normal" upshift.

On downshifts, it's usually not necessary, but I do it all the time. Simply because it's better when I'm at the track and I need to skip a few gears. In these moments, I need the gear to get in smoothly with a positive engagement. The regular double clutch downshift trainning pays off then.

In any cases, just drive. Keep your foot OFF the clutch pedal as much as possible and have fun.

 

Amazing!!!

I've been drving manual trannies for over 50 years, and I never know it was so complicated.

And I never knew clutches and trannies were so fragile. I have abused both pretty badly at times, (showing off, racing, pulling trailers, etc) so I can't understand why I have never broken or worn out either one.

bill

 

guys this really isnt complicated, it's simple physics and an understanding of the clutch and the internal workings of a transmission. you dont need to double clutch anymore, you can but it isnt necesary.

and one final point to make about rev matching and how it's a GOOD thing to do is this....

on my last z i bought it and it had a blown third gear synchro (blown when i bought it, i had nothing to do with it), if i downshifted by just putting the clutch in and tried to put it into third it would grind like crazy every time and refuse to go into gear......if i rev matched, it went right in with NO grind and NO hesitation....and that was with no synchro to speak of, so try and tell me that rev matching hurts synchros or your clutch

 

These threads are indeed amusing. Talk about the blind leading the blind.

 

It's because people are talking about 8 different things when they say rev-match or double-clutch or even downshift. But, I'm done with the discussion so have at it.

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

 

Even your wikipedia article is wrong. I think you should have been done with this discussion before you started.

 

Oups. Again, no double clutch is needed when upshifting, even on a synchroless gear box.

 

I got a kick out of the wikipedia article. I think korki wrote it.

 

By double clutch, what do you mean?

Also, it is not necessary on a synchroless gear box because you can just hold the clutch down until the RPM's drop. But I prefer not to hold the clutch down while that happens.

Also, even w/ synchros, double clutch prevents the car from jerking forward when you upshift at moderate-high RPM. The same can be accomplished by holding in the clutch.

KB [Learned to drive on a '69 Ford Truck w/ a synchroless gear box]

 

Jerking on upshifts ? The only way that can happen is if the engine rpm's are out of synch by a fairly large margin. That has nothing to do with the transmission operation. Synchro or not, no matter how many time you hit the clutch before getting in your gear, if your revs aren't right, you'll jerk the car.

Double clutching, like you said somewhere, is used to accelerate the next gear's synchro. When you upshift, you need to deccelerate the lower gear's synchro. No double clutching is necessary or usefull then as it's already spinning too fast.

If your truck needed some double clutch on upshift, I suspect something was badly worn/broken in there.

I've driven synchro-less cars too.

 

We are talking about different things by "double clutching."

I mean placing the transmission in neutral. Allowing the engine speed to drop. Then reengaging the transmission in a higher gear.

For example: If i want to shift from 2nd to 3d, I'll push the clutch in and disengage the transmission, then let the clutch out. Let the engine speed drop by a few RPMS, and then push the clutch in to reengage the transmission.

I don't mean increasing the speed of the synchro in the higher gear. You couldn't do that if you wanted to.

 

Aaah, is your ECU working properly ?

It should take but a fraction of a second for the engine rpm to drop low enough for the next gear. About the time it takes to move the stick to the higher gear.

If anything, I might need to give gas if I waste to much time in neutral. If you have the time to wait in between upshifts, something is not right with your engine management.

 

All this double-clutching must be the reason members are posting 15 second ETs. Too much playing with the damn clutch.

 

I thought that riding the clutch was using the clutch to hold the car on a hill?

 

Don't confuse the kids any more!!!

Yeah, riding the clutch is what you said...

 

learn where your shift points are and dont use the clutch at all

 

I thought "riding the clutch" was driving around with your foot resting on the clutch peddle instead of the dead peddle?

I have a friend with a transmission shop. Send me a PM when you need his number.

 

And we have a wnner!

bill

 

+1

Just drive the car and enjoy it. If the OP is not grinding gears or anything like that, I doubt he is hurting the clutch or tranny. I've never replaced a clutch and I downshift every time I stop. Been driving manuals for over 30 years. If being smooth is what you want, concentrate on that and don't worry about the clutch.

 

do think just do. focus on radio