Cursed by the double-clutch

[David N.]

Double-clutching downshifts. Seemed like a good idea. Save a tiny bit on the clutch, preserve the synchros a little bit. Get that awesomely smooth in-the-gate feel from the stick. I do it for a few weeks, now I have a problem. I can't single-clutch a downshift any more.

Blipping the engine with the clutch in feels really wrong now, it's horrible. Obviously upshifting without double-clutching isn't too difficult, since you're not having to hit the gas with the clutch disengaged. But to downshift I have to think about it completely to do it. Then I make contact, feel how off the rev-match was, think about that poor clutch plate and curse the day I learned stick.

Anyone ever in that sort of situation?

[NickCats]

David,

You perplexed me with this thread so I had to look it up ( from wikipedia ) :

However, in order to downshift, engine revs must be increased while the gearbox is in neutral and the clutch is engaged. This requires the driver to shift into neutral, release the clutch pedal, apply throttle to bring the revs up to a suitable speed, depress the clutch again, and finally shift into gear. This operation can be very difficult to master, as it requires the driver to gauge the speed of the vehicle accurately and is often conducted as cars in front slow down.

So, how long did it take you to master this ? Sounds tricky...

Nick

[David N.]

Hey Nick. It's pretty easy really, it spreads out the shifting process through more steps, and in a way simplifies it because you'll never really need to precisely vary both feet at the same time. Easy practice is to downshift and upshift while cruising and try to get the revs exact and the stick to slide into the gate with no resistance at all. I guess I worked at it for a week's work of driving before I didn't have to think about it.

At the end of the day it's not really that handy for performance driving, it's obviously more steps and takes a lot longer. It's just nice because it seems to be easier on the tranny.

[John V]

Originally Posted by David N.

Hey Nick. It's pretty easy really, it spreads out the shifting process through more steps, and in a way simplifies it because you'll never really need to precisely vary both feet at the same time. Easy practice is to downshift and upshift while cruising and try to get the revs exact and the stick to slide into the gate with no resistance at all. I guess I worked at it for a week's work of driving before I didn't have to think about it.

At the end of the day it's not really that handy for performance driving, it's obviously more steps and takes a lot longer. It's just nice because it seems to be easier on the tranny.

Waste of time and energy. You'll never double clutch a synchro box as fast as the synchros can do it, unless they're worn.

Let the synchros do their job. They're very durable in these transmissions, and they're there to help ya.

[MNBoxster]

Originally Posted by John V

Waste of time and energy. You'll never double clutch a synchro box as fast as the synchros can do it, unless they're worn.

Let the synchros do their job. They're very durable in these transmissions, and they're there to help ya.

Hi,

I agree that today, you don't need to do it, but it's still a good skill to master. Anything which makes you a better driver is worthwhile IMHO.

While the synchros will do the job, I feel it's especially important learning how to match revs for downshifting, this will really preserve both the Box and the Clutch, the Clutch in particular.

And, you never know, you may aspire to Auto-X (rev matching keeps the engine in the sweet spot, an aid toward improving your ETs) or Race someday, and not all race cars have a synchro transmission. My old Formula Ford didn't - straight cut Dog gears. You either double-clutched, or spent your time fodding the Track picking up pieces of your broken tranny...

Happy Motoring!... Jim'99

[John V]

Originally Posted by MNBoxster

Hi,

I agree that today, you don't need to do it, but it's still a good skill to master. Anything which makes you a better driver is worthwhile IMHO.

While the synchros will do the job, I feel it's especially important learning how to match revs for downshifting, this will really preserve both the Box and the Clutch, the Clutch in particular.

And, you never know, you may aspire to Auto-X (rev matching keeps the engine in the sweet spot, an aid toward improving your ETs) or Race someday, and not all race cars have a synchro transmission. My old Formula Ford didn't - straight cut Dog gears. You either double-clutched, or spent your time fodding the Track picking up pieces of your broken tranny...

Happy Motoring!... Jim'99

Well, rev matching and double-clutching are two completely different techniques. Rev-matching is, as you say, crucial to smooth and fast driving. But rev matching isn't about keeping the engine in the "sweet spot." Rev matching is only done to reduce the load on the clutch when shifting to a lower gear - think using your clutch to engage 2nd gear at highway speeds with the engine at idle. Would you rather use the clutch friction to increase the engine speed or use the throttle? I think you'd rather use the throttle, and that's rev-matching.

Double-clutching, in a synchro box, will just slow down your shifts and is a waste of time and energy.

I do know a thing or two about autocross as I do about 20 events a year including multiple National Tours / ProSolos and the Solo Nationals. I've only downshifted once in the past three years!

[MNBoxster]

Originally Posted by John V

Well, rev matching and double-clutching are two completely different techniques. Rev-matching is, as you say, crucial to smooth and fast driving. But rev matching isn't about keeping the engine in the "sweet spot." Rev matching is only done to reduce the load on the clutch when shifting to a lower gear - think using your clutch to engage 2nd gear at highway speeds with the engine at idle. Would you rather use the clutch friction to increase the engine speed or use the throttle? I think you'd rather use the throttle, and that's rev-matching.

Double-clutching, in a synchro box, will just slow down your shifts and is a waste of time and energy.

I do know a thing or two about autocross as I do about 20 events a year including multiple National Tours / ProSolos and the Solo Nationals. I've only downshifted once in the past three years!

Hi,

Yes, of course you're right, double-clutching and rev-matching are two different things. I guess my post was more to encourage people to match their revs than to double-clutch anyway. But by double-clutching, you master that technique of stabbing the throttle and matching the revs, as the Lister said, without even thinking about it...

Happy Motoring!... Jim'99

[Perfectlap]

this sounds like a....you guessed it YOUTUBE momment!

I saw this one a while back I think its Sebring.

http://youtube.com/watch?v=0j-3xIZK-Bk