Rev Matching. Yes or no?

[porphyre001]

Why would you double declutch on a synchro 'box?

It's easier on the synchros. Skipping gears, like a 4->2 or a 6->3, has a bigger RPM differential than a standard gearchange. If you re-engage the clutch while in neutral and you blip, all the bits and bobs get up to speed, rather than the synchros on the 2nd gear accelerating everything.

But mainly, it feels good to do and it's a skill not everyone has. This is exactly the "driving engagement" argument people make for a manual transmission instead of the A10, even though cars equipped with the A10 are quantitatively faster cars.

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[Terminus]

No, turned it off day one!

 

[Motoguy]

I use it because, 1) I am pretty new to manual shifting and 2) I want to protect the MT82 that doesn't like mis-matched rpms on the down shift and who's synchros are generally not too robust.

 

[GrabberB]

Driving a vehicle with a manual transmission is second nature to me. My Mustang is manual and i use it all the time. Many full on race cars today have a form of rev match. How it controlled may differ but the end result is basically the same. Rev, match is not just for rookies. Professional drivers use it too.

 

[LouG]

It matches engine speed. I turned off Rev Matching because I don't always select the next gear in the sequence of down shifting. I might want to decide what gear I want for the situation.

OK. But it's not necessary. Heel and toeing with extra revs for skipping gears does the job and the synchro cones take car of minor gear speed differences.

 

[LouG]

It's easier on the synchros. Skipping gears, like a 4->2 or a 6->3, has a bigger RPM differential than a standard gearchange. If you re-engage the clutch while in neutral and you blip, all the bits and bobs get up to speed, rather than the synchros on the 2nd gear accelerating everything.

But mainly, it feels good to do and it's a skill not everyone has. This is exactly the "driving engagement" argument people make for a manual transmission instead of the A10, even though cars equipped with the A10 are quantitatively faster cars.

As I said to another poster, all the driver needs to do is match revs to road speed, heel and toeing does that on downshifts. The synchros are there to match actual gear speeds.
What double declutching does is trade insignificant syncho wear with double the work on the throw out bearing and pressure plate diaphragm.
But, if you like doing it, keep doing it.

 

[LouG]

Slightly off subject, but my wife loves how the automated manual works in her new car.
Real, proper downshifts like some skilled human is doing them. A bit like track mode in the Mustang but with a more pronounced rev match.
Upshifts require a bit of throttle finesse, but I'm surprised how quickly she adapted.
Once again, you can't really go by internet car "experts" who all bagged this set up.

 

[Charger68]

OK. But it's not necessary. Heel and toeing with extra revs for skipping gears does the job and the synchro cones take car of minor gear speed differences.

Double clutching isn’t necessary, but heel and toeing is a PITA. I drove stick since 1970, and all this discussion is pure opinion. I rev match, double clutch, power shift, and once in a blue moon shift without clutching. I’m just happy to drive.

 

[porphyre001]

As I said to another poster, all the driver needs to do is match revs to road speed, heel and toeing does that on downshifts. The synchros are there to match actual gear speeds.
What double declutching does is trade insignificant syncho wear with double the work on the throw out bearing and pressure plate diaphragm.
But, if you like doing it, keep doing it.

Tell us you've never overhauled a transmission without telling us.

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