SBAD

Getting caught-up in semantics. My chief driving instructor, Vic Elford called it that, and here is an explanation from a British car site.

https://www.carwow.co.uk/guides/glos...clutching#gref

Fishah

We know what double clutching is, but you don't need to double-clutch to rev-match or to do high performance driving. Double clutching was required for non-synchromesh transmissions, like the cars Vic Elford drove in the 60s... But this is a whole new world.

SBAD

Agreed!

SBAD

I get your point, but synchro transmissions are not bullet proof and if driving aggressively true double clutching protects your transmission over time. There is a reason that 2nd gear synchros fail across so many cars.

AlterZgo

This is my 2nd manual with auto rev matching. My first was my F80 M3. Both the 992 and F80 M3 auto rev matches flawlessly. As one who learned how to manually rev match my downshifts early on and who did it religiously for 35+ yrs in my manual cars, it is very easy for me to switch back and forth btw manually rev matching and using the auto rev matching feature. It takes zero time to get used to IMO and no different than switching btw automatic and manual equipped cars. You just intuitively know what to do depending on what mode the car is in. And, to be honest, even if I were to blip the throttle when auto rev match is on, it's no big deal really. I have not found it to over rev at all contrary to what some others have said. It still rev matches perfectly even if I were to manually blip the throttle w/ rev matching turned on.

SamD

I was taught to never use graduated clutch engagement to slow the vehicle. Downshift, matching engine and car speed to minimize clutch wear, and then let the drag of the engine revs do the work of reducing speed. Is this not accurate?

AlterZgo

You're correct. However, I would guess the vast majority of people who are taught how to drive a manual transmission (pre auto rev match days) were never taught how to rev match. I know I wasn't and basically experimented and learned on my own. My son, who learned how to drive stick on these modern auto rev matching manuals, couldn't do it manually if his life depended on it. I've tried to get him to learn but he has no interest in learning how to manually rev match when the auto rev match works perfectly.

spdracerut

In sport or sport plus, the auto blip turns off if you turn PSM all the way off. This is how I drive on the street because I double clutch my downshifts on the street. On the track though, I stay in PSM Sport and let the car do the rev matching. Been tracking cars and motorcycles for two decades, but can't beat the computer. The auto blip really lets me focus on just mashing the brake to threshold.

Ikone

Pushing on the gas pedal to get the RPM up is not double clutching. It's rev-matching.
And, no it's not semantics. It's using proper terminology.

spdracerut

I think most of us in this thread understand this?

Double-clutch: Push in clutch, shift to neutral, let clutch out. Now the engine is connected to the input shaft of the transmission. Blip throttle which brings up the speed of the input shaft to match (edit: speed of the input in ratio to the output determined by the gear ratio of the gear being selected, input and output don't spin the same speed except when the gear ratio is 1:1 which was traditionally fourth gear back in the day) that of the output shaft in the shorter gear. Clutch in, move shifter into next gear, clutch out. Reduces wear on synchro by more closely matching input and output shaft speeds in the trans. Don't have time for all that when doing max braking and downshifting 2-3 gears in the braking zone on the track, so I let the computer do the simple rev match and let the synchros do all the work.

Fredeee

Wonderful. I’ve been driving a manual wrong for decades and it takes a $200k+ car to be awakened to the right way . Time to relearn. I ask for patience but there’s such great info here I think I’ll nail it with some clarification. The auto-blip feels strange because the engine revs when I engage the lower gear BEFORE I pull off the clutch. It’s been a while manual driving a sports car, my other stick is a ‘14 Jeep Wrangler with 37 inch tires and lifted 6” so not much to go on. Can someone please outline the proper steps to shift on a 911 in Sport/Sport+ with auto-blip on? My current process driving along in 4th and wish to downshift to 3rd:
- clutch in
- shift from 4th to 3rd gear
- feather clutch and gas to smooth out shift to 3rd

Easy peezy. Now the right way?

- clutch in
- rev engine quickly (tap the gas)
- shift from 4th to 3rd gear
- clutch out

Can’t thank you all enough for the guidance.

jhenson29

You shouldn’t need to feather if it’s rev matched. You need to feather when it’s not matched.

Try just letting the clutch out after you hear the revs go up on your downshift. It should feel pretty smooth. You can’t wait long though, or the revs will drop and it’ll jerk if you don’t either feather or rev match again (manually or auto).

CanAutM3

The better way:
-clutch in
-blip the throttle as you shift from 4th to 3rd gear
-clutch out

Fishah

With the auto rev match, you have to release the clutch very quickly after it revs... Otherwise the revs fall back down and it was wasted.

spdracerut

Keep in mind it's for track use, so think 'fast'. Clutch in, shift, clutch out, no more than a half second from clutch in to clutch out.