Rev matching on upshifting, downshifting, or both?

Do you guys try to rev match your manual trannies on your upshifts as well as your downshifts?

I make a habit of doing that, when I'm accelerating I'll let the clutch out as I depress the gas because I don't like that little herky-jerk you feel as the car changes into higher gears. Naturally, I do the same thing when downshifting too.

I recently had someone in my car though that claimed this light rev matching on the upshifts will wear out the clutch. That seems dubious to me.

i almost always rev match downshifting, but almost never when im upshifting. I doubt it will wear out the clutch any faster, but I also dont think its very necessary to rev match upshift.

how slow do you upshift?
on downshifts i frequently match the revs, but when i upshift, the rpms will drop to wherever they have to be by the time i let the clutch out

Downshifting for sure but usually not upshifting

Rev matching as in letting the clutch out quickly once the rpm hits exactly the right spot? Yea I do that. It's what you're supposed to do. The gas comes on right when the clutch engages, if you don't do that, the car will jerk as the engine is slowing down while the car is still moving foreward. If by revmatching you mean slipping the clutch a bit to get it smooth, try to avoid that on both upshifts and downshifts.

Rev matching is only needed on downshifting.

I've driven a race car without synchronizers in the gearbox so when you were downshifting, if you didn't blip the throttle the transmission would just grind and never go into gear. But upshifting, nothing is needed other than pulling or pushing the shifter into the correct gear. The only case you might need to blip the throttle on upshift is if you miss a gear and take so long that your revs drop all the way down to idle.

When I'm driving on the street, whenever I let out the clutch, I'm slowly getting back on the gas at the same time. Getting this right smoothes things out. But you shouldn't use so much gas so that your RPMs going up as you let out the clutch. You just want to let the clutch slip as little as possible.

Like it has been said, rev match on the down shift.

When doing T/A in the skyline there was a lot of heal toe going on, with a 2 way diff, the car liked to throw itself sideways if you downshifted too quickly. I have not heard of anyone rev matching an up-shift in a modern car. Other than Dominic Toretto "Granny shifting, not double clutching like you should!"

All good drivers double declutch changing down. Get somebody to show you how and practise as much as possible. Great stuff when you get it right and your syncro's will love it.

Do this:
http://videos.streetfire.net/video/H...hing_57431.htm

Originally Posted by pMak26

Do this:
http://videos.streetfire.net/video/H...hing_57431.htm

double clutchin on downshifts ?

is double clutching like clutch in move to neutral clutch out clutch in move to gear clutch out?

nothing wrong with either, though I time my up-shifts to the engine spin down so that I dont have to rev-match. Usually a lazy shift will almost always be smooth. Rev-matching while downshifting is actually better for your clutch. My Corrado went 180K miles on the original clutch because it was always driven properly.

Originally Posted by jailonacs99

I recently had someone in my car though that claimed this light rev matching on the upshifts will wear out the clutch. That seems dubious to me.

This is true. You are riding your clutch in order to have a smooth feeling, but it is not the right way to do so.

My experience with the BMW clutch is that, there is no easy way to have a smooth upshift unless you upshift at high rpms. For some reason BMW tranny doesn't like low-RPM upshifts. Downshifts are not a problem since you have enough time then to double-clutch to match the RPM. It seems to me that there is only two ways to have a smooth transition when upshifting:

1. Shift quickly at high RPMs > 4500
2. Shift slowly at low RPMs, double clutch to rev-match just as you would do when you are downshifting.

The second method is not practical since you lose speed quickly while doing so.

Just have to live with it I guess.

Originally Posted by mkodama

Rev matching is only needed on downshifting.

+1

Originally Posted by sprintman

All good drivers double declutch changing down. Get somebody to show you how and practise as much as possible. Great stuff when you get it right and your syncro's will love it.

uhhh.... no. the entire purpose of double clutching was for cars before they had synchros. you're synchros won't love it because they wont know the difference because they are there to the expressed purpose of eliminating the need for double clutching... but hey, keep on trucking.

^ truth.

But double clutching sure is fun ain't it!

I only do it when the trans is freezing in the morning. Double clutch up and downshifts till the fluid is warm. After that. I only double clutch (downshifts only) on trans with what feels like worn synchros.

When I was taught about rev-matching and double clutching I spent time practicing both. Soon, I stopped double clutching as it seemed to waste time.

Unless I am mistaken. For Down shifts...

Option 1 - rev matching - push clutch down, rev engine to desired rpm (with our cars, usually around 1k higher than current gear, but depends on gear and speed) and let clutch back up. This created much smoother down shifts that don't waste time wearing out clutch, tranny, synchros, etc. It also sounds cool. The person who taught me was telling me that it sounds like you are beating your car up, revving it all the time like that, but it is actually better for the car.

Option 2 - double clutching - similar to simply rev matching, except that you don't rev with the clutch down. Use the clutch to get out of gear, once in neutral, with clutch released, rev, then push clutch down and go into gear. This option doesn't sound better, and is harder to do quickly, although I guess it makes the driving experience more interactive.

My question - What benefits does double clutching have over simply rev matching?

On heel-toe. This is essential for downshifting while simultaneously braking through corners. Definitely needed for any type of track driving, although not needed for regular street driving and can be VERY difficult for people such as myself with size 13 feet. When I do try this, I use heel on gas pedal and toe on clutch. I have known others who did it the other way around.

I think this is a good post, and am surprised this isn't a more frequent topic. I am sure that many people on here, however much of a fanatic they may seem, are not up to speed on these topics.... including myself. I would love to hear more input.

My experience with the BMW clutch is that, there is no easy way to have a smooth upshift unless you upshift at high rpms.

Can someone confirm this?

My experience with the BMW clutch is that, there is no easy way to have a smooth upshift unless you upshift at high rpms.

Can someone confirm this?

I can confirm that first to second is very tough to make smooth... at any rpm.

Originally Posted by Len013091

Rev matching as in letting the clutch out quickly once the rpm hits exactly the right spot? Yea I do that. It's what you're supposed to do. The gas comes on right when the clutch engages, if you don't do that, the car will jerk as the engine is slowing down while the car is still moving foreward. If by revmatching you mean slipping the clutch a bit to get it smooth, try to avoid that on both upshifts and downshifts.

Originally Posted by pMak26

Do this:
http://videos.streetfire.net/video/H...hing_57431.htm

dayum! That is awesome!!

Originally Posted by RSteckhahn

When I was taught about rev-matching and double clutching I spent time practicing both. Soon, I stopped double clutching as it seemed to waste time.

Unless I am mistaken. For Down shifts...

Option 1 - rev matching - push clutch down, rev engine to desired rpm (with our cars, usually around 1k higher than current gear, but depends on gear and speed) and let clutch back up. This created much smoother down shifts that don't waste time wearing out clutch, tranny, synchros, etc. It also sounds cool. The person who taught me was telling me that it sounds like you are beating your car up, revving it all the time like that, but it is actually better for the car.

Option 2 - double clutching - similar to simply rev matching, except that you don't rev with the clutch down. Use the clutch to get out of gear, once in neutral, with clutch released, rev, then push clutch down and go into gear. This option doesn't sound better, and is harder to do quickly, although I guess it makes the driving experience more interactive.

My question - What benefits does double clutching have over simply rev matching?

On heel-toe. This is essential for downshifting while simultaneously braking through corners. Definitely needed for any type of track driving, although not needed for regular street driving and can be VERY difficult for people such as myself with size 13 feet. When I do try this, I use heel on gas pedal and toe on clutch. I have known others who did it the other way around.

I think this is a good post, and am surprised this isn't a more frequent topic. I am sure that many people on here, however much of a fanatic they may seem, are not up to speed on these topics.... including myself. I would love to hear more input.