Why is rev matching an on/off situation
07-30-2013, 10:53 PM
#82
Rev matching yourself and heel toeing is awesome.. when you know how to do it and your shifts up and down are as smooth as an automatic whatever the speed you are at is an accomplishment that you continue to strive to do as perfectly as you can...every time you get in a manual car. It takes cerebral effort and it makes you smarter.
I have driven passengers in my car who drive manuals say to me wow your shifts are so smooth! I didnt even feel that you were shifting, how did you do that? And when I tell them what im doing they respect you as a driver..
So you can than say, yes I can drive now..I can shift like a pro.. Having a machine do it for you is good just to help you learn how to do it for yourself.. and if you are tired and are stuck in tons of traffic.
But I have driven Ferraris with the paddle shifters and I must say they are awesome too.. But the manual just makes it more fun. But if I was on a track where you have to do lots of multiple downshifts at speed I would want a ferrari type paddle shift tranny because its safer
and quicker.. You just cant match it in a manual car. Its shifts ridiculously fast..
I have driven passengers in my car who drive manuals say to me wow your shifts are so smooth! I didnt even feel that you were shifting, how did you do that? And when I tell them what im doing they respect you as a driver..
So you can than say, yes I can drive now..I can shift like a pro.. Having a machine do it for you is good just to help you learn how to do it for yourself.. and if you are tired and are stuck in tons of traffic.
But I have driven Ferraris with the paddle shifters and I must say they are awesome too.. But the manual just makes it more fun. But if I was on a track where you have to do lots of multiple downshifts at speed I would want a ferrari type paddle shift tranny because its safer
and quicker.. You just cant match it in a manual car. Its shifts ridiculously fast..
07-31-2013, 01:33 AM
#83
Heel & Toe
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I have rev matching in a 991S. It is absolutely seamless and not only matches down shifts but assists in up shifts as well as long lazy slow shifts a slower speeds. I think the C7 is going to be a winner and look forward to driving it.
07-31-2013, 01:43 AM
#85
Racer
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i just hope the paddles are not "intrusive" behind the wheel.. some brand paddles seem like an afterthought and are in the way or too close to the stalks or wheel... whereas other brands think about it in design and move the stalks back a little bit giving them more room..
i assume the paddles are identical for auto and manual just with different decal applied?
i assume the paddles are identical for auto and manual just with different decal applied?
07-31-2013, 11:15 AM
#86
Drifting
I started thinking about the subject again on my way home from work just now.
It's been stated on here that rev-matching doesn't do anything for the synchros. Again, I'm going to say that doesn't seem correct. While, in theory, it does seem correct, it would assume there's no dragging or friction from the flywheel to the input shaft.
If the theory was correct, then you wouldn't have to rev up at all to get the shifter into a lower gear while at speed. But the reality is that the lower the RPM is on the engine, and the lower the gear you want to get into from a higher gear, the harder it is to get the shifter into the gate.
When you rev-match, the shifter goes into the gate much smoother and with near-zero effort. But the clutch is fully pressed in. Why is that? The clutch MUST be dragging, right?
Not trying to sound condescending at all. Just trying to point out a link between the engine RPM and shifting while the clutch is fully disengaged.
It's been stated on here that rev-matching doesn't do anything for the synchros. Again, I'm going to say that doesn't seem correct. While, in theory, it does seem correct, it would assume there's no dragging or friction from the flywheel to the input shaft.
If the theory was correct, then you wouldn't have to rev up at all to get the shifter into a lower gear while at speed. But the reality is that the lower the RPM is on the engine, and the lower the gear you want to get into from a higher gear, the harder it is to get the shifter into the gate.
When you rev-match, the shifter goes into the gate much smoother and with near-zero effort. But the clutch is fully pressed in. Why is that? The clutch MUST be dragging, right?
Not trying to sound condescending at all. Just trying to point out a link between the engine RPM and shifting while the clutch is fully disengaged.
If the clutch is dragging, then what you're saying is right.
That said, the synchros do have to work harder when you skip a gear on a downshift. On a downshift, parasitic losses are trying to slow down the input shaft, and the synchros have to work against this. When you skip a gear, the synchros have to overcome a higher relative rotational speed.
I usually always heel-toe even on the street, but for the hell of it this morning I did a series of 4-2 downshifts both ways; rev-match and no rev-match. I could engage 2nd from 4th with no big issues without doing a rev match, and the feel was similar to when I rev matched. It is noticeably a little harder than going from 4-3, which I always attributed to the synchros working a little harder on the 4-2..
.
07-31-2013, 11:44 AM
#87
07-31-2013, 10:40 PM
#89
Le Mans Master
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If the clutch is dragging, then what you're saying is right.
That said, the synchros do have to work harder when you skip a gear on a downshift. On a downshift, parasitic losses are trying to slow down the input shaft, and the synchros have to work against this. When you skip a gear, the synchros have to overcome a higher relative rotational speed.
I usually always heel-toe even on the street, but for the hell of it this morning I did a series of 4-2 downshifts both ways; rev-match and no rev-match. I could engage 2nd from 4th with no big issues without doing a rev match, and the feel was similar to when I rev matched. It is noticeably a little harder than going from 4-3, which I always attributed to the synchros working a little harder on the 4-2..
.
That said, the synchros do have to work harder when you skip a gear on a downshift. On a downshift, parasitic losses are trying to slow down the input shaft, and the synchros have to work against this. When you skip a gear, the synchros have to overcome a higher relative rotational speed.
I usually always heel-toe even on the street, but for the hell of it this morning I did a series of 4-2 downshifts both ways; rev-match and no rev-match. I could engage 2nd from 4th with no big issues without doing a rev match, and the feel was similar to when I rev matched. It is noticeably a little harder than going from 4-3, which I always attributed to the synchros working a little harder on the 4-2..
.
Did you happen to do some rev-matched 4-2 and non-rev-matched 4-2 shifts? I've noticed that every single time, it's much easier to get into 2nd from 4th if I rev-match. Every single time.
08-01-2013, 10:28 AM
#90
Drifting
I also have a fairly new LS7 clutch and slave cylinder with a bleed, and pretty fresh synthetic tranny fluid. When my slave cylinder was on its way out last year, I did notice some clutch drag and some rough downshifting. Have you ever changed your clutch fluid?
.
Last edited by RedLS6; 08-01-2013 at 10:33 AM.
08-02-2013, 07:22 AM
#91
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Nope. And on the original clutch and slave. There wasn't many miles on the car. It's too late now, though. The Z06 is sold.
Clutch drag is the only thing that makes sense. But this is something I've seen in at least a dozen manual cars I've driven.
So in the case that I'm right and there's clutch drag, the rev-matching would indeed help save the synchros.
Clutch drag is the only thing that makes sense. But this is something I've seen in at least a dozen manual cars I've driven.
So in the case that I'm right and there's clutch drag, the rev-matching would indeed help save the synchros.
08-02-2013, 10:55 AM
#92
I've read elsewhere that to prolong the life of your synchros you should not be skipping gears on shifts - if you are going from 4 to 2, it's clutch pedal in, down to 3, then down to 2, clutch out. This minimizes the speed differences the synchros have to deal with and so reduces wear.