Perfectly smooth upshifts-trick with disengaging the clutch

[gregxxxnt]

Hello everyone,

I'd like to add a few words about performing perfectly smooth upshifts. I've found that a lot of people here focus on releasing the clutch and giving some gas. It's crucial for smooth upshifts. However, I think that proper clutch disengaging is important as well That's my technique, which I use in normal driving with moderate throttle input. It allows me to do perfectly smooth upshifts:
1) Begin pushing the clutch before releasing the gas pedal (This creates a very smooth transition instead of a typical jerk caused by the engine braking and the pause in the acceleration). Begin releasing the gas JUST AFTER the step 1.
2) While still pushing the clutch continue releasing the gas pedal.
3) When the clutch pedal reaches the floor level the gas should be fully released.
4) Here comes the rest of shifting (moving the stick, releasing the clutch and applying the gas).

What's your opinion about this technique? Do you use it?

[theholycow]

We don't discuss it much, but that's the only way to do it (unless your car has rev hang, in which case your car does it for you whether you want it or not). We should probably remember to mention it when people have trouble with jerky driving.

[Shadow]

Hello everyone,

I'd like to add a few words about performing perfectly smooth upshifts. I've found that a lot of people here focus on releasing the clutch and giving some gas. It's crucial for smooth upshifts. However, I think that proper clutch disengaging is important as well That's my technique, which I use in normal driving with moderate throttle input. It allows me to do perfectly smooth upshifts:
1) Begin pushing the clutch before releasing the gas pedal (This creates a very smooth transition instead of a typical jerk caused by the engine braking and the pause in the acceleration). Begin releasing the gas JUST AFTER the step 1.
2) While still pushing the clutch continue releasing the gas pedal.
3) When the clutch pedal reaches the floor level the gas should be fully released.
4) Here comes the rest of shifting (moving the stick, releasing the clutch and applying the gas).

What's your opinion about this technique? Do you use it?

I think most stick drivers understand that shifting involves overlapping motions. It's not something we do mechanically with one step performed completely before we go to the next step. As a new stick driver gets more experienced, the whole process of shifting sort of gels into a combination of movements that occurs together. If not, it would be pretty much impossible to drive a manual transmission car smoothly.

[tankinbeans]

I should start stabbing the clutch before releasing the gas. I've always been completely off the gas when stabbing the clutch and I get jerky. Something I hadn't really about until I read this.

[gregxxxnt]

@tankinbeans, just try it and and enjoy the great smoothness

Furthermore, I suspect that the ETC in my car is designed for the above described technique. The engine revs won't instantly jump up even if I purposely delay a bit the release of the gas pedal (of course I'm still speaking about the moderate throttle usage).

Previously I was driving a car with mechanical throttle linkage. It required much more precision with disengaging the clutch, as the throttle had an instant response with no delay, in contrast to DBW car systems.

[bk7794]

Sometimes I do this, lets say I am driving at 30% throttle. This is while I am accelerating. I sometimes will then ease up on the throttle to like 5 or 10% and then push the clutch in. I found myself getting into this habit and never really found any drawbacks to it. Unless you need to really move. In that case I just go WOT until I clutch in.

[Chiba]

Hmm.. let me intentionally try that out.

[daleadbull]

I'm not sure if this would work for cars with rev hang, I feel like it would only make the rpm hang worse.

[tankinbeans]

I'm not sure if this would work for cars with rev hang, I feel like it would only make the rpm hang worse.

Clifford already seems to blip the throttle a little upon letting off the gas. I've monitored my timing and it seems it offs definitely the car doing it because my foot is always off for a fraction of a second before the revs increase.

[RITmusic2k]

If you're going for smoothness over all else, then technically you want the clutch to disengage with a neutral load on the driveline. In other words, not applying so much throttle that the engine revs would rise upon disengaging the clutch, but also not so little throttle that the engine revs would drop when you disengage.

That means you'll still be giving it a little bit of gas in all scenarios except for when you happen to be disengaging at idle rpm (as might happen when you're coasting to a stop).

This moment of neutral load, however, doesn't have to last long. In practice, I find that I can back off heavy throttle and feel the point at which my car is no longer accelerating, and stab the clutch pedal down at that instant while backing the rest of the way off the gas pedal. If you hit that point correctly you can press the clutch pedal in as quickly as possible (in fact, you should probably always disengage the clutch as quickly as possible, but strive toward doing it in a no-load situation in order to maximize smoothness).

[theholycow]

^Along those lines, if you get good at knowing when you hit neutral throttle you can shift out of gear without touching the clutch pedal. Looking at it the other way, you can practice doing that to get good at knowing neutral throttle. I do it all the time. You don't necessarily need to give it any gas as long as your timing is perfect.

Note that you should still use the clutch pedal to shift out of neutral into the next gear (unless you are perfect at double clutching, in which case you aren't in this thread looking for advice, but even then it's hard to know for sure on a synchronized transmission).

[AHTOXA]

Fluidity of movement almost always means that a number of separate motions are overlapping to one degree or another. Most experienced drivers will subconsciously develop this overlap as they drive. Most drivers don't analyze it to understand it fully.

[gregxxxnt]

@RITmusic2k, great remarks, that's exactly the goal of the method described by mine

@theholycow, I've heard about the popping out of gear without the clutch. But I wonder if it makes (or increases) a risk of shifting into the next gear with partially disengaged clutch, which is bad for the car. To be sure, I must try it out, because I haven't done this so far.

@AHTOXA, yes, that's right. Before I began thinking about this topic my shifts were smooth as well. However, I'm a type of person with analytical mind. I also enjoy being more and more conscious about cars and driving techniques

[theholycow]

I wonder if it makes (or increases) a risk of shifting into the next gear with partially disengaged clutch, which is bad for the car. To be sure, I must try it out, because I haven't done this so far.

It is inherently slow, almost as slow as double-clutching an upshift. You shouldn't have any issue of shifting into the next gear with the clutch only partially disengaged. I sometimes do it on upshifts but I do it every time I shift to neutral to coast, that's when it's most useful.

[gregxxxnt]

You shouldn't have any issue of shifting into the next gear with the clutch only partially disengaged.

By saying "partially disengaged" I meant shifting when the clutch is slipping a bit, thus transmitting some power. It's possible to press the clutch not to the floor and fully stop the transmission of power due to the clutch deadzone. But I think it's safer to fully press the clutch pedal, because different cars have different catch points.