[F87 2018]

So a few days ago the dude in front brake checked me and I didn't have the time to react, but unlike what I usually do when I have to stop quick (clutch in downshift clutch out in each gear), I just had the clutch in and went from 5th to 2nd without letting the clutch out in between. It happened really quickly, like within a second, and the car rev matched three times, and when I let the clutch out, everything felt fine. I've been doing this ever since. Is it bad to rev match super quick consecutively? If not this is one fast way to downshift...

[chris719]

I am a bit confused. Do you think you have to shift sequentially in a manual transmission? You don't, you can shift from 6th to 2nd if you wanted, for example, as long as aren't going to blow up the engine from mechanical overrev. I'm also confused on what 3 rev matches means, the car should rev match once before you go into 2nd unless you got close to other gates and it falsely blipped the throttle I suppose.

[ScreamingChicken]

Question not super clear but I skip gears all the time when coming down from highway speed to a stop, usually skipping 3rd going into 2nd bc I might not have to come to a complete stop. I also end up skipping 5th while accelerating to highway speeds bc I find the 500 rpm difference between 5th and 6th to be ridiculous. If you moved the shift lever into each gear gate, it would have rev matched each gear even if you didn't release the clutch pedal. Even if you went from 5th to 2nd and didn't enter any other gates, if you moved close to any of the gates of the other gears it would rev match. This is all normal and ok unless you money shifted passed redline.

[F87_LCI]

Def skip 5th almost of the time on the way up. On the way down, depending on rpm will skip 5th or 4th (when in 6th or 5th respectively) on hwy and need to pass someone..I do find that occasionally the rev match doesn't work going from 3rd to 2nd....which is annoying because there doesn't seem to be a specific set of circumstances that I can replicate to make it happen...it's just random. Anyone else have this issue with the rev match?

[F87 2018]

Originally Posted by ScreamingChicken

Question not super clear but I skip gears all the time when coming down from highway speed to a stop, usually skipping 3rd going into 2nd bc I might not have to come to a complete stop. I also end up skipping 5th while accelerating to highway speeds bc I find the 500 rpm difference between 5th and 6th to be ridiculous. If you moved the shift lever into each gear gate, it would have rev matched each gear even if you didn't release the clutch pedal. Even if you went from 5th to 2nd and didn't enter any other gates, if you moved close to any of the gates of the other gears it would rev match. This is all normal and ok unless you money shifted passed redline.

Yea that's what happened. I guess it's like skipping gears really.

[F87 2018]

Originally Posted by F87_LCI

Def skip 5th almost of the time on the way up. On the way down, depending on rpm will skip 5th or 4th (when in 6th or 5th respectively) on hwy and need to pass someone..I do find that occasionally the rev match doesn't work going from 3rd to 2nd....which is annoying because there doesn't seem to be a specific set of circumstances that I can replicate to make it happen...it's just random. Anyone else have this issue with the rev match?

I get this sometimes. Also from 2nd to 1st... even though I don't usually go down to 1st, the rev match almost never happens if I do.

[twin fed]

I skip gears all the time. Both up and down. Perfectly safe if done correctly.

[alscks0414]

Originally Posted by F87_LCI

Def skip 5th almost of the time on the way up. On the way down, depending on rpm will skip 5th or 4th (when in 6th or 5th respectively) on hwy and need to pass someone..I do find that occasionally the rev match doesn't work going from 3rd to 2nd....which is annoying because there doesn't seem to be a specific set of circumstances that I can replicate to make it happen...it's just random. Anyone else have this issue with the rev match?

I do pretty much the same. But never felt that I have missed rev matching from 3rd to 2nd. Always works

[ZPrime]

Originally Posted by F87_LCI

Def skip 5th almost of the time on the way up. On the way down, depending on rpm will skip 5th or 4th (when in 6th or 5th respectively) on hwy and need to pass someone..I do find that occasionally the rev match doesn't work going from 3rd to 2nd....which is annoying because there doesn't seem to be a specific set of circumstances that I can replicate to make it happen...it's just random. Anyone else have this issue with the rev match?

I often go from 6th to 3rd, and when I pop the shifter out of 6th I allow it to self-center, and it tends to blip once and hold revs, but not at the right RPM for 3rd. Then as I push it into the gate for 3rd, it blips higher and holds and I de-clutch and it's fine.

So yeah, it seems like sometimes it gets a little confused about where it should be revmatching to, and I've occasionally gotten two different revmatches from this.

While we're all talking about downshifting here - how does everybody let off the clutch during an aggressive downshift (i.e. preparing to pass on the highway, or while braking for a lower speed turn that you want to power out of)? I've found that if I try to let the clutch up slowly / in a controlled fashion, the car often gets a bit unsettled.

It seems like quickly coming off the clutch pedal (sidestepping) immediately after the car blips and I'm fully slotted to the lower gear is a better practice - does this make any sense to anybody else?

This should theoretically have the least amount of clutch wear, since the flywheel is being held at the correct RPM and the clutch disc is not being asked to slip much (it's being slammed shut quickly by the pressure plate). OTOH, the abrupt clutch engagement might then throw more lash into the gearbox and driveshaft?

I'm trying to figure out which is most friendly to the driveline. I suppose clutch wear is better than abuse to the gears or shaft, since (theoretically) it's easier and cheaper to replace the clutch than the other parts...

[Nezil]

Originally Posted by ZPrime

While we're all talking about downshifting here - how does everybody let off the clutch during an aggressive downshift (i.e. preparing to pass on the highway, or while braking for a lower speed turn that you want to power out of)? I've found that if I try to let the clutch up slowly / in a controlled fashion, the car often gets a bit unsettled.

It seems like quickly coming off the clutch pedal (sidestepping) immediately after the car blips and I'm fully slotted to the lower gear is a better practice - does this make any sense to anybody else?

I like the rev-match in general, but it does force you to drive / shift more aggressively.

I'm not old (39), but somewhat old-school I guess in that I was always taught (back in England, by the way) to double clutch, because it matches the speed of the engine, and the gearbox before you shift. This process involves rev-matching higher than exactly what you need, because you clutch in, shift to neutral, clutch out, rev, clutch in, shift. The extra time needed to do this has you rev slightly higher so that the revs drop to the right point as you shift into the lower gear.

To be honest, double clutching is second nature for me, but not nearly as fast as single rev-matching, and I actually find that harder to do.

So, until I had my M2, for normal, non-aggressive driving, I'd shift down by slowly letting out the clutch as you describe, slightly slipping it I guess, but this results in a smooth down shift. If I was driving harder, probably with a larger difference between revs as I downshift, I'd double clutch, which is quicker, and has much less clutch slip, but it's agressive.

In the M2, I find myself naturally tending to slip the clutch when I'm not driving aggressively, but that results in a jolt because the rev match stops as soon as you are in gear, the revs drop quickly and the drive train clonks. If you clutch out quickly, it's much smoother, but my muscle memory doesn't do that all of the time - old habits die hard!

I guess that's what you mean?

[F87 2018]

Originally Posted by ZPrime

I often go from 6th to 3rd, and when I pop the shifter out of 6th I allow it to self-center, and it tends to blip once and hold revs, but not at the right RPM for 3rd. Then as I push it into the gate for 3rd, it blips higher and holds and I de-clutch and it's fine.

So yeah, it seems like sometimes it gets a little confused about where it should be revmatching to, and I've occasionally gotten two different revmatches from this.

While we're all talking about downshifting here - how does everybody let off the clutch during an aggressive downshift (i.e. preparing to pass on the highway, or while braking for a lower speed turn that you want to power out of)? I've found that if I try to let the clutch up slowly / in a controlled fashion, the car often gets a bit unsettled.

It seems like quickly coming off the clutch pedal (sidestepping) immediately after the car blips and I'm fully slotted to the lower gear is a better practice - does this make any sense to anybody else?

This should theoretically have the least amount of clutch wear, since the flywheel is being held at the correct RPM and the clutch disc is not being asked to slip much (it's being slammed shut quickly by the pressure plate). OTOH, the abrupt clutch engagement might then throw more lash into the gearbox and driveshaft?

I'm trying to figure out which is most friendly to the driveline. I suppose clutch wear is better than abuse to the gears or shaft, since (theoretically) it's easier and cheaper to replace the clutch than the other parts...

I noticed that in sport+ if I let it out slowly the car really doesn't like it, but in comfort the rev match seems to be a lot slower, so slowly coming off the clutch works better in comfort. However in Sport mode I haven't figure out a way to let off the clutch, it sometimes jerks if I come off too quickly, or too slowly. Do you notice the same in Sport?

[cookiesowns]

no issues here. In comfort I will get more jolts due to relying on the slower rev match... now i've built muscle memory to revmatch in comfort/MDM which is what I drive in 65% of the time.

In sport+ because the rev matches happen so quickly I've built muscle memory to let the car do its thing, or use my foot to add to it if I need to. I also revmatch my 1st gear starts instead of letting clutch slip, or slip 2nd above 2-3mph and under 8mph.

My biggest gripe is revmatch doesn't allow revs to fall quick enough if you clutch in, move the shifter to gate while on the clutch & brake, so if you let go of the clutch too quick the revmatch isn't proper.

Driving in comfort and doing rev matching my own prevents me from being lazy

[eeyang92]

Originally Posted by F87_LCI

Def skip 5th almost of the time on the way up. On the way down, depending on rpm will skip 5th or 4th (when in 6th or 5th respectively) on hwy and need to pass someone..I do find that occasionally the rev match doesn't work going from 3rd to 2nd....which is annoying because there doesn't seem to be a specific set of circumstances that I can replicate to make it happen...it's just random. Anyone else have this issue with the rev match?

Originally Posted by F87 2018

I get this sometimes. Also from 2nd to 1st... even though I don't usually go down to 1st, the rev match almost never happens if I do.

The car will not rev match if you let the revs fall below ~1k RPM.

On the topic of skipping gears, be aware that since you aren't double clutching, the bigger the gap in RPMs the more wear you'll put on your synchros.

Generally if I want to pass on the highway while cruising @ 80 mph I'll drop from 6th -> 4th, and very rarely 6th -> 3rd (if I want to pass really quickly).

[boostm3]

Originally Posted by F87 2018

So a few days ago the dude in front brake checked me and I didn't have the time to react, but unlike what I usually do when I have to stop quick (clutch in downshift clutch out in each gear), I just had the clutch in and went from 5th to 2nd without letting the clutch out in between. It happened really quickly, like within a second, and the car rev matched three times, and when I let the clutch out, everything felt fine. I've been doing this ever since. Is it bad to rev match super quick consecutively? If not this is one fast way to downshift...

IF you have to stop extra quickly, why downshift at all? Just clutch in and hit the brakes hard.