[danonymous]

Hi folks, I am hoping those who know more about cars than I can answer two questions for me regarding an M2C with MT:

1. For optimum acceleration, at what RPM should one go from 1st to 2nd gear? I have heard many people say they "short shift 1>>2" or "get out of first as soon as possible". A science based answer would be preferred.

2. IF one was accelerating quickly, got to 6500rpm in 2nd, then pushed in the clutch pedal and put the shifter into 1st gear (instead of 3rd) what would happen before they let out the clutch pedal? Would rev-matching computer detect the error and shut down the motor? Or would it damage/destroy something? Would it be different if they did it slowly (thus having time to see the reaction from rev-match) vs slamming it into 1st? This nightmare scenario is why I have never loaned out the car to anyone.

Thank you.

[SEAT TIME RULES]

Originally Posted by danonymous

Hi folks, I am hoping those who know more about cars than I can answer two questions for me regarding an M2C with MT:

1. For optimum acceleration, at what RPM should one go from 1st to 2nd gear? I have heard many people say they "short shift 1>>2" or "get out of first as soon as possible". A science based answer would be preferred.

2. IF one was accelerating quickly, got to 6500rpm in 2nd, then pushed in the clutch pedal and put the shifter into 1st gear (instead of 3rd) what would happen before they let out the clutch pedal? Would rev-matching computer detect the error and shut down the motor? Or would it damage/destroy something? This nightmare scenario is why I have never loaned out the car to anyone.

Thank you.

If you miss shift your car its called a "Money Shift" Exhaust valves will hit the pistons and your f-ked...

As for shifting from 1-2 I don't care. Your traction limited as it is...

I don't do light to light crap, and 1-2 is just to get me out on the road course surface..

[DanG]

When I had a 6 speed, I would shift from 1st to 2nd at 4,000 rpm during normal street driving.

[BigKutta]

1) really depends on you and what you prefer, but I'd personally exit by 4k
2) "what would happen before they let out the clutch pedal?" Nothing. But once the clutch is released, money shift at that rpm most likely

[(K)]

1st to 2nd I usually shift around 3k-4k. That way you're building enough momentum for the 2->3 shift and also putting some distance between you and the car behind you to compensate for that delay in gear change.

If you managed to get into 1st gear but not release the clutch, I think the computer would know not to attempt to rev match that. Don't quote me on that though. If their shifting technique is proper then 2nd to 1st is virtually eliminated. The return spring guides into neutral and you're just applying pressure (not FORCE) with your palm to 3rd gear. If that makes sense.

[keylime503]

#2 isn't possible. Seriously, try it. The 6MT box is these cars locks out 1st gear after a certain road speed. You literally cannot shift into 1st gear if you're at 6500 rpm in 2nd gear the shifter won't go into the slot.

[redgs4]

I'm in the 3K-4K camp as well for everyday driving - these cars have so much torque I just get into 2nd ASAP.

Technique and muscle memory will help prevent the money shift.

UCC Shifting Technique Tutorial

.

[akkando]

In theory if you moved into first gear with revmatch on but don't let the clutch out the revs should shoot up to 7600 rpm which would be one clue that you missed 3rd. However I noticed rev match generally didn't work if I pushed the clutch in and coasted for a while, then selected a gear after waiting for a bit. So I suppose if you were rolling at 70 with the clutch in for several seconds then somehow got it into first it might not even attempt a rev match.

The bigger danger on the street is probably top of 3rd to 2nd instead of 4th.

[Rumbloki]

I would wager that 99% of money shifts occur when downshifting. Your going from 6 to 4 and in your haste you grab 2.

There is no reason to go from1 to 2 ASAP. If moving quickly, run it out so you will still be in the power band when you upshift. As to cruising around, you will find on your own what is comfortable to you. It will likely be 2500 to 3500. A little higher if you want more pops and bangs.

[Moflow]

I feel like I heard somewhere that there’s a “money shift alarm sound” that the car will make if you’re about to money shift. I think it’s usually 3-2 instead of 3-4 that’s most common, but honestly money shifts are hard to do if you’re not banging gears and trying to drive like an asshole. I’ve accidentally gone 4-3 instead of 4-5, but I wasn’t trying to shift at redline or anything so the car just rev matched up to about 6500 rpm (though I caught it quickly enough to not let out the clutch anyway.)

Don’t treat it like a drag car, have mechanical sympathy while you drive and it really shouldn’t be a thing you need to worry about. Plus your drivetrain will wear our way slower. I’m not saying don’t drive it hard, I shift at redline from time to time, but banging gears by shifting super fast and dropping the clutch is just kinda mean to the car.

Anecdotally, some friends and I own a beater race car for the 24 hours of lemons. I have a camera setup in it so I get to see everyone’s driving style. I double clutch and rev match my downshifts and generally shift with mechanical sympathy, but not all of my co-owners are so gentle. Guess what? They don’t actually get the car around the track any faster than I do.

[Rumbloki]

Originally Posted by Moflow

Don’t treat it like a drag car, have mechanical sympathy while you drive and it really shouldn’t be a thing you need to worry about. Plus your drivetrain will wear our way slower. I’m not saying don’t drive it hard, I shift at redline from time to time, but banging gears by shifting super fast and dropping the clutch is just kinda mean to the car.

Anecdotally, some friends and I own a beater race car for the 24 hours of lemons. I have a camera setup in it so I get to see everyone’s driving style. I double clutch and rev match my downshifts and generally shift with mechanical sympathy, but not all of my co-owners are so gentle. Guess what? They don’t actually get the car around the track any faster than I do.

Preach.

[Gizmo 335i]

Posters above are correct about the money shift. It can and does happen. With respect to 1-2, I found BMWs to be much smoother when I shift almost immediately (which is no fun) or at ~3,200 RPMs or better. In between is jerky.

[annabellapizza]

agree, for most BMWs, the first gear is just to get rolling, best to shift as soon as you can without letting the revs drop

[jkoral]

Originally Posted by SEAT TIME RULES

If you miss shift your car its called a "Money Shift" Exhaust valves will hit the pistons and your f-ked...

Originally Posted by Rumbloki

I would wager that 99% of money shifts occur when downshifting.

I don't believe it's 99%, we even have video of an M2C Money Shift accelerating 4th to 3rd instead of 5th:
https://f87.bimmerpost.com/forums/sh....php?t=1662729

[Fenerbahce]

Not seeing many science based answers, so I'll give it a go...

1. As long as conditions are good and you're smooth in laying into the throttle (so you get weight transfer to the back), you should be able to go WOT in 1st just fine without losing traction. Unless you have traction issues, there is no reason to shift early (you'll just be leaving horsepower on the table). Peak power is from 5230-7000 rpm according to BMW, so you shouldn't shift before 7000 and you may want to carry it even a little beyond so as not to land too low in the power band in second. Where that optimal point is depends on how quickly the torque falls on its face as it approaches 7600. I think it's safe to say shifting somewhere between 7000 and 7600 will get you maximum acceleration. This assumes BMW does no funny business limiting torque in first gear, etc.

2. This has been asked before but I don't think I've ever seen anyone conclusively say what happens when you shift into a gear that will carry your revs well beyond redline but don't release the clutch. Does the engine rev match to redline, but nothing more? Does it not rev match at all? Does it over rev itself (hopefully not!)? This is like the question of how many licks it takes to get to the center of a tootsie pop - we may never know.