6MT: Ugh downshifted without rev matching

[F80Moe]

Originally Posted by AlterZgo

Totally agree. For me, as well, it is extremely hard to rev match smoothly when braking moderately or gently during normal driving.

Very true

I do flick sport + for fun and when I heel/toe my driving is very far away from smooth

[gatorfast]

Originally Posted by captainaudio

To me an MT that auto rev matches is a "Semi Manual Transmission".

I don't like auto rev matching on an MT but I understand that some people do. If it could be turned on an off in all modes I would not have any issue with it.

Ehh I dont think the computer simply blipping the throttle somehow makes it less of a manual process. You still need to manually clutch in and select your gear. Plus, there are plenty of terrible MT drivers out there that dont rev match anyway any simply slip the clutch to move to a lower gear.

But agree an on/off switch in all modes is preferable and best overall solution.

[clutchdj]

Keep practicing

[Rambler]

This is probably how 99% of those with manuals shift on a normal basis (at least when manuals were more prevalent and auto rev matching wasn't a feature), often getting over 100k miles on an original clutch. I'd say you're fine.

[FatRear08]

My daily is a 2007 Civic 5MT. 239k highway miles and on the original clutch. I can count on both hands the amount of times I rev matched. As long as you’re not banging the hell out of it, it’s fine.

[Aaaaaaaaa]

Originally Posted by FatRear08

My daily is a 2007 Civic 5MT. 239k highway miles and on the original clutch. I can count on both hands the amount of times I rev matched. As long as you’re not banging the hell out of it, it’s fine.

Awesome. But I assume you don't dump the clutch on downshifts like I did?

[FatRear08]

Sometimes on a quick downshift I’ll dump it to pass or something, but as long as you’re not constantly doing that, they’ll all be fine. Esp our F8x’s(my F80 is a 6MT) as I’m sure they’re more robust than my Honda’s trans. As many have said before, our cars can take a beating, not that you should, but if they can withstand track days etc, less than perfect shifts here and there I don’t think will turn the trans or drivetrain to crap.

[ImGoingPlaces]

what is a money shift ?

[Aaaaaaaaa]

Originally Posted by ImGoingPlaces

what is a money shift ?

You over rev the engine and destroy it. For example on the freeway accelerating full WOT near redline in 5th and somehow you inexplicably shift into 2nd. Nothing to stop the engine from revving way past redline and explodes.

[FatRear08]

Downshifting into the wrong gear and redlining the f@ck out of the engine usually costing money to fix what you broke

[Absurdium]

This is like, a 0.5 on that scale if that. I would not worry about it at all. . How you think people launch MT cars?

[moonluv810]

Don't get me wrong here... all these comments about not being able to execute heel toe downshift rev matching perfectly kind of confuse me.
Isn't this the reason we all still drive stick shift cars? We want more driver's engagements? Although manual cars are slower than DCTs, we want that connection?

I for one am not a race car driver. I do 3-4 track days a year and am far from being perfect in executing heel toe downshifts in that tight corner, 120-40mph braking, cars ahead and behind you, and with sweats dripping off your forehead (you get the idea). But that what makes me continue driving stick shift cars. I rely on myself in controlling the car and when all the planets are in alignment and you execute that perfect shift, oh what a joy!

#savestickshift

[gatorfast]

Originally Posted by FatRear08

My daily is a 2007 Civic 5MT. 239k highway miles and on the original clutch. I can count on both hands the amount of times I rev matched. As long as you’re not banging the hell out of it, it’s fine.

Why wouldn't you rev match Must make for one hell of a jerky ride.

[silvergray545]

Originally Posted by pheerlx

You over rev the engine and destroy it. For example on the freeway accelerating full WOT near redline in 5th and somehow you inexplicably shift into 2nd. Nothing to stop the engine from revving way past redline and explodes.

Very dramatic. I like it.

Friend of mine money shifted his E36 M3 not too long ago. He was at redline in 3rd and accidentally caught 2nd. Wound up bending a bunch of valves. The pistons had some knicks from kissing the valves but they were still fine, structurally. He had a machine shop clean up the head and replace the valves. Slapped everything back together and it fired right up.

[FatRear08]

Originally Posted by gatorfast

Why wouldn't you rev match Must make for one hell of a jerky ride.

I just ease it out and it’s pretty smooth actually. In my F80 not so much, where I’ll rev match it when in sport +

[captainaudio]

Originally Posted by moonluv810

Don't get me wrong here... all these comments about not being able to execute heel toe downshift rev matching perfectly kind of confuse me.
Isn't this the reason we all still drive stick shift cars? We want more driver's engagements? Although manual cars are slower than DCTs, we want that connection?

I for one am not a race car driver. I do 3-4 track days a year and am far from being perfect in executing heel toe downshifts in that tight corner, 120-40mph braking, cars ahead and behind you, and with sweats dripping off your forehead (you get the idea). But that what makes me continue driving stick shift cars. I rely on myself in controlling the car and when all the planets are in alignment and you execute that perfect shift, oh what a joy!

#savestickshift

I feel the same way. I find one of the most enjoyable things about driving a manual transmission is executing perfectly rev matched heel and toe down shifts.

Technically all down shifts should be rev matched. If they are not you are putting a strain and wear on the clutch and possibly upsetting the balance of the car. You can get away with it if you are well below the limits (grip) of the car but that does not mean it is a good practice.

[M-Pilot]

Originally Posted by gatorfast

Why wouldn't you rev match Must make for one hell of a jerky ride.

Not really unless he is dumping the clutch after each downshift. He must be releasing the clutch slowly to avoid the jerky downshift. In fact, many people who claim to be an expert in driving MT cars downshift this way and have no idea what rev matching or heel/toe downshifting is.

[FatRear08]

Originally Posted by cntzl

Not really unless he is dumping the clutch after each downshift. He must be releasing the clutch slowly to avoid the jerky downshift. In fact, many people who claim to be an expert in driving MT cars downshift this way and have no idea what rev matching or heel/toe downshifting is.

Yes, that’s what I said in my previous post. I ease it out as I feel no need to rev match in that car. The amount of miles I have on the clutch and car tell me I’m not performing anything wrong by doing that. On the other hand, I do and enjoy rev matching in the F80 when I am in sport plus.

[gatorfast]

Originally Posted by cntzl

Not really unless he is dumping the clutch after each downshift. He must be releasing the clutch slowly to avoid the jerky downshift. In fact, many people who claim to be an expert in driving MT cars downshift this way and have no idea what rev matching or heel/toe downshifting is.

Even if releasing slowly I don't see how it can't produce a jerky ride. The revs will immediately drop when you clutch in and then shoot back up no matter how slowly you release the clutch.

If you are a driver that doesn't understand rev matching then I get why you would do this as it's the only way to make the car move. But if you do understand how to rev match and still don't do it that just baffles me considering how easy it is to simply blip the throttle before changing gears and produce a smooth shift.

[FatRear08]

Originally Posted by gatorfast

Even if releasing slowly I don't see how it can't produce a jerky ride. The revs will immediately drop when you clutch in and then shoot back up no matter how slowly you release the clutch.

If you are a driver that doesn't understand rev matching then I get why you would do this as it's the only way to make the car move. But if you do understand how to rev match and still don't do it that just baffles me considering how easy it is to simply blip the throttle before changing gears and produce a smooth shift.

Don’t be baffled...it’s not worth it. Especially on Sunday. Maybe in 2007 Honda produced a magic clutch that makes for a non-jerky transition. Who knows...I do know that somehow the car appreciates the way I drive it or it wouldn’t have treated me this good for 11 years. If the car doesn’t need it, then I simply forgo the process. And honestly, I don’t need to tell you this, but the driving dynamics are light years apart. I flat out enjoy rev matching the M not just because it smooths it out, but because I hear my aftermarket exhaust and downpipes bark, letting me enjoy the money I spent back there.

[MaynardZed]

Less rotating mass in the smaller Civic engine and he's not driving at the limit. It's just commuter car, no need to rev match. Can just wait until he's slowed down before releasing the clutch.

With smaller drivetrains, you can get away just fine without rev matching. My dad races Formula Ford which has a 1.6L 4 cylinder engine. They don't rev match when they're racing. He's built an E36 to race against me, but is struggling with perfecting the heel-toe since he never learned it in the Swift.

An extreme example of smaller engines not needing rev match is motocross dirt bikes. They don't rev match, they just downshift. Hell, they don't even use the clutch most of the time.

[JMon]

Not rev matching isn't always an issue. Many cars have dual
Mass fly wheels that absorb a "little" bit of shock. I don't know about the BMW though. Someone may be able to comment on that aspect.
I find myself not rev matching most manual cars I drive on the street. But I alway find myself doing a proper rev match on the track.
The biggest risk usually isn't to your engine but rather to your traction.
Think about missing a match mid corner Could put you into a wall or another car.

I had forgotten to set the 1-2 lockout on a non sequential GT3 cup car once and did a 3->2 instead of a 3->4 shift and spun pretty good. Also tested > 12k on the engine. No issues though.