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Patent Reveals BMW 7 Speed Manual Transmission Design!

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Many of our members know that I love manual transmissions. Yes, DCT is faster and technically superior, but everytime BMW hints at a future with fewer manual offerings (due to low take rates), it makes me cringe.

For manual BMW fans, there may be hope yet! A knock against manual transmissions now is fuel consumption (compared to the latest autos). With 7, 8 or even 9 gears, automatic and automated transmissions have an efficiency advantage as the extra gears allow for more economical gear ratios (think of really long 7th and 8th gears to improve MPG figures). A manual transmission cannot match this as the spacing of the gears for the shifter become too close to each other. But, we've now discovered a patent filed by BMW last year which shows that the company is exploring a manual transmission with 7 or more gears which solves these issues. Porsche by the way, also recently released a 7 speed manual in the new 911 (991).

Here's what BMW's patent entails. BMW first describes a problem with adding more gears above the current six speeds: "an 8 speed manual transmission would need four shift gates for the 8 gears alone" - meaning that's more gears than a normal driver can safely or practically handle (think of the higher probability of a mechanical over-rev from having so many gears, for example). BMW's solution is: A manual gear shifter that only allows the driver to shift into proper gears.

How is this achieved? According to the design, the shift gates are surrounded by a magnetorheologic or electrorheologic fluid. Relying on various sensors, a computerized shifting module calculates which gears are proper and which gears are wrong to select, given the driving situation (e.g. system will not allow shifting to 5th gear at 10mph or -- way worse -- shifting to 1st gear at 100mph). To prevent an improper shift, a magnetic field or electric voltage is applied to change the viscosity of the fluid, which will physically block the engaging of certain gears. This process is illustrated in the first diagram below.

The patent mentions two specific ways of implementing this technology:

Traditional Manual Transmission (With Clutch Pedal)

The technology can be used on a traditional manual transmission with up to 8 gears. The driver rows his own gears as usual (and uses a clutch pedal), but the computerized shifting module described above allows the driver to shift into proper gears while blocking dangerous gears, thus avoiding mechanical over-revs (the "money shift") for a manual transmission with so many gears.

Shift by Wire (Without Clutch Pedal)

BMW also sees a potential second application for this technology in the form of shift by wire. Think of it as a manual transmission without a clutch pedal - a mix of the traditional manual gear shift lever with the automated SMG transmission. When a driver attempts to move the shifter into a gear, the system first calculates if it's a good idea to go into that gear. If it is not, the shift gate for that gear is blocked as described above. If however, the system deems the desired shift OK, the clutch is disengaged automatically, the desired gear engaged, and then (and only then) can the shifter be maneuvered into the particular shift gate by the driver. All this is performed in less than a second. Additionally, the engaged gear number will be illuminated on the shifter's shift pattern (diagram below).

Please keep in mind that patents can take years to see actual implementation, if ever. But, we're happy to have discovered that BMW still sees a potential future for the manual shifting experience, albeit possibly with more gears, better fuel efficiency, and maybe even sans clutch pedal. Bring it on, BMW!

BMW Patent Drawings

[Giannis]

So, the actual gear has no mechanical connection to the gears themselves, just like Porsche's 7sp. manual. The lag could be an issue, but for me, the biggest issue is the loss of the feel of how the gears connect.

On a different page and completely understanding the idea of a fluid of some certain rheologic properties, my question is where would the limit be. Would a 5th to 2nd downshift be possible or for reasons of pure excitement, will the blocking of the (in this case) rear wheels due to an "improper" downshift, still be possible?

[MDyDinanM]

well it's about time.

I was wondering what car company would do this - glad it's BMW

[Karazy]

Great to see hope for us purists. I simply enjoy manually shifting to much. It's a connection I feel is lost on an auto.

[SomeRandomer123]

Sounds good! Things to go wrong? Many probably but I have one:
Short circuit electrifies the gear stick and leaves the driver paralysed into which he will plough his car into a field and knock some sheep and cows over.

So is 7th the only overdrive gear or is 6th still an overdrive?
Like 7th and 8th are overdrive gears on the 8AT

[3PedalMINI]

Originally Posted by Ka razy

Great to see hope for us purists. I simply enjoy manually shifting to much. It's a connection I feel is lost on an auto.

+1 im really excited to see that BMW still has an interest in investing in manual trannys. Looks like ill be a BMW customer for ever as other premium manufactuers are going away from manual. IE audi

Thanks BMW!

[Giannis]

Originally Posted by SomeRandomer123

Sounds good! Things to go wrong? Many probably but I have one:
Short circuit electrifies the gear stick and leaves the driver paralysed into which he will plough his car into a field and knock some sheep and cows over.

Of course, since electronics are involved, many things could go wrong, but I am of the opinion that a manually operated clutch is one of the most important safety features of a car, meaning that if the gearbox, the engine or electronics fail for some reason, you can still cut power to the wheels and stop safely.

[gary88]

Neat

[DrivenByE30]

It might not be an automatic, but it still not a true manual...
(can you dump the clutch?) ...

Well, i can see it is steps closer to simulate the true manual.

And at least, This system will make it much easier/practical for people to drive a "manual"! And it's Fool Proof !

.... as long as you can still dump the clutch... i would be happy.

and what about the clutch point ?? will we still feel it?? i have a feeling no... because no more mechanical link if all is by wire...
The clutch point is another important aspect of the manual!

This is similar to the electrical steering... one more ties to the road being disconnected...

Can't wait to see what BMW comes up... if they can perfectly simulate the manual without any compromise... then i will be sold!

[PaneristiDriver]

So basically they are coming out with something that Porsche has already done and perfected.
I guess it similar to the fact that Porsche created the dual clutch transmission and BMW has been playing catch up to it too (being the best on the market).
It's a good idea since this will keep the MT around but they arent breaking any ground here that someone hasnt already.

[GOLFFRR]

sweet

[cityazndan]

What's ironic is that I actually work for the PTO haha.

[Rolitto]

Thanks but give me DCT 7-speed anyday. Although I'm a good driver with a lot of experience in drifting, etc... but manual has been burried in my book.

[DDS2015]

It sounds complicated. I would wonder about the longevity of the system, and how exactly they'd implement something like this. They could use a similar design to Audi with their electromagnetic shocks, but I wouldn't want tiny iron filings in my transmission. Unless they had a separate compartment just for shifter fluid around the gates of it. Thats the only way I see this working. That being said, I'm no engineer and I'm curious to see what they come up with as I love playing with my stick

[Neegra]

Great that it is a consideration! At least not like MB wiped out all their Manual transmissions except for the C230?

I really dislike the clutch by wire idea though. As someone else mentioned, it will be like the feeling lost in the electrical steering systems. What I enjoy about a manual is the mechanical feel to it, the car control potential ('potential' because of some drivers haha), and the FUN.

Originally Posted by Ka razy

Great to see hope for us purists. I simply enjoy manually shifting to much. It's a connection I feel is lost on an auto.

That statement seems contradictory to me. Clutch by wire, sensors up the wazoo, 'magnetorheologic or electrorheologic fluid', and who knows what else will only lead to a loss in connection and separation from a 'pure' manual transmission. If anything, it is the opposite of a purist approach to me.

(not directed at anyone in particular)
If you don't want a clutch, that's why they have automatic. If you want to just 'shift' get an SMG...or any auto with the little paddles.

[jonerik26]

wow thats gonna be cool

[Jblack4083]

Why does everyone seem to think its not a "Pure manual" transmission. Everything seems exactly the same as the 6MT with the exception of it having a feature to prevent shifting into the improper gear.

The second option he writes about which is the clutchless manual is the one that everyone should be worried about?

Originally Posted by DrivenByE30

It might not be an automatic, but it still not a true manual...
(can you dump the clutch?) ...

Well, i can see it is steps closer to simulate the true manual.

And at least, This system will make it much easier/practical for people to drive a "manual"! And it's Fool Proof !

.... as long as you can still dump the clutch... i would be happy.

and what about the clutch point ?? will we still feel it?? i have a feeling no... because no more mechanical link if all is by wire...
The clutch point is another important aspect of the manual!

This is similar to the electrical steering... one more ties to the road being disconnected...

Can't wait to see what BMW comes up... if they can perfectly simulate the manual without any compromise... then i will be sold!

The first of the two options is an actual manual transmission where the only new electronics involved is the system that blocks out improper shifts. There is still a clutch, you still feel it, you still row the gears, it just has a safety feature to prevent shifting into the improper gear.

[southlight]

Originally Posted by Giannis

So, the actual gear has no mechanical connection to the gears themselves, just like Porsche's 7sp. manual.

As far as I know, it's not been confirmed that Porsche's 7-speed manual transmission has no mechanical connection. There have been rumors, though.

Originally Posted by Giannis

On a different page and completely understanding the idea of a fluid of some certain rheologic properties, my question is where would the limit be. Would a 5th to 2nd downshift be possible or for reasons of pure excitement, will the blocking of the (in this case) rear wheels due to an "improper" downshift, still be possible?

That's a matter of programming.

Originally Posted by DrivenByE30

It might not be an automatic, but it still not a true manual...
(can you dump the clutch?) ...

You can dump the clutch in option 1 (with clutch) as it's just a regular MT with the added security of protection against improper shifts while the drive-by-wire scenario doesn't have a clutch pedal.

Originally Posted by Neegra

I really dislike the clutch by wire idea though.

There's no clutch by wire. The first option has a regular mechanical clutch while option 2 has no clutch pedal at all.


Best regards,
south

[F80M]

So, is the 7th gearing for 130MHP + top speed video clip run? Nice. Await for more crashes news in the welcome page...

[M_Power_Fan]

i think that - in today's cars and today's technology - a manual gearbox doesnt make sense at all.

i think that DCT, speedshifts and stuff is faster, more suitable on a racetrack and paddles on wheel are cool anyway

[E9TOU]

Interesting. I'd really like to see how this patent develops. Manual transmissions for me are a huge plus and I'll continue to buy my cars with MT's as long as they're offered.

[doublevanosrc]

Originally Posted by M_Power_Fan

i think that - in today's cars and today's technology - a manual gearbox doesnt make sense at all.

I agree, well sort of. I've driving manuals for over 10 years(All BMWs) and while its fun to drive and more engaging autoboxes have made significant advances in this period. I recently drove an F30 328i with the 8 speed box and i walked away highly impressed. I could definitely see myself living with that auto day in and day out. It was fast, smooth, and economical, my only gripe was that i experienced a minor pause during an acceleration run(not sure if it was lag or what). Still as I get older I have some days i don't feel like shifting of course those days are very few. I think it would just be better to have 2 cars, a manual and an auto.