(the E is for Easy) Inspired by BJS's Clutch Pedal Gas Restrictor [link] As many of you who own or have driven cars with manual transmissions know, when upshifting or downshifting if you rev the engine (with the clutch dis-engaged) to the rpm that the next gear will be engaged at, it makes for smoother shifting. I propose a system that would constantly monitor rpm so that when you clutch and press the throttle, a rev limiter would hold the engine at the rpm that the speed would cause the engine to spin in the gear you are shifting to next. Many factors could alert the system as to whether you are downshifting or upshifting, such as mph and how far the throttle is being opened. (ie: the system would know that it is impossible to downshift from 1st gear, or from 2nd gear to 1st over a certain mph, or from 3rd to 2nd over a certain mph, etc.) However this system would only activate with the throttle at least partially pressed so that engine braking would still be possible. Also, if you shift into a gear that would over-rev the engine (past the redline), the clutch will hold itself disengaged until the gear would not over-rev the engine.-- acurafan07, Nov 29 2006 Clutch Pedal Fuel Restrictor Clutch_20Pedal_20Fuel_20Restrictorinspiring idea [acurafan07, Nov 29 2006, last modified Nov 24 2007] Good idea. I don't want it anywhere near any car I ever own, but that's because I like to have control of these things.
I could, however, see that many people would want this feature in their cars.
bun for you-- Custardguts, Nov 29 2006 Hmmm...-- BJS, Nov 29 2006 I'm guessing this is something like how the new BMW SMT works, but I don't know for sure. All I know is that I rode in an M5 with a manual transmission that was fully electronically controlled (i.e. no clutch pedal). It has a sequential manual trans and a servo or solenoid controling the clutch (I presume), but the works behind it are most likely similar. I'm not boning this, but it might need to be looked into as "baked."-- Hunter79764, Nov 29 2006 Actually the bmw's system (aside from not revving the engine with the clutch engaged) really isn't a true manual. This is a system for people who like manuals but could do without some inconveniences, people who want the system to be smoother, or people who are learning to drive manuals and could use some extra help. BMW's system involves simply pushing the lever forward or backward to shift... Not as smooth as an automatic, nor as fun as a true manual.-- acurafan07, Nov 29 2006 What does the "E" stand for? Easy?-- BJS, Nov 29 2006 I actually didn't think of it when I made the idea... I guess "Easy" would be a good choice.-- acurafan07, Nov 29 2006 I think the solution to easier driving would be an automatic, not a modified manual.-- Chefboyrbored, Nov 30 2006 good idea but what happenes when you hill start and you need the exta revs-- balloon, Nov 30 2006 Lockout when speedo reads zero, otherwise the system won't let you rev at all from rest, when you need the extra juice most.-- elhigh, Nov 30 2006 My Mazda 5's got something like this. It's a semi-automatic transmission. It does a lot of what you listed. It includes the goodness of both manual and automatic transmissions.-- twitch, Nov 30 2006 Does the Mazda have a clutch?-- acurafan07, Nov 30 2006 I wouldn't know. I don't know about anything under there. I just know that my Mazda's got an semi-automatic transmission.-- twitch, Nov 30 2006 SMT(G) Sequetial Manual Transmission (Gearbox). It is a manual transmission, just without a regular clutch pedal. Yes, it does shift harsher than an automatic, but thats because its a standard. It's very hard to make a standard shift smoother than an automatic (not that it can't be done, just that it's hard to do). The end product of the SMT is a transmission that has the attributes of a standard (less drivetrain power loss, more direct relationship between engine speed and wheel speed, resulting in better fuel economy and better performance) that anyone can drive fast. There are so many people out there that drive manual cars that just plain don't know how to shift them right. This system does away with that problem. So in short, yes, it is really a true manual, just with extra features. (It's a BMW, isn't it?)-- Hunter79764, Dec 01 2006 Quoting wikipedia, "Semi-automatic transmission, or also known as clutchless manual transmission..." Nothing without a driver opperated clutch is a true manual. You're right it is very hard for a manual to shift as smoothly as an automatic, but equalizing rotation speeds (E-clutch) makes for much smoother shifting.-- acurafan07, Dec 01 2006 An SMT is a true manual, it has a single clutch that is operated by the computer based on the input from the driver, call it clutch by wire if you like. Automatics generally have multiple clutches that are hydraulically or electrically controlled.-- jhomrighaus, Dec 01 2006 I was referring more to the actual architechture of the the trans, not how it is operated. I guess in one way, you're right, it is an automatic, seeing as how the driver doesn't have to do much him/herself, but the transmission is still a standard gearbox either way.-- Hunter79764, Dec 01 2006 True, but manual or not I'm pretty sure it doesn't equalize the speeds. Plus what's the fun of shifting if all you have to do is tap up or down? IMO, all semi-automatics have been trying as hard as possible to be manuals but will never be as fun because of the lack of a driver-operated clutch. The E-clutch isn't designed to be an automatic, but rather smoother than a conventional manual with some nice features.-- acurafan07, Dec 01 2006 Drive, or even ride, in a high quality car with a paddleshift or tapshift manual trans (not an "AutoStick" or a full-manual automatic, but a electronic controlled manual) and see if its just "trying to be a manual" or if it is actually a much better system for many applications (but not for all of them).
And it doesn't exactly equalize rotations, but it does alter timing and torque to remove as much of the jolt as it can when shifting gears.-- Hunter79764, Dec 01 2006 Or we can simplify and put money into electric drive technologies. Or are we too used to that engine roar or hum.-- twitch, Dec 01 2006 Since they shift in a matter of milliseconds, they can't possibly have time to alter much of anything. Also I didn't say they were worse, just not as fun.-- acurafan07, Dec 01 2006 Youve obviously not spent much time on twisty mountain roads when you really want to have 2 hands on the wheel and do a lot of shifting. That is where a Paddle shift comes into its own, it shifts faster so you get better acceleration and control but your hands stay on the wheel so you can stay on the road.
There must be a reason all those race car drivers and fancy sports cars are installing those things, i wonder what it could be?-- jhomrighaus, Dec 01 2006 [jhomrighaus], the fancy sports car drivers are installing them _because_ the race drivers have them... your granddad wasn't crying out for a paddle-shift for his E-type, nor did he write it off through a mountain pass. Paddle shifts undoubtedly have their benefits for the reasons you have described, but 90% of them are sold to people who want to feel like a racing driver, not drive like one.
[edit] In a 30mph limit, for instance, I will go from first to second to fifth gear. When slowing down, I will likely go fifth to third to second to first. How is this system not caught out?-- david_scothern, Dec 01 2006 Finally got around to reading this. The idea as described has existed for many years. Some of the buses I used to drive had semi-automatic transmission - that is, is was a four or five speed epicyclic box with manually-operated electric selectors; basically the old Wilson pre-select box without the preselectors. To change up, you moved the selector into neutral, allow the revs to drop (big Diesel engine), and select the next gear. To change down, you move the selector into neutral, gun the engine and select the next gear. Just like double-clutching but without the clutch. An option with this box (though not fitted on the ones I drove) was a device called a prop-shaft monitor; basically a pair of sensors, one on each end of the box, that prevented gear selection if the speed difference exceeded some figure. So, as baked as it comes, though not, I suspect, widely known.-- angel, Dec 01 2006 [david_scothern] I can guarantee you that if Paddleshift or SMG type systems existed in the 50's and 60's that Enzo Ferarri, Lyons and Walmsley, Mr. Lamborgini and Mr. Shelby would have had them in their cars.
BMW has always been a great benchmark to watch. Their M cars have only one purpose on this planet and that is to be the highest statement of what a performance automobile should be. If they put something into an M car you know that there is a damn good reason for it that is directly related to making the car perform better. They have a track record of tweaking things and adopting new technology even when critics and customers alike have cried bloody murder, but the cars always get better.-- jhomrighaus, Dec 01 2006 I wouldn't dare claim you didn't know what you were talking about. However, I have no such scruples regarding the average petrolhead. It's beyond doubt that an SMG makes you go faster; it's been demonstrated time and again. Nonetheless, I maintain that the majority of people that buy, say, an M3 or 911 buy it because it has posing power.
Being able to bore people down the pub about its fancy gearbox, fantastic torque, amazing launch control you get by pressing cool hidden sequences on its controls, etc, is also a bonus. But what percentage of these awesome expressions of modern technology ever see a trackday?-- david_scothern, Dec 01 2006 That will of course always be the case in all things expensive, however I would be careful to generalize that such devices are there for the purpose of sales(some are of course) A lot of people who can afford to drop 100K on a car also happen to be succesful and driven individuals. Many of them are buying that vehicle because it is the best at what it is. Any poor sap who knows nothing of cars quickly trades in his M car for a Rolls Royce or a mercedes or a 7 series cause cars like M's(and AMGs, SVT, TRC and all the others) ferarris, Lambos etc are not fun cars when used for "normal" driving. they are stiff, loud, rough to drive, expensive to operate etc. The people who own them are generally people who know what they have purchased and have taken the time to learn how to use them. At least thats my Opinion of course.
At least for BMWs i think it is more than you think that see real driving, but there are for sure posers out there to. Im not sure why but it seems that certain Marqees get more petrolheads than others. though rememeber that most of these companies produce a lot of regular old cars(318s 528, 740s) that most certainly end up in the hands of housewives and prom queens but when you get to the M, AMG etc things start to change due to the cost of those vehicles.-- jhomrighaus, Dec 01 2006 I think we're saying more or less the same thing, just disputing where the boundary between proper driver and poser might be. Hey, what would I know anyway? I drive a Nissan, and not a quick one either...-- david_scothern, Dec 01 2006 I drive a BMW and it has this really cool shifter thing like they have on racecars and the girls love it.........
Actually it doesn't but anyway;-)-- jhomrighaus, Dec 01 2006 As a clutch and transmission engineer I find this idea somewhat interesting. It might be too costly for American standards when it comes to manuals as we don't have any electronic gizmo boxes associated with most manuals save for the backup light switch, but I'll throw it at my boss just to see what he says. Bun from the only guy on the board who could feasibly make it happen.-- RayfordSteele, Dec 04 2006 random, halfbakery