Engine and Transmission Tech

The stick-shifted manual tranny is headed the way of the dinosaur:

[editorial.autos.msn.com]

Yep, I'm sure paddle shifters will be the norm one day, but for the time being, I am perfectly happy with exercising my left leg.

MGBV8 Wrote:
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> The stick-shifted manual tranny is headed the way
> of the dinosaur:
>
> [editorial.autos.msn.com]
> umentid=656470

Absolutely true. But for us it will take a very long time. There will be a lot of resistance to it but eventually a tranny that is quicker, better, and more fuel efficient, that can shift correctly for all conditions and maybe even eventually, that is self contained, will take over.

I'd like to be able to keep two options. A tunnel mounted stick shift, and a vestigal clutch pedal that disengages the drive. Aside from that I have no problems with it at all.

Jim

Paddles are cool. However I still like stick shifts better, in a sports car! REAL sports cars have only two seats, and manual transmissions. I think it's carved in stone somewhere! :-)

MGBV8 Wrote:
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> The stick-shifted manual tranny is headed the way
> of the dinosaur:

So are we!

Flappy paddles are the way to go in a techno-ride - but nothing (well, almost nothing) feels better than hitting shifts just right.

There are advantages to a manual transmission car that automatics are not yet able to offer, primarily having to do with the clutch. If you think about the driving experience, the one thing that comes to mind is that you can disengage the drivetrain at any time and re-engage it smoothly, and so far automatics are incapable of peforming that function. Why is this important? Simply because there are times under extreme driving conditions when you want the rear tires to freewheel with neither acceleration or drag. As only one example but the first one that comes to mind, if you've overcooked a corner and you're just hanging in there hoping the corner of the tire doesn't drop off the blacktop you need the most lateral traction you can get and if you're slowing down that will tend to kick the rear end out. So it's a lot easier to push in the clutch than it is to try to balance the throttle. At stoplights when you want to rev the engine, how lame is it to shift your auto into neutral? And there are other times as well when a clutch can be real handy. It has everything to do with driving style, and let's face it, there's no way you're going to bring it up to 5 grand and drop the hammer with an automatic.

But they are constantly getting closer. What is important to realize is that automakers do not see any value in an automatic that faithfully emulates a standard transmission. They could make one but the motivation is just not there. There is also no chance of having an "H" type shifting pattern in an automatic at this time that emulates a standard, and as Tom mentioned the visceral feel of slamming gears is entirely missing, to say nothing of the satisfaction of a well coordinated and executed shift.

But the automatics do have the potential to provide the best of both worlds, and with recent advancements are capable and well poised to do just that, if the auto industry would only take notice and allow it to happen.

With today's computer control of shift solenoids and hydraulic line pressure along with the other advancements in transmission technology I present the following scenario as a desireable transmission solution:

An automatic transmission which uses computer control to provide the very best of automatic function, either tunable by the driver to match his/her style or with a learning capability to do the same. This transmission, as a performance model also has a console mounted shifter which makes use of a traditional "H" pattern gate in the forward or drive mode. It makes no difference how many gears are available, as long as throwing the shifter either up or down to the left is a downshift and to the right is an upshift. This "H" pattern will override the computer at any time, and give an instantaneous shift, but the computer will monitor throttle, engine speed and load, vehicle speed and perhaps other parameters as well in order to give a smooth, jerk free shift either up or down by modulating hydraulic line pressures both on release and apply of the clutches. Paddles could be available as well, but the floor shift also has the functions of park, reverse, and selection of auto or manual mode. And as we see both modes are a blend of each other in different ways. In manual mode the transmission stays in the selected gear but the computer controls the shift. In auto the computer selects the shift points as well but will always accept an override. And it learns to bring the two closer together. And the console shifter is built robustly enough to give the feel of a good manual shifter and to be capable of enduring slammed shifts. The speed with which the lever is moved becomes the determining input for the computer to determine the softness or the ferocity of the shifting action, ranging all the way from a Caddy mush to a dragstrip slam.

But there is still something crucial missing and that is the clutch. An auto has many clutch packs but they aren't generally built to handle gradual engagement of engine power. Instead the torque converter handles that task. So if the auto is built with a clutch function such as with a vestigal floor switch or pedal that causes the computer to disengage drive using those clutch packs and the driver then runs the engine up to 5 grand and drops the hammer, the modern transmission won't fare so well. That doesn't have to be the case. We have seen many many instances of racing transmissions that are capable of handling very extreme power outputs, based on old case designs, and a wet multi disc clutch is inherently more compact and has a higher load capability than any dry single disc clutch ever made. It's just a matter of designing the transmission to handle the application. In essence this means having one clutch pack in the case which is overbuilt. At that point you now have the best of all possible scenarios. And, you can equip the clutch function with a progressive, proportional control from the pedal through the computer, and/or give the computer launch/engagement authority with the pedal being a simple on/off switch.

This is the performance transmission of the future. Now if we could just convince the automakers to build it.

Jim

The rebuild price on that tranny of the future is gonna hurt!

That's a fact. So the proper way to build it is with a large enough main clutch pack (maybe with kevlar/carbon fiber) that it will not have to be rebuilt. Modern automatics usually last the life of the car these days.

Jim



Edited 1 time(s). Last edit at 11/07/2008 09:10AM by BlownMGB-V8.