TCCoA Forums banner

1 - 20 of 35 Posts

·
Registered
Joined
·
7,758 Posts
Discussion Starter #1
OK all you “fabrication guru’s/engineers”… here’s something I’ve been rolling around in my head since getting rid of the MN12’s. :D

Instead of using a mechanical link between a clutch pedal and the clutch (whether it be via hydraulics or by a physical linkage), why not use a position sensor on a pedal to drive an electro mechanical (hydraulic, pneumatic, electromagnetic, etc.) device to operate the clutch.

The electronics aren’t an issue since it is basically a transducer arrangement and that technology has been around for a long time and I have a buddy that builds control systems for gas turbine engines for a living. :D

So here are my questions for everyone:

First off, does anyone know if any auto manufactures have adapted this technology to their vehicles yet?

During speed shifting, what is the time from when you depress the clutch, to when you release the clutch pedal? This will determine the maximum “response time” needed for the mechanical aspect of the clutch release mechanism.

In order of “speed of actuation/movement”, which is fastest: an electo-mechanical device (like how an IAC works (stepper motor), but on a larger scale), a pneumatic cylinder, or a hydraulic cylinder?

How far does a throw out bearing face have to move to completely release a clutch? (I’m thinking it shouldn’t be more than 0.25 inches, but I don’t know the “finger ratio” on the standard clutches.)


Oh, and the reason for this “thinking”… the major drawback to dropping a manual transmission into a Gen II Mark VIII is that the EEC is mounted right where the clutch cable/linkage needs to go. :bawling:

If I could get rid of everything “behind” the clutch pedal, it would be a simple bolt in to install a T-45/56. :znanner:

I know the technology is available if they can control the control surfaces on fighter jets with this technology. :D

Thoughts, pro's, con's... :thumbsup:
 

·
Registered
Joined
·
875 Posts
They already do this with the throttle on newer cars. You can look into at least one end of the system (the input) by researching that. I personally prefer a physical link between my foot and the throttle and/or clutch, but I can see why you'd be interested. Good thinking.:thumbsup:

Mike
 

·
Premium Member
Joined
·
9,165 Posts
I may be way off the mark here (no pun intended). But wouldn't it be easier to relocate the EEC? I mean if you're talking about a small metal box, you could just move it and add length to the wires going to it if needed. Or am I missing something very obvious to experts but unknown to simple folk like myself? :D

On the other side of the coin, I'm sure it could be done. But I'm like Toombs, I'd much prefer a physical link between my foot and the device being controlled (Be it a throttle, a clutch, or a brake!)
 

·
Registered
Joined
·
680 Posts
Mechanical rod is the best for consistant, John-force - like launches, but a electro-mechanical device could be used.

Most manufacturers just delete the clutch, and put the electromechanical devices inside the trans, ECU controls the clutch, and the shifting, you just step on the go pedal.. ..

This is the direction your heading anyway....
 

·
Registered
Joined
·
7,758 Posts
Discussion Starter #5
Traveler said:
I may be way off the mark here (no pun intended). But wouldn't it be easier to relocate the EEC? I mean if you're talking about a small metal box, you could just move it and add length to the wires going to it if needed. Or am I missing something very obvious to experts but unknown to simple folk like myself? :D

On the other side of the coin, I'm sure it could be done. But I'm like Toombs, I'd much prefer a physical link between my foot and the device being controlled (Be it a throttle, a clutch, or a brake!)
From what I've read of those that have done the swap already, the rewiring is a nightmare! And there's not a lot of room under the dash of a Gen II ANYWHERE!! It's packed pretty tight! About the only place to install it would be the glove box!

Then you have to worry about the master cylinder and getting large linkage type things through the firewall. With the "clutch by wire", all that would be needed would be wires that could pass through the firewall anywhere you wanted them. :D

And I agree, I like a mechanical connection also, but it seems that "drive by wire" is the way everything is going. :(

I guess I could look at the old Porsche "Tiptronic" transmission that disengaged the clutch when you grabbed the shift lever. :beek:

Keep it coming. :bowdown:
 

·
Registered
Joined
·
680 Posts
Look at the trans in the new A3, called the DSG trans,

THIS IS WHAT YOU WANT!

I think they might put the trans in certain model new a4's and passat's as well.

Very similar to the all out racing trans they use in the F1 cars.

I'm not saying it would be easy to adapt, but If you look at the aftermarket, dog-ring transmissions are being made for our applications. At a price for sure.

Now automaticing that trans, that would be a different story.

In the audi you can go full manual, clutchless with paddle shifters, or full auto.
 

·
Registered
Joined
·
875 Posts
94 Daily Driven 4.6L said:
And I agree, I like a mechanical connection also, but it seems that "drive by wire" is the way everything is going. :(
It's just another measure of control. Now the programmer of the EEC somewhere can decide how the throttle in your car will react in certain scenarios rather than what your foot is telling it to do. It just seems wrong to me that I can put my foot down and say "go" and my car just laughs at me and says "no". Scary.

Mike
 

·
Registered
Joined
·
7,758 Posts
Discussion Starter #8
Toombs said:
... It just seems wrong to me that I can put my foot down and say "go" and my car just laughs at me and says "no". Scary.

Mike
LOL!! My LSC does that now when I have the traction control turned on! At WOT from a dead stop, it applies the brakes and retards the timing... It won't let you spin a tire!! 15.4 vs 17.8 at a track!!! :redmad:

Which can be neat if you need to accelerate hard around a turn to beat traffic. Just floor it, whip the wheel to the left or right and go. No worry of spinning the back end around. Not that I have personal experience of this... ;)

There was some testing that I saw about 15 years ago of a system in England that actually applied your brakes and stopped your vehicle as you approached a stop sign! It used sensors in the road to "talk" to your car!! So you stopped no matter what. :zbash:
 

·
Registered
Joined
·
680 Posts
If my car starts laughing at me, I'm definatly going to ask for medication :D
 

·
Registered
Joined
·
744 Posts
Toombs said:
It's just another measure of control. Now the programmer of the EEC somewhere can decide how the throttle in your car will react in certain scenarios rather than what your foot is telling it to do. It just seems wrong to me that I can put my foot down and say "go" and my car just laughs at me and says "no". Scary.

Mike
go drive a 05/06 mustang gt w/ 5 speed, which is throttle by wire, the eec will hold the rev's up (slightly) while you shift, vey noticable in downshifts

i too don't like the whole drive by wire, another 15 years and almost every car will be manumatic. I remember reading last year that BMW wanted to use only manumatics in it's M-cars. Europeans perfer it (think: F-1), but the vast majority of north americans are opposed to it. (think: nascar). although, the dual clutch Audi trans mentioned above is preety cool.
 

·
Registered
Joined
·
5,978 Posts
i dont like/ trust fly by wire, something about a computer controling the engine speed while driving isnt right , and how diffrent things can go wrong, working at a ford dealer i have seen the pedal sensors go out on di turbo trucks. and and aslo a couple run aways becasue of that too
 

·
Premium Member
Joined
·
9,165 Posts
I don't mind the "manumatics" so much. I'm assuming you're talking about the dual gate type shifters where you can move the shifter over to the right and just "slap" it up and down one gear at a time. I drove a Stratus R/T a few years ago that had it. it was a lot of fun (would have been more fun if the car had actually had power). A friends 350Z has it, and though at first she had been wanting a 5-speed, she really like the slap shifter now. she can use auto when she needs to (I.E. when she has coffee) or she can use the other setting when she wants to have fun.
 

·
Registered
Joined
·
744 Posts
ircc; honda actually has a steer by wire system it's using, now that's scary

traveler~ not sure if your 'dual' comment was about the audi trans or not, but any way:

the audi dual clutch trans uses two clutches. the gears are split into two banks, odds & evens. when you're in 1st, the 'even' bank selects 2nd & it's clutch is dis-enguaged. slap the shifter for 2nd, it engauges the 'even' clutch & dis's the 'odd' clutch, the 'odd' bank then selects 3rd in prep for your next shift. if rpms & speed is droping it does the reverse of this to prepare for d-shifts. this system makes shifts quicker then a normal manumatic.

more dsg info:
http://www.automobilemag.com/reviews/0305_audiTT
 

·
Registered
Joined
·
7,758 Posts
Discussion Starter #15
I don't have a problem with "simple" drive by wire... it's only when you put a processor between the "drive" device and the "driven" device and the processor starts making "decisions" for the driver! :zbash:
 

·
02 Explorer Pioneer
Joined
·
2,880 Posts
VW was doing this in the 70's on the bugs. It was called "sportomatic" or something like that. They had a two speed trans that you shifted and the car had a clutch and a torque converter. The converter alowed you to sit at a light in gear. When you put pressure on the shifter either for 1-2 or 2-1 R etc it tripped a reed switch with actuated a vacuum servo to disengage the clutch.
 

·
Registered
Joined
·
680 Posts
tomaso12 said:
ircc; honda actually has a steer by wire system it's using, now that's scary

traveler~ not sure if your 'dual' comment was about the audi trans or not, but any way:

the audi dual clutch trans uses two clutches. the gears are split into two banks, odds & evens. when you're in 1st, the 'even' bank selects 2nd & it's clutch is dis-enguaged. slap the shifter for 2nd, it engauges the 'even' clutch & dis's the 'odd' clutch, the 'odd' bank then selects 3rd in prep for your next shift. if rpms & speed is droping it does the reverse of this to prepare for d-shifts. this system makes shifts quicker then a normal manumatic.

more dsg info:
http://www.automobilemag.com/reviews/0305_audiTT
Ultra quick shifts, almost as quick as the F1 cars, quicker than an Auto, less power robbed than most auto's, and ultra durable.

NO MORE SYNCRO's!!!!!!!
 

·
Registered
Joined
·
7,758 Posts
Discussion Starter #18
jk89cat said:
i dont like/ trust fly by wire, something about a computer controling the engine speed while driving isnt right , and how diffrent things can go wrong, working at a ford dealer i have seen the pedal sensors go out on di turbo trucks. and and aslo a couple run aways becasue of that too
I was thinking about this as I drove home... cruise control is actually drive by wire! It just has it's own EEC to control the speed. :thumbsup:

But back to the original questions... :D

We answered the first one... yes it's being done, and done well... but also well out of my financial and technological reach. :beek:

So it's back to the poor man's drawing board... :D

94 Daily Driven 4.6L said:
During speed shifting, what is the time from when you depress the clutch, to when you release the clutch pedal? This will determine the maximum “response time” needed for the mechanical aspect of the clutch release mechanism.

In order of “speed of actuation/movement”, which is fastest: an electo-mechanical device (like how an IAC works (stepper motor), but on a larger scale), a pneumatic cylinder, or a hydraulic cylinder?

How far does a throw out bearing face have to move to completely release a clutch? (I’m thinking it shouldn’t be more than 0.25 inches, but I don’t know the “finger ratio” on the standard clutches.)
 

·
Registered
Joined
·
5,978 Posts
thats true, but you still have total control over the car and the engine speed , cruise control just holds it at a certain speed
 

·
Registered
Joined
·
744 Posts
another vehicle to look at might be desiel rigs, they have 2 gear boxes, the first box is a 3 speed & controlled by air/linear actuators hooked to a switch, the 2nd is a convential box w/ 7 speeds & a clutch. [the 1st box mutliples the 2nd]

another thing to keep in mind is not just the time between shifts, but rev matching. slow shifts (non rushed, slow clutch release) allowing the engine & trans speeds to match to each other better, via allowing revs to come down and/or the clutch absorbing differnce between the two units. the quicker the shifts, the better the rev matching will need to be, or your gonna be smelling alot of burnt clutch.
 
1 - 20 of 35 Posts
Top