Sequential shifter conversion.

[RomanV]

Ive been thinking about how you would go about making a sequential shifter conversion for a regular H gate car.

I mean looking at the SW20 gearstick, all it does is push and pull two cables in a certain sequence. Surely it would be possible to make a sequential setup.

Disclaimer: Im never going to attempt this, as it sounds like far too much work.

One Idea I had, is to have two discs, with profiled grooves cut into the side. (one disc controls the movement of each cable. The two discs would be connected with a shaft, which is moved back/fowards by the gearstick)

The cable would have a linkage connecting to the profile cut into the disc. which is restrained from moving up or down. So when the disc rotates, it only pulls the cable fowards or backwards. (eg. the cable would be horizontal with the picture, with a pin that fits inside the yellow slot in the plate) As per my quick sketch below:
http://img456.imageshack.us/img456/5223/sequen8pk.jpg
This would push/pull each of the cables the required distance to move it into the next/previous gear.

I dont think this would be practical however, as it would take up too much space.
And it would probably jam up too.
And youd have to make a double ratcheting system so the shifter can move the disc foward or backwards, but wont bring the disc with it on the way back to the middle.
Thats about as far as I got, before I got distracted by something else.

I suppose you would have to get this certified anyway, if you converted your H gate.

A quick search on the net turned up some other interesting (and more than likely, far more thought out) ideas for a sequential setup.

I thought this was quite good:
http://metawire.org/~nomel/projects/sequential5speed/

Hmmm, and now that I have a look, HSW has a good sequential shifter writeup. No surprise there I suppose.
http://auto.howstuffworks.com/sequential-gearbox1.htm

I also came across a conversion kit you could buy, from 'taikara' I think it was. To convert your H gate into a sequential setup. Cant find the link however.

Anyway, thought it might be an interesting discussion, if anyone else has thought about something similar before.
I think having a sequential setup could be a PITA, I would probably prefer an H gate. But it would be a cool novelty I suppose.
Im sure a few people here with engineering backgrounds have thought about stuff like this before too?

Or perhaps I should try sleep at 2am, instead of being up late thinking of ideas that have already been invented

[RS13]

Crap man, where do you come up with all these ideas?

It sounds like an idea, but I don't see its' practicality in a daily driver. I'd imagine creating some sort of a "ratchet" type system to be sound, but I thought that having 2 cables, doesn't 1 control the cog selection, and the other the rod angle? I just don't see how you'd manage to convert a standard H pattern without a LOT of engineering..

Have you considered a future in automotive engineering?

[RomanV]

Crap man, where do you come up with all these ideas?

I have various sleeping disorders, including insomnia at times.

Lots of time to think about things.

It sounds like an idea, but I don't see its' practicality in a daily driver. I'd imagine creating some sort of a "ratchet" type system to be sound, but I thought that having 2 cables, doesn't 1 control the cog selection, and the other the rod angle? I just don't see how you'd manage to convert a standard H pattern without a LOT of engineering..

Its more simple than youd think.
with the SW20, both cables just move fowards or backwards.
When you move the shifter to the left, it pulls one of the cable towards the front of the car. And vice versa.

There are three possible positions for each cable, foward, neutral, and backwards.
Pulling cable 1 fowards is like pushing the gearstick fowards.
pushing cable 1 backwards is like pushing the gearstick backwards.
Pulling cable 2 fowards is like pushing the gearstick to the left.
Pushing cable 2 backwards is like pushing the gearstick to the right.
So you would just have to make the cables (the 'foward back' and 'left-right' cables respectively) move to the following positions for each gear:

R: Back, back.
N: middle middle
1: fowards, fowards
2: back fowards
3:fowards middle
4:backwards middle
5:fowards, back.

They only have to move about 10-20mm each way, based one measurements taken with my eyometer.
This isnt a huge engineering exercise, I bet there is a simple solution.

Have you considered a future in automotive engineering?

Nah. I would fall asleep during my classes and fail miserably. Due to aforementioned sleep related problems. Doh!
But anyway, thats another story.
This thread's about one of my half baked ideas.

[fivebob]

Easiest way to achieve the cable movement would be to use a shifter drum like the ones found in motorcycle gearboxes, might need some sort of linkage to get the required amount of travel though.

However the biggest challenge is not going to be the shifter cable movement, it's going to be clutch activation and timing, because you still have a synchromesh gearbox, not a constant mesh like most sequential gearboxes. It takes time for the synchro cones to get the gears up to the speed required for smooth engagement, so you still need the clutch. Which really means there aren't many advantages, and lots of disadvantages, to having a sequential synchro gearbox.

[Adamal]

You REALLY need a good nights sleep, Dave.

[RedMist]

However the biggest challenge is not going to be the shifter cable movement, it's going to be clutch activation and timing, because you still have a synchromesh gearbox, not a constant mesh like most sequential gearboxes. It takes time for the synchro cones to get the gears up to the speed required for smooth engagement, so you still need the clutch. Which really means there aren't many advantages, and lots of disadvantages, to having a sequential synchro gearbox.

Just buy a sequential MRS. Completely computer controlled. It even appears to double de-clutch on downchange.

[RomanV]

Yeah I wasnt thinking of making it 'clutchless', just like a normal gearbox but without the H gate.

And yes, there would be little to no benefit from this, apart from novelty value I suppose.

Another problem would be the fact that you have to move the gearstick over to the left or right, before you can put pull/push it into gear. (unless you are in 3rd or 4th)
Which means youd have to figure this into the gearing somehow, making it even more complicated.

Theres no way Id ever want to drive a clutchless paddle shift street* car, its just wrong.

*But Id make an exception for certain high powered race cars of course.

[Leon]

A dude I used to know has been trying to build one of these for a VR4 for the last five years. I don't think he's ever quite gotten there.

[the fallen303]

my uncle's co driver made one for their wrx rally car, worked quite well. think the reason they went away from it was it was not as strong, and couldn't take the hammering of the gear changes while racing, so would lock, or not quite select the gear properly. other than that, worked extreamly well.

[Malcolm]

I've heard similar ideas in the past, here's basically how they went.

use hydraulic rams to actuate the movement of the cables - you would need a hydraulic pump on the engine (ie power steering pump maybe), a series of solenoid valves to control the rams, and some sort of microprocessor to control the actuation of the solenoids.

You could also have another hydraulic actuator tee'd into the clutch line to actuate that, so when you press the button for an upshift, the controller checks what gear you're in (it would be stored as a variable in the program), then applies whatever sequence is needed to shift up 1 from that gear. For instance if you're in 2nd going to third, first it actuates the clutch, then it pulls cable A to the center of the ram's travel, then it pushes cable B into the center of the rams travel, then it further pulls cable A to the end of the rams travel, and finally it releases the clutch. I don't know enough about hydraulic devices to know whether this would be a nice, fast and smooth shift or not, but yeah, it's an idea.

[RomanV]

Yeah I was thinking you could perhaps use big $&#$% off servos/stepper motors/hydraulics. But it means there is more to go wrong, and its more complicated. As you say, youd need micro computers, etc.

For a 'normal' gearbox, I think it would be better to be changing gears mechanically, eg. unassisted.

[bad20v]

I've got a mate with a secquential gearbox in his ae101 fxgt. Cost him about 10 grand!! Works mint but he keeps braking cv's and driveshafts... somethings to do with the direct power transfer he sez.

[RomanV]

Hold on...
AE101?
power?

Sounds like a BS story to me.

[toyonut]

i was thinking of an air shifter, just need to set up two air cylinders to control the shifter arms and some electronics on the gear shift assy to control the cylinders movement. still not easy though.

lots of time and working in a confined space for that kind of thing is no fun.

I was thinking at midnight too

[bad20v]

Hold on...
AE101?
power?

Sounds like a BS story to me.

Got your engine back from Lynn yet?

[RomanV]

Spose I had that coming.

And no.

[spencer]

i was thinking of an air shifter, just need to set up two air cylinders to control the shifter arms and some electronics on the gear shift assy to control the cylinders movement. still not easy though.

lots of time and working in a confined space for that kind of thing is no fun.

The basic micro to make it run wouldnt be hard to program but making it a smooth change would be another story. I played with hydraulics and micros at uni but I think the system would be complecated in a car enviroment. Maybe solenoid control would work better

[mr pad]

Theres no way Id ever want to drive a clutchless paddle shift street* car, its just wrong.

*But Id make an exception for certain high powered race cars of course.

Dont mock it till you try it

The DSG in the golf gti is $&#$% awsome. So much fun. Id prob choose that over a man. Faster gearchanges, still sits at the lights without your foot on the brake, sounds like a man, even blips on downchange...

Cant do skids though

[RomanV]

Cant do skids though

And what about reversing, three point turns, things like that?

It would be a PITA without a clutch.

But then again youre right, I havent actually tried it.

[TRDPWR]

cant do skids on a DSG??? try using launch control with ur foot on the gass. when you take your foot of the brake u wont have any traction till u hit 3rd. having done this in a new gti with dsg myself