cmcraeslo

Hey guys.

I'd like to share with you guys the project I was working on for the last 2 years. It's fully pneumatic paddle shifter system for any cable driven H gearbox. This is at the moment mounted in VW GOLF 2, FIA E1 hill climb car. That being said, this can easily be mounted on any mitsu lancer evo gearbox.
The ECU that's controlling the valves can also control the clutch so one could use this on syncro gearbox also. Average shift I get is 0.08s which I'm looking to improve. I still have few miliseconds left.

I'm constantly trying to improve the system so comments/ideas are more than welcome. At the moment I'm making the system a little more compact, with smaller valves, putting everything in a box, with nice connectors and so on..

More pictures & videos of the car on my facebook: https://www.facebook.com/mmemotorsport

Youtube video:


p.s.: sorry for bad video at the beginning of the movie. I'm an engineer, not a professional camera guy.


Thanks!

Marko

EVOizmm

iTrader: (10)

How are you cutting power for shifts?

What ECU are you using?

cmcraeslo

Hey there.

Are you referring to the engine control unit (ECU), or the gear control unit (GCU) ?

For engine, i'm running Megasquirt 2.

For gear control (the unit that shifts these cylinders and does the blipping & so on), I've designed the unit myself. I also made software so I can control everything with it. The small black (square..ish) box that has "MME Motorsport" on it, that's it.

I've been designing paddle shifters from 2008, but all of them were for sequential gearbox or some H-to-sequential converter. This idea was "bothering" me for a long time, so I added this support to the unit. It works great and I'm really happy with it

Edit: I just saw that it was I who actually wrote the ECU in the first post, so I appologize for the confusion

Construct

iTrader: (4)

Very cool! That's an awesome project.

I think EVOizmm was asking how you coordinated with the engine management system to cut engine power during gear changes.

How do all of the transmission bits and pieces hold up to the force and speed of the pneumatic shifting? I'm assuming you can adjust the pneumatic system to limit force and speed to balance against the risk of bending shift forks.

phizzalot

iTrader: (3)

Nice work, can you share any information about how this will work with a synchro transmission and activating clutch..

Your work looks really solid!!!

cmcraeslo

Hey all. Thank you for all your positive comments. That means a lot

You have two options to reduce the engine load, either by cutting the coil power (wired externaly through my GCU) or by telling the engine control unit to release the load. Latter is prefered, because it gives you much smoother and controlled cut. As long as the gear is not 100% in place, the cut must remain. I don't do any cutting in the video. To my experience the best way to reduce the power is to retard the ignition. How much, it depends on the engine. This way it really gives you smooth release so you don't hear this annoying hesitation.. Also, when revving high and maybe hitting the limiter, if you cut the engine spark, it will actually not release the load, becuase you're already cutting with the limiter and just cutting the spark, will not release enough to shift.

As to the speed and force.. that's easily adjustable with pneumatic, but speed actually helps the reduce the wear with dogbox engagement. The only thing that needs to be met is the movement limit. The limit must be set with the actuators, not the gearbox.
That being said.. perfectly tuned pneumatic system puts absolutelly no stress on the gearbox when done right. I added very details (100 hz) datalogging feature to the GCU so I can monitor the cable movement very fast and I can easily see if the gearbox is struggling with shifting into a gear so I can adjust the retard or increase blip degrees and so on..

For syncro gearbox, I add pneumatic clutch actuator. This means, my GCU can press/release the clutch when I want, while still allowing the user to press the clutch anytime he wants. The problem with pressing & releasing the clutch is that when you up shift, you need to release the clutch as fast as possible and with down shift, you need to slowly release it, so you get smooth and safe shift. This is why, I added what I call a 2 way clutch, which is actually two different valves I press to activate the clutch. If you upshift, the clutch releases fast, and when you downshift, the clutch releases slowly. Speed is easily controlled with a speed valve.

Hope that answeres few questions..

Marko

gr8stevo

iTrader: (4)

Marko, hats off to you my friend. This is some great work and I am glad to see you have pursued this. I am even more impressed and interested in the software and control. Have you considered clutch complete control?

cmcraeslo

Hey.

Thanks!

By complete clutch control, you mean completely without it? Like in automatic gearbox?

03whitegsr

iTrader: (8)

Pretty awesome stuff.
Nice that it's "universal" in application.

Looks like you have three different control boxes? MS (black larger box?), GCU (black smaller box?) and what is the third (silver larger box)?

cmcraeslo

Thanks.

The silver large box is actually a wireless power distribution unit. I designed it so I can control every device (ecu, gcu, steering pump, fuel pump, engine vent, ..) in a car via steering wheel console (I don't have anything else but the console in my car).
It powers my complete car, without relays or fuses. I configure maximum current per output and other conditions as well.

Marko

ReaperX

iTrader: (5)

What would what be the cost of a setup like this for our cars?

cmcraeslo

Hey guys. Sorry for delayed answer.
Estimated cost would be around 3500 eur (Europe based). For someone from US, it could be cheaper. Parts in US are somewhat nice for the wallet (compared to Europe).

marck_c

How much do all the components weigh? Solenoids, compressor, lines, ecu, etc.

cmcraeslo

To be honest, I don't know exactly. Not very light I'd say somewhere 10 kg. Shifter in the video is a prototype with heavy components. It could be much more optimized. I'm doing the optimization as we speak, getting smaller valves & cylinders. They are much too powerful for this application, but early optimization is root of all evil

marck_c

10kg is way heavy. I did think the cylinders depicted were a bit on the large side. But I guess proof of concept is more important at this stage. Have you considered in a future iteration, mounting the solenoid assembly directly to the shift levers on the gearbox? To reduce the play in the cables.