Mk2 GTi Syncro Build - Operation MOT

Yeah I mean it clearly does work based on those videos in that thread, and the screen issues could be rectified, but I think the CAN bus option is a neater, albeit more complex, solution.
I guess because Haldex 1 uses a kind of swash plate mechanical pump, you can achieve lock when moving without using the electric pump. But if you wanted to get lock when stationary, for launching for example, then you need the electric pump. Without the electric pump the Haldex will be slow to respond too because the system isn't fully primed

 

SSP 206 and SSP 238 are worth a read. 238 has a really, really good practical example of CAN-Bus on Page 18 onwards.

206 is quite easy to understand, just takes some diagram staring to get your head round it. Basically if you removed the valve and electronic you'd have a TORSEN diff, but with hydraulics and clutches. So as soon as you start to get wheel slip you'd be rocketing up towards 100% lock. The valve lets the electronics of the car limit this so the lock is as aggressive, and can be deactivated during braking and ESP activation for example.
The pump is basically there in the "stock" system to hold a constant 4 bar "Pre-pressure" in the system, so the slack in clutch pack and main pump pistons are taken up. This permits a "fast clutch response". The HPA controller etc. and OpenHaldex in theory can take to control of this pump to build more pressure when stationary and actually make the clutch lock when there is no wheel speed difference (not possible with the stock config because VW didn't put in a feature for people drag racing their cars)

238 is a good for CAN-bus but a quick explanation is it's a broadcast bus. So every device just splurges all of its data onto the bus using certain ID's. Then any device on the bus can take advantage of that data. So no matter where you tap into the wires, you'll see the same thing, and in most cases, there is no specific instructions on the bus like "Haldex do this". Its almost always just a selection of data then any connected device can decide how to interpret it. That's why the OpenHaldex project is a challenge, and why the HPA controllers are expensive. Because its very hard to isolate what the exact pieces of data are required by Haldex, and what pieces of data are just random things being sent out by modules for use elsewhere in the vehicle

Hope that crash course helps!

 

All the SSP's are good, sometimes they're a bit vague but you can learn a huge amount from them and the diagrams are very useful.

Hopefully we can get somewhere with OpenHaldex before you buy one, I still think something like this but with Haldex lock would be very cool for a stock look.

 

Woohoo, nice to see colour inside, good on ya.

 

I love updates like this!

 

Great to see Sam, keep chipping away at it!

 

good to see you cracking on mate!

 

haha i did the same last week, but with the use of the Freezer, vice and a large socket. Having the press makes life so much easier

 

Love the idea, but I think may be a little low there, what about moving heater control panel to sort of double din the original radio hole.
Saw a mk3 with similar up in the dash, admittedly the heater isnt so much of a problem there.