Fifi

I have just aquired a V3 RA motor and Tranny with a complete wire harness. The only trick is... the chap I got it from didn't have the DCCD ecu or ECM.
For the ECM there are more options, find an STI or visit many of the aftermarket ECU manufacturers. but for the Center diff I was thinking of two ways...
1) Find an diff ecu.
2) Figure out how the Diff ecu communicates to the Diff. I know the diff runs on a 5V signal, but is it a pulse signal or a variable 0-5V signal?
Any suggestions?

Thanks
Steve

Fifi

I've found out that I can get a DCCD ecu from either STI or an aftermarket one.

But I would still like to know if I could just hardwire it to being on or off... well locked and 65%.
Does anyone have any insight?

Thanks
Steve

MorayMackenzie

If you run without a controller attached, you get the fully open position, which is the fun one.

Fifi

Is that a hint as to the ablility or inablility to run the DCCD with out it's controller? I've found one place that will sell it for $1100 CND which seems rather pricy seeing I can get the engine ecu for 1/2 that.
This is for a rally car and an on/off solutions is not a terrible one.

Thanks
Steve

greasemonkey

You can run the DCCD without its controller, but as has been said, it'll be stuck in the "open" 36:64 position.

It'll work, but if you're thinking about driving the rallycar quickly, you'll need the rest of the gubbins...

MorayMackenzie

On tarmac, the diff is great in fully open position... it's definitely rear biased, but still four wheel drive when you need it. It's very rare that I feel a real need run with more lock on the road... even in the wet... but hey, my other car is (until it sells) a BMW E30 M3.

So, in summary... I would go ahead and fit the diff for tarmac use... and fit a diff controller at a later date. Depending on the competition rules you have to adhere to, you could always skip buying and fitting the OE controller and go straight to an aftermarket dynamic centre diff controller, like the one Town End Garage developed for their rallycar (now in the hands of GEMS, apparently).

Fifi

Thanks,
so I can run it as open and have some really good drifting...

Has anyone tried manipulating the signal without the controller.
Like if I hook up a 5V source to the DCCD would that 'Lock' it?


Steve

greasemonkey

You'll have a bit more than "really good" drifting if you run it fully open on gravel

Moray, things may have changed since last I saw one, but the TEG Sport diff controller still needs the OE diff electronics in the car. It didn't connect directly to the gearbox, it connected via the standard diff ECU by scotchblocking the thumbwheel wiring.
Thus, as far as the ECU was concerned, all that was happening was that the wheel was constantly being "twiddled". I daresay if Mr Felstead installed one, his car wouldn't know the difference

MorayMackenzie

Fifi,

IIRC, the diff requires a PWM controlled 12V supply to control the magnets... a constant 5v is not a good idea IMHO.

Moray

Fifi

Thanks Moray I was last told that it used a 5V source...and excuse my ignorance but what is PWM?

Stve

greasemonkey

Pulse-width modulation. I can see your next question coming...

Fifi

lol... no I know what that means.
My question is though, do you know the pulse width when it is Locked? I could build a PW modulator and just feed it the signal it required.

Steve

MorayMackenzie

If you can build a modulator that handles the current, then just slap a pot on to adjust the duty cycle and you have a diff controller.

Fifi

Well what really ment by I could build it was I know this guy who could build it. Now all I have to do is get it into the car.

Thanks for the help.

Steve

Fifi

Would you happen to know what frequency range is?

Thanks

Brady

So the pulse varies from zero to infinity? Would a standard 555 controler hooked up to a pot and a 12V SCR work?

Or like a light dimmer, could a rc circuit work?