GEMS - General Engine Management Systems Ltd - Forum

Do GEMS do any sort of control system to monitor front and rear prop speeds?

I am looking to actuate a pressure pump/solenoid to actuate a Centre diff clutch pack when a difference in speed is registered between front and rear axles.

Regards
Mark

Hi Mark,
We do bespoke ACD for Mitsubishi ans Subaru and a 'generic' TC75, the manuals for which are available from our website. I think that the TC75 could be of interest to you.

We also have another system which does concentrate on Prop Speeds rather than Wheel Speeds but the output is designed for a Rexroth Valve Train and is not a current product.

Hope that this is of some help.
RickS

Thanks Rick, the Rexroth system was used on the escort cosworths iirc.

I will look at the TC75 manual.

Thanks
Mark

I've just found another relatred thread that might be of interest..... See:-

http://www.gems.co.uk/forum/viewtopic.php?f=6&t=384

BR
Rick

Interesting that Rick, Thanks.

I know the old GEMS diff controllers come up for sale every now and again for not a lot of money, worth buying then maybe and sending it for upgrade?

Regards

Mark

If one surfaces, we can certainly check it out for you. I don't think that there are any 'hard-to-come-by' components on the PCB but I will check and post here if I find anything. I will also find out if there is an upgrade path for this product and post the results here.

BR
RickS

Hi Rick,

I've been thinking, pretty dangerous at this time of the night but usually come up with the greatest ideas late on

I have an EM36 on my car, it is configured for DBW.

Would I not be able to use the ECU to control the solenoid PWM (assuming I can free another off my options list) based on speed input?

This system does not have to have complicated mapping currently.

Just a thought before I troll through the manual again.

Regards
Mark

If you have a free 'User' option and an unused PWM, it's feasible that it could be configured. I will have a hunt around some EM36 cals that I have to see if anything similar has been setup but on't hold your breath...!

What version of firmware is your EM36 running and is there a chance that you could send a copy of the CAL to the 'tech (dot) support (at) gems.co.uk' email address..?

BR
RickS

Cal sent, and Im on the latest version 01V28.

Received and put into the schedule...... Re. DBW, is the rotary pot (Act T Demand In) that is causing the throttle irregularity connected to pin A10..?

BR
RickS

Hi Rick, not with the cal/car at the moment, in the notes section I save some of the pin config detail there.

OK...... The PWM in the EM36 will not be ideally suited to controlling the Diff as there is no Closed Loop Feedback. The dedicated Diff controllers will assess the scenario and 'surroundings (past, present and future feedback)' and adapt to give the best reaction. That's what PID controllers do and although they are present and settable in the dedicated diff controllers, they aren't in the EM36, regardless of version.

True, you could set a PWM to adjust the clutch but the settings would not be flexible (or quick) enough to do the job satisfactorily. Apparently, it has been attempted in the past and abandoned.

HTH
RickS

Thats that sorted !!

Cheers Rick

Glad to be of help.
I'll get this thread moved to the EM36 FAQ section as this is not the first time that this query has been raised.

BR
RickS

RickS wrote:Received and put into the schedule...... Re. DBW, is the rotary pot (Act T Demand In) that is causing the throttle irregularity connected to pin A10..?

BR
RickS

Hi Rick,

Yes it is, (MAP2) ADR06 at A10.

Regards
Mark