NineMeister

Since MC is rapidly finishing the assembly of the car, his next priority is to finish the interior and install the seats but before he can do this we have to install the Motec system, so this is what I have been working on for the last week.

Previously I have always designed the Motec wiring loom and sub-contacted out the manufacture, but even though I measure everything perfectly and draw it out exactly, for some reason or other I never get a perfect job and have to wait weeks for the loom to arrive. Since we were doing everything else on the this car ourselves (and Geoffrey is a few thousand miles away!) I decided that I should bite-the-bullet and have a go at making the loom myself, so here is the result:

Stage one was to find a handy piece of 8x3 plywood to make a layout table from, then draw out the loom full size onto the table top. The easy bit was pinning a few dozen nails at junctions and plug locations - at this point I was definitely thinking "how hard can this be?". I made a wire spool holder for the end (didn't have the heart to tell our cleaner to stop looking for his favourite old broom...) and screwed it down to the end of the table so I could draw off the wire as required.

The system was pretty much a copy of the proven set up from my 993RS with the exception of using a single M&W Pro-14b twin-output CDi module rather than my double Pro-10 set up, so I already had a fair idea of the connections required. I did a quick pinout of the Motec M600 ecu, Pro14b CDi module and Motec TC multiplexer, then started laying out the wires to suit. One thing to note is that we decided at early doors to cover the loom in Porsche loom tape rather than the more popular heat shrink, so this made my job easier as at least I did not have to plan ahead with shrink tube overlays and junctions.

The hardest part of the job was the mounting of the units under the seat. I found that the standard Porsche ECU plate was completely the wrong shape after we cut out the access holes for the seat belt anchors, so in the end I decided to make a fresh plate in carbon fibre. After taking a pattern from the floor I made this yesterday, then mounted the M600, TCmux and CDi units, a pair of fuse holders, a start relay (necessary for the 993 DME relay configuration) and cut out the castelated mounting slots to accept the standard 14 pin car loom connection sockets. Having mounted all the parts on velcro, terminating this end was relatively easy although it takes some fiddling to get the wiring to "look right".

The photos are pretty self explainatory but please excuse my pinout and wiring scribbled notes, done in the early hours one night because it was the only time I could get enough peace & quiet to get my head around everything!

maurice97C2S

Great work, Colin .. the c/f plate certainly adds a little class !

cheers, Maurice

Bill Verburg

Tell us why that particular ignition was chosen, Are there other options? For instance, my neighbor just redid one of his Ferrari's w/ dual MSD, he's raving about how well the car runs now.

NineMeister

Bill, I think Geoffrey covered this some time ago, certainly his is a better voice than mine on the subject. As far as I understand, when it comes to ignition the choice between CDi and inductive is pretty much down to personal preference & my preference is for CDi.

Naturally as a distributor for M&W (which came about from their links with Motec) I fitted a pair of Pro-10 units on my car to test them out a couple of years ago. As a result I have nothing but praise for the system. At the time I fitted it measuring the performance gain over the stock inductive system was difficult - maybe 2-3hp at best - but the engine was definitely more responsive with the CDi system operating. I have since used similar packages on other conversions and they have all been totally reliable and given similar results.

As I mentioned in the text, the unit shown on the photo is a Pro-12 which is there only to mock up the mounting plate and loom, the actual one being used is a Pro-14B which is the new dual coil Porsche specific unit. Incidentally, anyone running an old 911SC, Turbo or 2.7 should also be aware that M&W make 3 pin and 6 pin compatible replacement units for the very expensive Bosch modules.

trophy

Do you run this CDI with M&W coils through the stock distributor?

CWay27

a lot of patience. Bravo!!

seanuomo

Hi Colin,
That's amazing!!! I am doing my 993na to turbo right now and I have some trouble with the wiring. If you can help to send the clearly photos as you posted or any information will be much appreciate! Thanks for your time-

Juha G

Hey,

Can you be more specific about what kind of problems you have with the wiring. Maybe I can help as I have installed Motec M600 on my 993.

seanuomo

Hi Juha,
The original na DME is 55pin and the turbo's is 88pin, I have the wiring diagram for the 55DME but just can not find the completely sheet for 88DME. I solved most problems but can't be sure with the X4/2 connector pinout- Thanks for your kindly help.

seanuomo

This comes from M5.2 SHEET 5B



All I need is where the X4/2 pinout goes to...

NineMeister

I had a look through my Motec notes trying to find the originals of those pinout notes that I photographed and came up blank, unfortunately all I have on file is the low res photos. Here is an enhanced version, may be of some use:

Juha G

I just sent you the complete diagram for the 88-pin ecu. I also sent you my Motec wiring diagram.

H.H.Chinn

Lovely wiring loom Colin! You can go into production now!

NineMeister

Great! Is that an order?