Good evening:

Does anyone have experience /recommendations for shops with expertise in producing custom motec wiring harnesses for a 4L build/ITBs? Thanks again!

 

Got mine for the 4L build from Rasant.
https://rasantproducts.com
https://rasantproducts.com/collectio...agement-wiring

Rasant Products appears to have been acquired by Group 2 in the Seattle, WA area (Facebook posting).
https://g2motorsports.com

 

That's wild, I did not realize that a custom harness is ~$8k, ECU not included. I'm sure they're very nice and labor-intensive to build, but that is a pretty penny.

 

Got mine from Rothsport racing. Not inexpensive.
Designed for their 4L build components but you should be able use it with maybe a few connectors changes.
Note part number.

 

What model ECU do you currently have? Have you considered making an adapter that would connect to your existing harness? I think it's much simpler and cheaper. Several (many?) here have done it - you can find posts by NineMiester et. al. on here about it.
Apparently it got difficult to find the male (PCB side) 88-pin bosch connectors, for making them, but you can find them now on ebay and other places fairly easily - I think because of the prevalence of alibaba and small supply from makers in china. So you just put one of those connectors on a PCB, and put that PCB in a small box that acts as an adapter, and use short wires from the PCB to the Motec, and run a much smaller custom harness out of the box for whatever connections that are not part of the standard harness.

Couldn't find the thread where Colin was talking about the availability problems with those terminals, but found this one....
https://rennlist.com/forums/993-foru...onversion.html

 

That's a very interesting suggestion. Thank you very much. I don't know enough about the ins and outs to know if it might be suitable - but I'm all ears!
Motec 130; 4.0L; AT power ITBs; high performance billet heads etc.

what do you think?

 

My understanding is that it works better with the 96+ Varioram cars with the 88-pin M5.2 ECU because they have more wires in the harness and more sensors on the engine side, and more to be controlled in the engine, but as far as I know, it should all be doable.
I've never done it myself, I've only done some research on it. I too spit-out my coffee when I saw that wiring harness prices - often more money than the ECUs! Yes, they are beautiful and often made with higher-grade parts than the originals, but still...
I mean no matter what you're going to have wiring for the flywheel sensor, knock, O2, ignition, fuel injectors, etc ... and all of that wiring is going to be the same regardless of ITBs or displacement, so using the existing harness as much as possible seems like a good idea to me (assuming nothing like water damage or whatever).

I was given a recommendation for Motec setups on 993s; someone named Ivan at IMA Motorsports in Virginia. Haven't spoken to him though as I decided to just get my M5.2 reprogrammed for now.

 

That really makes sense to me and I appreciate your insight here.
I will give them a call on Monday!

 

You should question my credibility as I kept saying 80-pin when it’s actually 88-pin -LOL! Brain fart, corrected my posts.

Perhaps I’m being naive and missing something, but as mentioned, the connectors now seem to be very easy to find: https://m.aliexpress.us/item/3256801...andl_shipto=US

Bosch used these same connectors on ECUs for quite a few cars of that era, so it’s not surprising they are in demand.

If Ivan is more focused on the Motec programming / tuning side, then you also might want to reach out to Colin Belton at NineMiester and see if they’d have any interest in making an adapter for you. He’s a great guy. It’s still going to be pricey and a wait if you’re not going to DIY it, but much less than a full harness

 

Not defending any pricing, but it is not just about the parts, but the knowledge to get something that is purpose built and functional out of the box. When paying an engine builder to build / modify / repair / debug a wiring harness, the hours add up quickly. If DIY and proficient with wiring diagrams and assembling connectors, a lot of money can be saved - just traded for your time. YMWV.

 

Feel free to defend the pricing - I get it! These wiring harnesses are not being made by machine by the 1000's - they are bespoke items, and it's a time-consuming process to make them and make them right so that nothing breaks or melts when under stress. If it were a question of making a whole harness with all the right wire lengths and all the different connectors on the ends, I would absolutely just buy it, and while I had some sticker shock, I think the prices are reasonable for all the reasons you mention. It's certainly a matter of priorities, and may ultimately depend on who (or if) you can find to build it for you if you're not comfortable DIYing it.

 

No affiliation, check out technica-racewire. Milspec wiring harnesses are labor intensive to produce, concentric twist takes a lot time. You can save yourself some money if you don't need glow in the dark milspec by going with "standard" style wiring harness.

 

Just wanted to circle back here. I was introduced to Charlie Martinek from Renngeist. I am so impressed. We had a chat on the phone and he is extremely knowledgeable and friendly. He likes to do things the “right” way but is very fair. I received a quote with options and we came to terms right away. I am more than ok for paying for his expertise. He ordered all the parts within a day and started on the harness quickly. From what I gather; this type of work is a bit of a lost art. I couldn’t recommend him more highly.

 

Glad to hear you found someone. Gotta admit, I'm totally jealous of you and @Kein Ersatz ... 4L ITB with a Motec is bad-***! Please post pics of all the sexy engine **** as you go along!