XFi Main Harness Bulkhead Connector

HWYSTR455 · #1 (**permalink**) 06-30-2010, 03:39 PM

I want to install my XFi ECU inside the passenger compartment, and pass the main harness through the firewall using an aircraft or some type of bulkhead connector instead of the included 3-mile-wide grommet. I know many have done this before, what is being used out there?

-Mike

ibmtech · #2 (**permalink**) 06-30-2010, 04:11 PM

My car was orignally a 305 TPI engine and the harness that I ordered was for that model. I know the rubber grommet isn't even close as to where it needs to be. I am still in the process of fabricating a special plate for my 87 camaro for my xfi and 572.

TurboNova · #3 (**permalink**) 07-01-2010, 02:00 AM

The rubber grommet works out fine if you cut the hole inbetween the valve cover and the intake. Then you can run all of your wires out just on the top rail of the valve cover and the intake.

To answer the question though, I get this all the time building harnesses for people. The connectors most use are AMP Aerospace connectors and they are not cheap. Close to $200 ea end. I personally don't like doing this because it is one more place that you could have a problem. Now you have another 50 places for a potential problem. Really how many plugs do you have to disconnect when you take the engine out? TPS, IAC, water, air, MAP and O2 unplug the injector harness. Pretty easy really.

HWYSTR455 · #4 (**permalink**) 07-01-2010, 09:50 AM

AMP aerospace? Will have to look at those. There's a ton of other connectors out there, and I have seen custom installations using different kinds (like the one that I attached a pic of, cost is roughly $38). They are shielded, use either solder or crimp pins, and come in a number of different arrangements. As for adding another point of failure, or multiple points, an individual attempting to modify the harness usually has the knowledge to know how to ensure/prevent such failures before taking on the project, or the knowledge to troubleshoot when a problem does arise.

Sure, the 'supplied' harness works fine, and the placement of the hole where it passes through the firewall isn't the issue. The issue is that the hole needs to be like what, 2.75" in diameter!?! Like I want a hole that big in my classic? I think you see what I mean. On my f-body, there's a hole already there for the fan motor wire, it's about an inch diameter, and I plan on using that. I've seen a number of people use that hole just as I plan, and they have overcome any issues with splitting the harness.

The reason the hole has to be so big is the obvious fact that you have to be able to pass the connectors through it. I would think that it would be pretty easy to manufacture the harness with said split, the hole could be smaller, and there would be little additional cost. Because the hole has to be so big there's more of a chance you have a leak at the grommet too, because you can always find a flat surface for the grommet to seal, and not to mention many GM firewalls are a double-wall. How many initial installation failures are there due to people jamming the connectors thru a hole under the dash?

SoCal · #5 (**permalink**) 07-01-2010, 12:57 PM

I'll stay out of the To Bulkhead or Not To Bulkhead debate. But I would like to throw this out there. I've not used this DRB series before but I really like other Deutsch connectors. These are at least an interesting alternative to the more common round bulkhead connectors. All you need to do is find a square drill bit for the hole.

http://www.laddinc.com/our-products/...ceptacles.html

HWYSTR455 · #6 (**permalink**) 07-01-2010, 01:20 PM

I have the full LADD catalog(s) of the lines they carry, (the pic I posted is from the LADD site), and for most of the connectors, you need to have a PhD to order them (size, connector count, pins config, etc). I've looked at the square ones, though like I said, I have a hole that's already there I want to use, limit the number of holes I'm drilling. They're enviro sealed, locking, positive contact, and also shielded on a number of pins.

I know a number of people are using them, and I was hoping someone would chime in with a part number without me having to go through the painful process of finding the correct one.

HWYSTR455 · #7 (**permalink**) 07-01-2010, 01:31 PM

Here's a company that does harnesses as I speak of, AutotrendEFI, and a couple of pics of one of their' harnesses:

(maybe I'll call and see if they will give me a part number on the connector)