Geoffrey

Happy holidays everyone. Now that the holidays are over I can get back to working on the car. The car is largely assembled now and I'm working on the wiring of the car. The factory wiring harness weighed in excess of 55lbs not including the fuse panel. It is also a gooey mess of tape and low grade wiring. I'm going to wire the car from scratch using Raychem M55 spec wiring and covering, the same as I use for all of the MoTeC installations. This should reduce the weight significantly and has much better current carrying capability. For instance, a 20ga wire is rated for 20amps. There will be 4 major harnesses in the car, 1 chassis, 1 engine, 1 ignition, and 1 data acquisition harness. I started by drawing out the wiring schematic using Visio, then using Excel create a pinout for every connector which tells its origin and destination as well as function, pin number, wire color and size. This is critical to do to get it wired properly from the start. Here are a few examples of the diagrams and a picture of the ignition modules and main milspec bulkhead connector for the engine compartment. The engine will drop with one 41pin connector leaving the engine wiring on the engine.

C4Russ

My wife accuses me of perfectionism. I'm going to start showing her these posts so that she can learn that I'm but a boy compared to Geoffrey.

As typical, this is awesome, detailed and well-thought out work on your part Geoffrey. While I may never build a race car, I've learned alot reading your posts with regards to planning and executing any project. You are an inspiration to me beyond Porsche cars.

Tom W

Geoffery, would you be willing to share the Excel sheet? I'm in the middle of the carpet/sound barrier removal and given the sticky mess and excess wires going all over, I'm contemplating a rewire too.

AVoyvoda

Awesome. What sort of weight savings are you projecting?

Geoffrey

Tom, you have PM.

I personally would not even attempt to disturb factory wiring since the factory wiring diagrams are excellent and allow for easy identification and repair. They also are good solid pieces and once you begin to cut and solder in the harness it degrades it and will accelerate premature wear. A wire harness should never have any solder and should be crimped from connector to connector using the proper tooling.

I am hoping the entire car comes in under 2100lbs, but am expecting something under 2200lbs total weight with air jacks, ABS-5, centerlocking wheels, 332x32 and 322x28 brakes.

hawk911

Again, you are an inspiration to us all.

Lorenfb

"A wire harness should never have any solder and should be crimped from connector to connector using the proper tooling." - Geoffrey -

Not true! ALL good long term electrical connections REQUIRE a solder connection.
This is exemplified by wiring problems which occur on the older Porsche cars
where just a crimped connection was used. The connection becomes oxidized and
results in a higher resistance connection. Problems do occur when an acid core
type of flux is used, though.

Bottomline: Always solder wiring connections for long term reliability!

Geoffrey

Hi Loren,

I respectfully strongly disagree with your statements of soldering. When you solder a connection, you create a situation where you have an inflexible joint (the solder) and a flexible wire. After a period of time, due to vibration, age, oxidation, etc., the wire will break at the joint because it flexes and the solder does not. While I do agree that older Porsches have wiring issues due to age, etc, I disagree with soldering.

My experience comes from Raychem and Deutsch wiring programs which are used in aircraft wiring and almost every professional race car. You will not see any soldered connections in those environments, nor do they have the issues you mention. Part of that is the quality and construction of the wire used, but also the sealing from the elements using proper coverings. A properly crimped connection is stronger than a soldered connection and the wire will break before the connector comes off. However, you need the right tools and I have over $2000 worth of crimp tools for the various connectors I use with MoTeC wiring.

Leave the solder at Home Depot.

Lorenfb

"When you solder a connection, you create a situation where you have an inflexible joint (the solder) and a flexible wire. After a period of time, due to vibration, age, oxidation, etc., the wire will break at the joint because it flexes and the solder does not." - Geoffrey -

That's a mechanical issue which does negate the electrical aspects.

Geoffrey

Here is the fuse panel assembly for the car. Matched to the diagram are two fuse panels, one has constant 12v+ power from the master battery cut off and the second panel is switched power 12v+ via a relay from the master on/off switch (same as tuning your key to the on position). I included a digital hour meter which will display the running hours of the engine. It is resetable and will display the hours used, and when the fuel pump is turned on (via the ECU) it will begin to record the hours used. Also included in this panel is the BOSCH Diagnostic port for the "Hammer" or PST2 tool which is required for the ABS-5 system for testing and bleeding.

Don Nguyen

I was wondering if you happen to still have the excel of the wiring schematics that you have pictured in your thread here:

My e-mail is donathon@gmail.com

Any help would be appreciated!

thanks.

-Don