Tidying up wiring in race car

[CamB]

I have a ummm, Porsche race car (ok, so it is a BMW ) which needs most of the wiring to be tidied in the engine bay.

What is the general consensus on the best way to do this? I mean what material to "loom" with. I am comfortable with any moving/cutting/soldering etc of wires required. I am worried about how to bundle and protect the wires.

Is it lotsa careful looming with good electrical tape? It is split loom? Is it something else? It obviously has to deal with a fair bit of heat (5000+ revs for extended periods of time).

Thanks for help

[304065]

Cam,

Nothing like keeping everything neat. I recommend you go one of two routes: either heat-shrink tubing, which will be abrasion and temperature resistant, and analogous to the blue rubber insulation that was originally on your '02's wiring loom (at least it was on my '75, that I got at age 15!) or spiral-loom, which can be used around components too big to fit down the heat-shrink. Either are available from action electronics:

http://www.action-electronics.com/3mhs-prc.htm

I do NOT recommend, for aesthetic reasons, the GM-style cylindrical split loom, unless you wish your tii to resemble an Olds Omega or other scheissenwagen! It also holds water.

Under the heat-shrink I recommend zip-ties to make wire bundles every couple inches or so. You want it to look like the inside of an airplane-- everything positively located so it can't flop around.

Why are you only revving to 5000! REV that thing!

[TimT]

here in the states they sell these spiral kind of DIY wire looms, they come in different diameters so you can start with a big bunch of wires and transition down to just a few.

You just keep wrapping around the wire loom and let out wires here and there when needed. They are made of PVC I believe so keeping the loom away from intense heat sources is important

[CamB]

Thanks guys - it already has lots of the spiral looming, which I am not a big fan of for aesthetic reasons. Mind you, it is in "clear" colour - if it was black it would look much better. Geez, I am ANAL. Maybe if it was black I would be happy. I agree the split stuff is inexcusable.

John, I'm not revving BELOW 5000 revs. It hits the limiter (6600) 2/3 of the way down the back straight...

Thanks for the other tips (and keep them coming for anyone else!).

CAm

[Roland Kunz]

Hello

Think about what you need and where to have the fusebox and the switches and circuits then where would be a connector usefull.

After you made your mind up then organize the material.
Use aircraftstuff. Run thin signalwires to switch relays direct on the power demanding source.

Don´t solder if you are not a solder expert.

Bundle them like Porsche did it with the old versions. Just roll some tape around it like a spiral and then you have it bundled but still can see the colors or the single wire for troubleshoot.

Integrate a big connector to hook up a external battery or a high amp start booster.

Integrate the cut off switch and think about reloacting the battery to a usefull spot ( not allowed in some race classes )

Run two complete independend wire setups to a dual fuelpumpsetup.

Wrap the wireloom or run it in heat protection hose on the hot areas.
Also run it so thyt it will not get shortent anyhow if you have a slight fenderbender or step out of your car in the dark

Grüsse

[911pcars]

While I'm in agreement with most of what was suggested, I would opt for a more practical system that provides accessibility for service, troubleshooting and modification. Unless there's something better, I would use split loom. Secure it at intervals with zip ties (removeable kind even) and use Adel clamps to hold it against the body shell. So what if GM cars use split tubing? Plenty of other manufacturers do as well.

Heat shrink tubing is fine for short lengths. For a main wire harness, it's not practical to reinstall. As for harness tape, I don't see unraveling, then rewrapping 10 feet of harness to locate, replace or add new wires to the circuit as a good use of time during a race weekend, but then again, there are 24 hours in a day.

If we're talking about a permanent, factory-like install, then go with what the factory did. A race car has a higher rate of maintenance than a street car. Why not make it easy to work on?

MHO,
Sherwood Lee
http://members.rennlist.org/911pcars

[Roland Kunz]

Hello

Electric is done once and then right. You are not interestet to work on electric circuits later. Bundeling the wires makes sense. using PVC split tube has some advantages and some missadvantages. The missadvantage is that they wight more and you need more time to work with them. They also tend to collect dirt. there advantage is that you can add on additional wires and repairing on the fly is easier.

The best way for beginners is to start with the switches and circuit brakers and run normal wires bundled into differnt looms.
Bundle with what you like if you prefer asthetics than aplay everything nice organized doesn´t matter what you use.

Then use the car and wait how everything developes and modify as neede and after you find the optimum you get the expensive stuff and make the wireloom to the best standards.

This methode also helps saving costs at the begining.
When you start racing you have no real idear about what you need and what makes sense. Using aircraft material and tricking out the wireloom maybe saves 2-3 kg´s but same wight can be saved somwhere else much cheaper.

Grüsse

[CamB]

Roland wrote: "When you start racing you have no real idear about what you need and what makes sense"

Never have more more true words been spoken

I haven't got to the wiring yet, but have helped out removing sound deadening and watched while the roll cage and seat mounts have been welded in (I didn't watch the welding ).

It is coming together ok. I have weighed everything that has come out - about 95 kg inclduing a tow-bar (trailer hitch) assembly (10kg)!! About 50kg is going back in (front seats, roll cage and fire extinguisher and miscellaneous), plus I am getting a fibreglass bonnet. Total weight saving will be almost a person-worth. I am happy.

Thanks for the help - I think for the moment I will just re-loom the wires temporarily until I am confident everything is working well, then I will embark on a full tidy-up.

[Kevin Stewart]

The best way would be to sell and buy another Porsche , Just kiddng, I would go to the local track with a camera and take pictures and ask questions, junk the stuff you dont like the looks of and copy others stuff you like, Kevin