Considering using a PLC to run my car

Im considering using a PLC to power all body functions on my racecar. I have done basic micrologix programming in school and think it would be the best way to save weight. I run a seperate stand alone system for the engine so thats not a concern. Currently the stock wiring inside the car weighs about 50-60 lbs running the windows, blinkers, air bags (being removed), wipers, tail lights, fan1, fan2, intercooler pump, and all other minor body functions. If I completely replaced the entire body harness with a PLC using lightweight plastic relays branching from the main power feed which runs from the front to back of the car (battery is located in back)and CAT5 cable to trigger the relays would I run into any problems that you would think of? The most sophisticated function would be the on and off pulse of the blinker... Using the CAT5 would also save time running harness connectors using standard ethernet bulkheads and connectors.

http://cz28.net/gallery/d/3012-2/DSCN1287.JPG

As you can see its a complete mess and I don't really want to touch it.

It doesn't appear that a PLC will solve all your problems. Some flexible wiring duct or flexible wireway would help.

Check this out ... I rewired my '78 Jeep with one of these, and it is so much better than the OEM harness. A micrologix would be bored sitting in a car flashing turn signals, and probably isn't good enough for engine controls.


Its a Snap

My engine is controlled by its own computer and is in no way connected to the body of the car.

If it is a "racecar" only, ie. not street legal, then why would you need blinkers, windows (electric???), fans, door locks, etc.? I would think that the intercooler and engine fans are part of the engine management system. I'm not sure what body functions are needed in a racecar, but if you want to save weight, then I would only run wire for what is needed. I'm not sure that I would trust a plc in a constant vibration environment of a racing car, but it does sound like a good starter project. I wonder if we'll start seeing posts on how to flash a turn signal with only 1 timer (need to save them bits and bytes for weight control).

Fans are part of the engine management system however there is a fuel cooling fan as well as a tranny cooling fan. I never said I wasn't going to drive it on the street therefor it will need all street functions.

What about using these?

http://www.connector.com/products_multiport.html

By the way Mercedes and Audi use CANbus. Their cars are "drive by wire"

as for my Peugeot 406 HDI I don't even look under the bonnet (hood), the last time I looked I couldn't even find the battery.

Actually Rockwell posted an article about using a Micrologix for tranny functions on some sort of a race vehicle a couple of years ago. They were talking about how much more efficient it was and how it save their equipment with precise shift points. I think he would be okay with this application. What kind of car is it? It looks like a vert of some sort. I have an 02 Mustang that I have been modifying with the hopes of someday adding a Ken Bell on. I have actually been toying with the idea of going with a 5.4 in it as well. I currently am planning on adding a complete 5 link rear suspension upgrade as well as other suspension components before I turn back to the motor.


As far as wiring harness. I would go with a flexible high quality silicone oil/gas resistant wire for flexibility, heat/cold resistance, and current handling capabilities. And only use what you need. You may save a little wieght, but not a whole lot. The problem with the choices you mention is durability. It will break at the worst times. Don't skimp here. The last thing you need is to have something not work when needed creating a safety hazard for yourself or others. Especially in a race situation.

Remember, NO street racing!

David

It is a T Top camaro, transmission doesn't use any electronics except for an optional air shifter.

I recently installed a 5.4 in a 99 mustang if you need assistance... Wasn't my choice as it was a seemingly stupid decision. You can't even remove the valve covers without pulling the engine.

Modified suspension type is going to eliminate you from competing in any sort of class that you may be competitive in.

http://cz28.net/gallery/d/3018-2/DSCN1289.JPG

Rodrigues,

Take a look at this http://www.isqe.com/ It's a new company. Looks like exactly what you're looking for. Contact's name is Chris. Give him a call.

I also post on a Cobra replica builders forum where Chris has posted a ton of info. Here's just a sample...

http://www.ffcobra.com/ubb/ultimatebb.php/ubb/get_topic/f/1/t/065015.html#000000

JohnW said:

By the way Mercedes and Audi use CANbus. Their cars are "drive by wire"

Click to expand...

Does that mean I can blame Audi for all the speeding tickets I've got in my A4?

Also (slightly OT) does anyone know if theres an easy way to switch the ABS off and on? Its great for wet roads, but in snow and ice it's about as useful as a concrete parachute.