Weight and Wiring

[backformore]

In case anyone is bored, I thought I'd crack open a can of worms. I did a search but didn't really find anything significant specifically dealing with the following question.

Several people have addressed modifying the wiring harness to remove wiring as a way to reduce weight. Several items are specifically addressed as being allowed to be removed either "in their entirety" or "including all associated wiring". (radio, cruise, wipers, washer, etc). No prob.

My question is what other wiring are people removing, and what is the rule allowing it. If your car came with several trim levels, some with lots of electronic goodies, and some without, I can see removing stuff and wiring IF the different trim levels had different harnesses/sub-harnesses installed.

My car's Spec line is for a single trim level that came with all the basic electrics (mirrors, locks, sunroof, etc.). A good example of my question would be the mirrors. I am allowed to remove the side mirrors based on the allowance to use any mirror, but is there anything that allows me to remove the associated wiring (from the harness) since there is no specific allowance to remove the mirror "in its entirety" or "including all associated wiring".?

Be nice and enjoy.

Rory

[itracer]

"d. Any interior or exterior mirrors may be used." implies that the exterior mirrors can be removed and/or replaced. So any wiring related to those mirrors can be removed as well.

Mine is one opinion, but that is how I read the rule.

[Greg Amy]

Commonly done (I did it on all my IT cars). I suggest it's compliant.

[Chip42]

yeah you can remove the wiring to any component that was optional, dealer isntalled etc... and can also remove any wire to a component not required to be kept, like the mirrors, dome light, cig lighter...

stuff that you cannot remove, most notably engine sensors, you can't remove the wires EVEN THOUGH you are allowed to replace them with a custom engine harness. In these cases, the stock engine harness is reducndant but must be kept. there's logic in that rule, I promise.

[shwah]

If there is logic in there, we would not need to trust that it exists.

IMO there is no reason to require retention of wires that serve no function on a legal car, but that is not how the rules are written.

As noted there is some wiring that can be removed and other that cannot. The under hood stuff that I have no problem removing is the ones related solely to gauges, or any other specifically allowed stuff.

[JohnW8]

I'm glad I didn't strip out my excess wiring, I needed it to make the new weight
for the Miata in ITA.

[dickita15]

yeah you can remove the wiring to any component that was optional, dealer isntalled etc... and can also remove any wire to a component not required to be kept, like the mirrors, dome light, cig lighter...

stuff that you cannot remove, most notably engine sensors, you can't remove the wires EVEN THOUGH you are allowed to replace them with a custom engine harness. In these cases, the stock engine harness is reducndant but must be kept. there's logic in that rule, I promise.
You can make an argument that seeing ignition is unrestricted those wires can be removed and replaced and seeing emission can be removed wires for that purpose may be removed.
d. Exhaust emission control air pumps, associated lines, nozzles, and electrical/mechanical EGR devices may be removed.
e. Any ignition system which utilizes the original distributor for spark timing and distribution is permitted.
Besides:
9.1.3.1.a.7. Wires and connectors in the engine wiring harness may be modified or replaced.

[Chip42]

there are a lot of allowances that overide others, but if you "remove" a sensor, say the AFM, from the ECU (maintaining that required element in the intake) then the wiring you added for the allowed MAP does not "replace" that of the AFM. that AFM wiring has to be kept. ditto any other engine sensor that no rule makes you use functionally, but that you must maintain on the car.

the logic is that there are a lot of combinations and there was no desire to make custom and bespoke engine harnesses overly beneficial, and there's always the risk of establishing a precedent or modifying the slope of the trajectory of the rules toward more allowances. that rule was written as a way to simplify the modern driver comfort wiring loom mess and make it a bit easier to keep an older car legal.

[Ron Earp]

You can remove the mirrors and wiring. I, like the others, believe it legal. When building the Mustangs we removed any optional wiring on a Mustang such as power windows, seats, anti-theft, ABS, cruise control, radio, subwoofers, and so on. The wiring really does add up - here is 7.5 lbs worth from just the interior of the car.

http://www.gt40s.com/images/Mustang/wires.jpg

All told we removed about 13 to 15 lbs of wiring from the harnesses of the car. It was a royal pain as we didn't cut the wire, we actually removed the wire from the connectors taking the pin and all. Nice, clean, and very OEM in appearance and function.

[dickita15]

. It was a royal pain as we didn't cut the wire, we actually removed the wire from the connectors taking the pin and all. Nice, clean, and very OEM in appearance and function.


+1
When I built the current IT7 car I spent over 20 hours with the harness on the bench. Check the manual, unwrap the harness, remove wire, rewrap harness, and this is with a harness not much more complicated than a Model T.

[Ron Earp]

It was a royal pain. But as you already know, if you want it done right that is the way it should be done. When you're dealing with a weight challenged car you can't cut corners on prep. Everything must be closely examined from the type of muffler clamp you use to how thick the header flange is to the construction of the intake pipe.

If I'm not mistaken you proved the prep point by getting the 1st generation RX7 down to ITA weight, a task most consider impossible.

[CRallo]

He did! And with room to spare, depending on driver. The best part is, as he tells it, is that he was trying to prove that it couldn't be done!
.
The only problem is the early FB's were fugly in the rear :p BUT, they are supposedly lighter...


It was a royal pain. But as you already know, if you want it done right that is the way it should be done. When you're dealing with a weight challenged car you can't cut corners on prep. Everything must be closely examined from the type of muffler clamp you use to how thick the header flange is to the construction of the intake pipe.

If I'm not mistaken you proved the prep point by getting the 1st generation RX7 down to ITA weight, a task most consider impossible.

[shwah]

As a reference point to those scared of outrageous weight reduction by removing unused wiring from a race car - the current world challenge VW Jetta loses 17# of wiring when all unnecessary wires are removed from the car.

Still looking for the hidden benefit that anyone would gain by removing copper and insulation that does not do anything functional in a legal car...

Can you expand on this Chip?

[Chip42]

it's based on a desire to not make a custom harness de facto required to run at the top. personally, I don't think it accomplishes that, but retention of the stock engine harness is a rule, and this allowance to remove wires for electrical stuff you are allowed to remove has been added. we put the line in there to make it clear that removing redundant wiring was not allowed. it's just an attempt to limit the further creep from the new rule. nothing deeper than that.

[DoubleXL240Z]

I think they are worried that people will use those wires as an antenna for a wireless engine management system!!!
hahahaha!!!

[shwah]

Not sure I see how something that does not change any function on the car can possibly become a defacto requirement. Nor how removing redundant wiring is creep, especially against the backdrop of just adding a rule to remove wiper washers/bottles/etc.

While it's not a huge deal, I sometimes have a hard time dropping things that don't make sense to me (and I think we are all like that to some degree based on the discussions that thrive the strongest here, especially over the winter).

I do appreciate the allowance that was given.