snerd

I have a question for all the people that removed extra stuff from their interior (stereo, speakers, etc). What did you do with the wiring that went to the components? Did you leave it in place and just tape it off, or did you remove it? If you removed it, did you just cut it off before the CPU/ECU, or did you completely remove it from the harness with a pin removal tool?

Silkworm

Depends on the rules...

in IT, you have to keep the damn wiring.

In E-Production, I'd probably yank the whole mess and rewire the whole car

PaulC

Travis R

I've removed all the wiring from my SoloII project car. The weight was surprising. If this is for a race car, you definitely need to see what the rules allow. If this is for a street car that you just want to shave some weight from, I'd just cut the wire as close as possible to the harness. Removing individual wires from the harness would be very time consuming.
Good luck

snerd

Thanks for the info. I hadn't even though about rules including wiring for accessories. I'll have to check in to what will be allowed for the class that I'll be in (once I figure out which class to build for ). I wanted to try for a stock or a mild mod class, but I had to remove most of the interior since the carpet and seats were not salvageable. I'm pretty sure I'll be bumped to prepared.

The reason this even came up is that the car I bought had a buch of extra cool stuff (active suspension, ABS, etc.) that had been removed by a previous owner. It has a huge wiring harness running to the rear of the car, but the only things that are really back there are the rear lights and the rear wiper motor. I really just wanted to simplify the wiring in case I had to troubleshoot something.

Samps

fuel pump is in the back also.

How much would you guys estimate that all the wiring in the car weighs?

sbaker25

I don't think it's as much as you have been lead to believe. I removed the entire interior wiring harness as one piece and I'd say that it weighs less than 10 pounds. And less than 10 pounds for the wiring harnesses under the hood.

The only reason I removed mine was that I thought it would make more sense to sell the intact interior harness and rewire than to hack up a perfectly good harness to support only the fuel pump and the brake lights.

snerd

What is invloved in making your own harness?

I know that I will need to get wiring to run to the accessories. Where would I get the plug that goes in to the CPU? I would like to keep my old harness intact, so would I have to get a donor harness from a junked car (for the CPU plugs)? Would I need a special tool for crimping the wires in to the plug if I was able to purchase a new plug?

stinkfist

I just happen to have my complete interior harness bundled up in my garage. It's from a 1984 GSL. I just weighed it at 16lbs. This is the interior only. I don't have the engine bay harness laying around but IIRC it was around 10 lbs. It's not substantial but every little bit helps.

Mike

FPrep2ndGenRX7

Mine weighed about 24#. It was an 87TII harness with electric windows and a sunroof. My harness now weighs about 5# including the wire, fuse block, distribution block and relays.

Samps

20 pounds of wiring! Sounds like a winter project. Remove all excess wiring and the sound reducing crap. Maybe another 50 pounds lighter.

How bad do you think some of us have thrown off our evenly distributed weight by removing so much stuff from the car? My engine bay is bare, my trunk (vert) is bare with the battery, And I have taken out just about everything I could find that wasn't necessary to remain stock looking or keep street function (heater). If we started with 50/50 and we removed the AC and the PS then we have already just ruined that balance. Anybody have something to say about this? I also put the battery in the trunk; which makes the balance even worse yet. How can you adjust the new reduced weight back to a good balance without actually adding any weight? I don't want the battery back up front; moving it to the back really lightened up the steering effort after the manual rack was installed. Is it possible that a little more bias in weight towards the back could actually be a good thing? I mean porsches seem to do a pretty good job with their weight.

Silkworm

Samps,

This is why, EVERY time someone starts harping on the V8 swap I have to laugh..

Honestly, even 50lbs of battery back there plus 50 lbs of AC/PS removal up front might shift the weight balance rearward 2%.. Maybe. Plenty of cars out there handle JUST fine 60/40, 48/52 isn't going to be a big issue.

All,
As for removing the wiring harness, IMHO, it's more trouble than it's worth unless you're willing to rewire everything. You could go through and unwrap all the harnesses and snip out the wires you don't need, only to find wires you DID need and snipped, and frantically post questions on wiring harnesses and diagrams..

Or you could go on a diet
Ok ok, or remove the interior plastic/Sunroof
Remove the AAS computer and spare tire
Remove the interior tar
Go under the car and remove any undercoating
Strip the car and repaint it with a single layer of paint
Install an aluminum hood, lightweight battery, remove all smog equipment
Install a thinwall single exit exhaust with uncoated header
Install an aluminum radiator
rip out the dash and gut it or better yet, take it and throw it away and install a minimal aluminum dash..
Cut out the inner door skins and remove the windows
Install a lightweight aluminum seat
etc etc..

Plenty of other things that aren't nearly as tedious as trying to trace back unnecessary wiring..

PaulC

sbaker25

I just have to say that I think that removing the factory wiring harness is far easier than retaining it in a true race car. The factory wiring harness would be ridiculous to handle 7 or 8 circuits and it would require a bunch of unecessary wiring diagram inspection to figure out how to fit only the parts together that you still need without causing any other problems. For example, I will have a fan switch rather than a computer controlled fan system that works with 4 relays.

That said, if a person was in this position, they probably would not consider cutting up the factory harness to simplify it. It would be far easier to just wire from scratch.

As for weight balance, I see no reason that a person should disregard this consideration. I don't know of any cars that are a 60/40 balance that handle great. "just fine" is what you said, but that doesn't mean much. fore/aft balance is an important consideration and it doesn't need to be ignored. It is true that, for most people here, it's going to make an immeasureable difference because we don't have the skill to drive consistently enough to attribute any difference in times to balance. So, I would agree that weight shifts are not going to be a big issue, but the people who win pay attention to these details. Unfortunately, that's not to say that all those who pay attention to the details win .

However, I would also say that I wouldn't worry about moving weight rearward. There seems to be a big misconception that 50/50 is the absolute ideal. That is not the case. I expect that 48/52 is superior to 50/50 in this car. Samps, if I were you, with respect to moving the battery to the trunk, I'd be more concerned about the battery's height than its rear location.

Silkworm

WRX stock is 62/38 IIRC..

I'd say they do alright in the handling department (not stellar, but not too bad)

I agree, if you pay attention to the details, you can win, OTOH, people spend FAR too much time fussing over getting a perfect 50/50 when it's not necessary and you can be spending time working on more meaningful activites (like lambasting on a BBS like I'm doing right now)



PaulC

Samps

Thanks for the info. Glad to see there can still be some civilized debates on this forum.

I could see another issue with snipping the stock harness. When you start cutting wires they all need to be capped in some way or there will be a good chance that one could ground out. I had this happen when I put in an aftermarket radio. I just cut the whole bunch of wires to the stock amplifier (in a vert) and one of the wires I cut was not cut perfectly and a little strand of wire was sticking out. Needless to say it grounded out, and shut down the radio, causing me to spend an entire weekend trying to figure out what happened. Electrical troubles seem to be the hardest to conquer. Maybe this is one of those things that's just not worth the trouble. But the sound crap is still coming out!

Travis R

I plan on doing all of those things.. and more. Fiberglass hood and fenders, 1/8" lexan windows, and a fuel cell.
The weight distribution is more than just fore and aft, it's also up and down, and side to side. If you remove all unnecessary items and you need to add weight to get the (fore/aft) balance back, you can add it to the bottom side of the car lowering your center of gravity. A lower center of gravity means less lean in the turns. You can also add it more towards the middle of the car (front to back). This will decrease your polar moment of inertia. Remeber physics class? That means the front tires won't have to work as hard to make the car turn. Fixing the side to side weight distribution means that the car will turn just as good one direction as it does the other. But like someone else said there aren't a whole lot of people that will be able to tell the difference. Maybe I'm one of those people, maybe not. But I've got plenty of time to find out.
I was going to guess that wiring harness weighed about 20lbs. If you want to remove the whole thing just use a set of big bolt cutters and hack the harness into two pieces where it passes through the firewall. Then after you unplug the components you can just throw that section of the harness away, rather than trying to feed the connectors though the little holes in the firewall.
Good luck

FPrep2ndGenRX7

I've only got two circuits on my car. One to get power to the coils and one for the fuel pump. Ofcourse I have no head lights in the car and I'm not required to have brakes lights and there are no computers or fans to run. There is room to grow but its not needed right now.

Samps

Mechanical guages?

Do you remove the "low fluid" sensors?

And what about the gas cap cover? Do you leave that with the cable attached or modify it somehow?

FPrep2ndGenRX7

I have mechanical guages and the gas cap cover is still in place. The release cables are still working. If you remove the cable you can still release the cover from inside the car and use a key for the rear hatch. I'll probably remove them now having said that.

TeamWireRacing

[QUOTE]Originally posted by Travis R
The weight distribution is more than just fore and aft, it's also up and down, and side to side.

Actually, the cross weights that you didn't mention are the most important ones to match. My old race car would make weight but had bad numbers on the scales. Really hard to get the crosses right and keep the right heights in check. Adding weight in the right areas made the car heavier than it needed to be, but was still faster on the track due to the better chassis balance.

Fixing the side to side weight distribution means that the car will turn just as good one direction as it does the other.

As mentioned, the cross weights are actually more important than the side-to-side weights when searching for that elusive "balance". Dynamic weight changes in a car tend to move about a theoretical "X" in the chassis when viewed from above. Getting the static cross weights equal (by % number) means that each diagonal is carrying an equal percentage of weight compared to the other.

But like someone else said there aren't a whole lot of people that will be able to tell the difference. Maybe I'm one of those people, maybe not. But I've got plenty of time to find out.

Don't forget to put that set of scales on your Christmas list this year. Without adjustable coilovers and a set of scales, this whole conversation becomes a guessing game with no means to quantify the results of any changes you make. That's why the pros do this stuff. Not only because they need to to be competitive, but because they can since they have the proper tools.

sbaker25

This thread belongs in the Race Tech forum more than it belongs here and the person that moved it should reconsider.

This is the second time in recent weeks that a discussion has been moved out of the Race Tech forum to a less appropriate place. I respectfully submit to the moderator(s) that the goal of moderating a forum is not to move threads out of your domain.

This thread belongs in the interior forum no more than a discussion about installing a fuel cell in the cabin or installing a cage.... IMO.

Silkworm

This belongs in race car tech!???????????? WTF is going on?