sm

I was wondering if anybody has moved the battery from the engine bay to the rear cubbies. If so, what did you do? Any info or pictures would be appreciated!

Thanks,

sm

Ganja Porsche

This task could be accomplished rather easily. I'm pretty positive it can be done, running the wires could be done in the manner people run the lines of their NoS tanks... Just curious, why are you wanting to do this?

Nicolas

Hello
This mod was actually done by the factory as Great Britain car have their battery relocated to the rear....
I am also looking for some pictures so if any english owner read this and can provide the board with some pictures we will be very gratefull.
Why do this ?
1/ better weight ratio Fr/rr
2/ Personnaly I need the space of the battery to locate some advanced ignition stuff...

Nicolas

Danno

Summit Racing has a battery-relocation kit for about $50. Includes heavy-duty long cables and a battery box.

If you ever start stripping out your car to reduce weight, you'll notice that most of the parts you're removing are from the rear of the car (spare-tire, rear-seats, rear-wiper/hatch, carpeting/sound-insulation). Given the stock 951's weight dist. of 51/49 f/r (60lbs more in front), you may actually end up with a 55/45 f/r distribution (280lbs diff). So relocating the battery will help restore the balance.

Martin

I have done this, I used a marine mounting box and welding cable, to connect the cable to the old connection point I used a gold plated audio connector, I grounded the battery in the rear. I located it on the right side as the sunroof is in the left.

sm

Thanks for the tips...

I'm thinking of relocating the battery because the stock location in the front is allowing the elements to corrode the terminals. That's my main reason for doing it, and if I get better weight dist., even better!

Martin, where did you run the cables and did you have to drill through the firewall?

Thanks again,
sm

Martin

The cable is run through the right rear wheel arch, it comes through a hole just below the seat belt, I put extra insulation around it where it goes through steel, it then ran under the plastic inner door sill then up and over the pedals (RHD) and across to a rubber grommet that was beside the wiper motor in the front tray area.
It is held in place with lots of cable ties.

hybrid_944

I am about to do the same thing to my 88-944. but with these cars I would have to disagree with mounting it in the right rear cubby. Mostly because, the fuel tank has a large sump in the right rear of the vehicle. Making the extra weight of the batt, with the weight of the extra fuel too much for a ‘50/50 left/right rear weight ratio’ (say that 5 times fast). In my car the right half of the gas tank has a sump that holds about 8 more gallons then the left. At about 6lbs per gal. You’re looking at about 48 lbs, of gasoline alone.

I think best place for the battery is in the left rear. Where it can help balance out the weight of the extra gasoline. My Brother's best friend has a set of racing scales. 1 for each tire. So after my cage is installed I am going to set it up and see where all of the weight is. Then I will start moving Mass around. But, until then I’m merely guessing on what I've noticed from under the car. Oh To ad to my weight situation, I’ve removed the spare tire bin. –20ish lbs of excess metal.

mike

Danno

Here are my corner-weights from the last time I had it done:

Without driver:

L | R

795 | 778 F

____+_______

723 | 758 R



With driver:

L | R

859 | 789 F

+64 | +22

____+_______

794 | 793 R

+71 | +35



As you can see, most of the weight added with the driver goes to the left-rear of the car. The guy that did the corner balance mis-understood my instructions to even out the "cross-car balance". You don't necessarily want even left/right balances because that won't necessarily mean the most even loading of the tires. See my write-up on corner-balancing here:

Corner Weights (RS/RSR) ???

Tom

One other good reason for locating in the left is that the overflow from the fuel filler drains into the right rear cubby.

sm

Tom:

I didn't realize that fuel gets drained into the right cubby. Guess I should keep that cubby empty, huh?

sm

Tom

There should be a hose that goes down to the drain hole but my experience has been that it moves around some. Also fuel only goes down there if you spill while filling or if the gas cap should be loose so it's not a big problem but it can happen and a spark at the wrong time could lead to a little more excitement than we'd like! I've neverhad trouble with stuff in there but I try to avoid things that are absorbant. Also when putting things in those compartments remember there is the possibility of denting the outer skin if the car (from the inside).

hybrid_944

The weight that you had stated. what are the modifications that you have compleated. also was the gas tank full 1/2 or empty????

mike

Danno

The weights I listed was with 1/2 a tank since this would be the average. I removed the rear seat backs, and installed a rollbar, so the 3055lb total weight is a little heavier than curb weight of stock '86 951. But I didn't take out the spare tire, jack, tools and carpeting like I usually do when I'm at the track. So I guess it's time for another corner-balancing session (this time I'll give clearer instructions).

BTW, short of putting lead ballast under the passenger seat, you're never going to be able to get 50/50 L/R balance with the driver in place. What you really want is the same F/R distribution on both sides (or else you'll understeer in right turns and oversteer in left turns or vice-versa). In my case with the driver in the seat, I have a 52/48 F/R distribution on the left side of the car, while it's 50/50 on the right side. So raising the right-front (adding weight) a little should even it out.

Martin

The fuel drain connects to a hose that exits the bottom of the cubby hole with the sunroof drain tubes, there should never ever be any fuel in the cabin area.