Always seems to be something fix or upgrade. Neverending. But, we all like that right?

So, I wanted to move the battery into the trunk, and at the same time, use a AGM battery (26lbs vs 36lbs).

Well, here it is mounted using the billet mount. The PO cut a hole in the trunk for starter access, so, I decided to put this to use. (Yes, I do plan to clean up the hole.)

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Someone else did something simliar, and I had asked about the wires that normaly attach to the positive post. So, I used a battery bulkhead connector and attached the wires using that. You can see it in this photo next to the petronix.

Here's the post unmounted.

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Inside engine bay.

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More in next post....

(Still have to fix that big hole in the firewall, put new bars and shocks in the front, and fix an engine miss. <sigh> Don't think I am going to make the AX this weekend...)

-- brett

And here's a picture of the bulkhead inside the trunk and the wiring.

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-- brett

Correct me if I'm wrong, but don't you want the weight between the axles and as low as possible?

The Cap'n

Yes. I wanted the battery out of the engine compartment. I was aware of the placement, and just picked a good place to mount. Ideally, it should be moved forward more. (And no, I don't want to put it in the front trunk.)

The next step after this, is to corner balance the car. I still plan to make adjustments, such as moving the battery around if need be.

Thanks for the comment. (Good point!)

-- brett

brett,

914's are tail heavy... even stock... especially as race cars.
to be more balanced, you want to move weight forward from stock
batteries in the cockpit or front trunk are really a step in the right direction when it comes to optimum corner balancing.

Agreed. I had a choice of here or in the passenger compartment. But, I still don't like long leads from the battery to the starter. Electrical problems are not fun. I used to have a Datsun 510 for Ax, and had moved the battery to the trunk. It worked, but it was one very long cable. I remember getting a 2 gauge cable to keep the resistance down. That of course, added weight.

I will play with the location a little, but I just choose a good place that was easy to install as the place to put it.

Thanks for the advice.

--brett

Put it here.

You should put it here.

It just occurred to me that you've placed the battery directly above the muffler, one of the hottest places in the car. Even more "not good" than I previously thought. As for the cable issue, welding shops have a nice selection of more-cable-than-you'll-ever-need, as well as a choice of crimped on ends that will suit your needs perfectly. Electrical issues involving battery to starter issues then become the last thing you'll ever have to think about.

The Cap'n

Bring some weight to the front, already plenty in the rear. Bring balance to the force you will.

It's been 5 years since I stuck this here. @11lbs you can put it where ever you want. I could have put it in the front trunk but the cabling would weigh as much as the battery. This makes for very convenient runs for the various wires....like the main feed for the MSD & starter/charging. Bout ready for a new one, me thinks.

Part of what I am working toward is a ligther car, and simplification. Short wires = both.

I do like your placement better than mine, and that is an easy fix.

As far as heat from the muffler, probably still less than being in the engine bay. I can place a probe and measure it.

-- brett

That car is so cool, it doesn't matter where the battery goes.

Put it on the pasenger side floor. That is as low as you can go and keeps the cables short and counters the weight of the driver. Needless to say that is where mine is......

With the type of battery you have you could just put it lower on the rail as well. Much better for balancing. I was going to relocate mine behind the passenger seat but I never got around to it.

I almost bought the 680 instead of the 925, as I wasn't sure if it would crank the motor over. Obviously, I should have got the 680.

-- brett

And I bet the 680 would fit. The 925 was too big.



Maybe I should move this battery to the street car and get the 680 for this car.

-- brett

With the lid on, it gets REALLY hot, much hotter than the original location. The Cap'n

with the Cap'n. I mistakenly left a Tyvek car cover in the trunk for a track event, and areas touching the trunk floor melted.

My battery is mounted in the front trunk like Elliot's above, only difference is I use a small battery similar to this to save weight.



I'm using the welding cable approach as the Cap'n suggested and have no issues what-so-ever with this setup. The cable adds weight, but it is as low as you can get and in the middle of the car.

Hope this info helps. Just trying to share a successful setup and lessons learned with the car cover in the trunk.

Elliot, where did you run the battery cable?

Any problems/issues with running the cable underneath the car?

-- Rob

I am moving the battery to the front too. What gauge wire are you using and are you running it in the longs or really under the car?

Jim

I guess I'm just a party-pooper. I thought the factory did a pretty damn good job placing the battery. It partially offsets the drivers weight and it's almost centered in the middle of the car. It doesn't suck up any trunk space and wiring is a piece of cake. I can't for the life of me figure why the big urge to move it especially with the light weight, leak resistant batteries available today.

Yes, the hell holes are a direct result from batteries but that issue is almost totally resolved with today's batteries

Can anyone honestly say they moved a specific battery to a trunk and got a reduced time in a race or noticeably better performance?

I kept things simple and put a PC680 in the stock location. I'd already shifted at least that much weight towards the front with a giant oil cooler and race fuel pump and filter in the front trunk.

the move show's up on a set of scales.
I don't know that consecutive laps have ever been run with both set ups... on the same day, same place, same weather, same car....

but it will show up on scales

and racing is a game of very small improvements
(the factory built mag cases over earlier aluminum ones for a savings of less than 20lbs and to help the corner balance of a tail heavy car)
brant

Brant, honestly I can't argue that response as it's certainly true and accurate....but I can eat a Big Mac and it shows on a scale....

Point taken....I could better understand it if it was on a fully stripped race only car where the pounds moved around are a higher percentage of actual car weight but most of the moves I see are far from that. The corner balance on the scales may look better but it depends where the weight is located to truly make a difference and the point I'm trying to make. It just seems like moving weight further out, especially to the rear would tilt the scales the wrong way.....

So maybe I need to illuminate my situation a little better. The car is a stock 1973 2.0 L I do not intend to race. I have had to remove the battery support as I discovered it was held on by less that a hope and a prayer after battery acid had worked on it many years. The surrounding metal is pretty good, and I plan to treat it with Por 15. My dilema is I don't know how to weld and I want to get the car back on the road for the summer, and by fall I hope to either have found someone to weld the new stock support into place or have learned to weld enough to do it myself. I am not doubting or debating anyone's experience or wisdom. I am just trying to get the car running. With that said, can the battery mount support be welded into place with the engine in place? I expect to need to move the fuel lines during the process. Is there anything else I should be concerned with?

Thanks,

Jim

I've never measured the temps but I rather doubt the rear trunk gets any hotter than the engine room......OK, so it's non-typical.

The PC680 probably weighs about the same as the stock battery mount and it & the mount are now out of the way. The battery has plenty of poop to turn over the 10.5:1 motor.....I do think it is getting tired after 5-6 years of service tho it's never failed to start the car.

We've gotten the car down to 1700 pounds. The battery was just part of that.
That said, we have to ballast up about 85 pounds to run XP. Over 300 for FP.

Okay this is my first of many posts/replys as I have just become the owner of a barn find. Here is what they did to the battery some years ago. it is a stainless steel box (no drain) mounted down into the trunk as shown. The routing of the positive side was enough to make me disconnect the battery as soon as possible. God only knows if the sheet metal has warn through the insulation where it goes through the body. Anyway, you comments are welcome as to pros cons or what are you thinking. The car will be used for street.

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