Dan Cobb

What are others doing to attach an Optima battery in the 911?
I see performance products has an adapter for $35 What does it do?
Did you have to get a longer ground strap? (Mine seems to be stretched a bit much)
Is a photo of this adapter available anywhere?
I don't want to use a 2x4 and a bungee cord, but $35 just to mount the battery!?
Geez
+++

jaydubya

The Performance Products mount is a stainless steel plate, just slightly larger than the footprint of the optima battery, with four pieces of allthread that go through the two pairs of holes on the sides of the battery. There are locknuts supplied for the threaded rods. The lip of the plate fits under the stock hold-down clamp, which attaches to the car with a socket-head cap screw.

I'm sure you could make one, but for $35 I'd just buy their little kit. Seems to work well. Only issue is that I couldn't get a wrench on the locknuts since they are so close to the side of the battery.

Capt. Carrera

Here is how I mounted mine. I bought a large sturdy plastic cutting board. (It's almost exactly the same thickness as the battery bracket in the car.) I trimmed it down to the same footprint as the regular battery. Then I drilled and counter-sunk four holes in it that line up with the holes on the sides of the Optima. By passing some stainless machine screws up from the bottom of the board, I bolted the battery to the board. (The counter-sunk holes allow the heads to recess into the board.) Then I simply slid the assembly into the car and secured it in place using the OEM brackets.

earlyapex

Rennline Design makes a nice battery relocation kit. The 680 kit is going into my car this month.

Dan Cobb

That is a great looking relocation kit, unfortunately some of us are happy to have the AC parts that came with the car. I'll probably either buy the kit or use a piece of plastic (ABS, etc.) like Capt. Carrera.
Thanks for the insights.

Capt. Carrera

Here is what it will look like when you're done.

Dan Cobb

Exactly what I was expecting. Did you also have to replace the ground wire? Yours does not appear to be the same as mine in style or length. Mine is the flat, woven braid rather than the insulated cable.
I hate the easy stuff, it always turns into something more difficult.

BTW, I was recently told that these batteries have a negative impact on the life expectancy of a porsche alternator because they charge more slowly than a standard battery, plcing a larger load on the alternator for a longer period of time.
Any negative effects since you installed yours?
+++

Capt. Carrera

The cable in my Carrera is what was there when I bought the car. If you do need to change it, it's easy to do and not much money.

I have not had the battery in long enough to comment on alternator life. Come to think of it, if the alternator does die, I wouldn't know how to scientifically say age or load did it in. The last battery had to place a pretty good load on the alternator. It was huge. The PO installed it about five years ago.

I can say the front pan should last much longer with an AGM battery.

Dan Cobb

I had very similar thoughts; it is far easier/cheaper to rebuild/replace the alternator once in awhile than it is to replace the front pan once.
+++