John H

Anyone here fabbed a tied down system for the optima battery? I have no spare tire in the race car and, as I found out Sunday, a bumpy track can dislodge the battery from it's normal resting place. Someone said they got an adapter from Performance Products, but i looked and don't see anything there for the 993. Any suggestions would be appreciated. Pics are always great. TIA

Don Plumley

Here's my solution , though for an Oddessy battery, would work for an Optima.

ceboyd

I have the optima redtop and the factory tiedown worked just fine (what is wrong with the factory tie down?)

BobbyT

Ditto what ceboyd said...

agentpennypacker

I bought some sheet metal at home depot and bent it around the batter (lying down). Wasn't too hard - I'll take some pics this weekend...

John H

The problem is that the factory clamp doesn't get a real bite on the bottom lip of the Optima due to the battery's design. If you have a spare tire, it's not that big of a deal but without, the battery is free to roam ones it works loose from the clamp. Mine bounced around until the ground cable came off. Then the battery was free to smash the ABS relay cover and pull the positive cable around with it. I never thought it would be a problem either but the track was bumpy (not rough but undulating due to settling of the soil under the track). The car bounced in several spots. Anyway, it was enough to cause the battery to work loose from the clamp and end my day early. If it had been an enduro, I could've "fixed it" and got back out in plenty of time.

ppressle

I recently saw an Optima installed with the factory battery clamp in a 993. The back side lip of the battery was not captured under the lip in the wall of the trunk. This allowed the battery to simply lift up and come loose. Not good.

I installed a spacer behind it to match the thickness (away from the trunk) of the lip in the body. This is better, but not great.

I think that what is needed is a way to make the lip in the trunk body another 1/2 higher. Possibly an s shaped piece which could be installed in the existing lip to provide a higher lip for the battery.

The other alternative is to do what Don P has done and build something serious.

(ooops. Had the wrong battery. Changed it to the correct one.)

bgiere

Hi John, I had thought it was PP but i now remeber it was AJ USA that had it....also JEGS has some very nice aluminum holders...they are pricey though...i think the AJ holder was 65ish...good to see you at Beaverun!!

Ray Calvo

Have an Optima 75/35 battery in my 993; have used the stock bottom lip mounts with no trouble.

And what the heck are you doing running w/o a spare tire? It's added nose weight for better front/rear weight distribution and if you're in an "incident" it's added front crush resistance.

John H

For NASA GTS Challenge events, I take it out to shed as much weight as possible. The 993 is one of the pigs in the class given the HP to weight ratio works out much closer to the slower end of the GTS3 range than the top end of the range.

Besides, it's alot of fun taking out the spare tire, door panels, ballast (84 lbs) and passenger seat after a PCA event and putting them back in again after a NASA event.

BTW, I have the yellow top which, as you can see is a little different than a regular battery

ceboyd

i thought the yellowtop is DEEPCYCLE for marine use?

John H

It is a deep cycle. When I forgot to switch off the cutoff when I stored the car, the transponder, clock etc would drain the regular battery between events. Then, we developed a much quicker draw in the ac wiring that would drain the battery overnight. That has been fixed by pulling some fuses but I went ahead and bought a deep cycle anyway. It was stated that alot of the big car stereo guys/gals use the yellow top.

Steve Nagata

Marine Optima batteries are "blue" tops.

BTW that Yellow batter might not have enough CCA/CA for your 993. You'll need a bigger one (then you can use the factory battery tie down)

John H

Here's s pic for the record