I was driving around Laguna Seca and heard a pop, smelled something burning, and some of my gauges power cycled. The smell went away immediately and I drove back into the pits. I figured I had messed up some wiring after bottoming out the car at the corkscrew. Doesn't look like the problem was underneath the car, though:

I wonder where the rest of the terminal went.


Apparently I can spot weld and drive my car at the same time.






Unfortunately, my battery mount didn't hold up for two track days. The battery was sliding around putting strain on the wiring which must have caused the explosion.

Now I need to figure out why there are sparks rolling in from under the passenger seat every time I brake.

 

Ooly chit!

 

Looks like the battery rotated around the ground wire attachment after the hold down broke and the positive lead welded itself to the deck lid and melted the terminal. It then managed to rotate back into its original position after I brought the car in. This also explains why under braking the passenger said there were sparks coming in from underneath the seat.

Time to get a lighter battery, a proper cutoff, and make sure the mount is secure.

 

Lmk if you need a better mounting solution fabricated.

 

In what way did the hold down fail? I have the same battery and the OEM hold down bracket, I've never trusted it very much, but it also has never failed.

 

There's a metal angled bracket on both sides that clips into the piece that goes across the battery to hold it down. Not sure if this is stock on a 95, but my 97 had something different. The battery is really heavy (~35 lbs) and it bent one of the angled brackets to where it broke loose and gave enough play to let the other side come loose. Then the battery was free to slide out towards the front/center of the car. Popping the trunk is now on my list of things to do after every session.

 

Another thing to consider...insulate the battery terminals. A rubber boot is good, wrapping the terminal in self-fusing silicone tape is better. Highly recommended for the back of kill switches and battery posts.

Self-fusing silicone tape is awesome. A little can go a long way, as it can stretch 2-4x its length. The tape seals tight and withstands a reasonable amount of pressure, heat, and voltage. A name brand is "Rescue Tape", but there are several generic types. Bonds to itself - there is no adhesive, and doesn't stick to other surfaces.

http://www.rescuetape.com/

 

It's tempting to print out this thread to show people why we fail cars in tech with exposed battery terminals at SCCA autocrosses.

 

Cool story, bro!

I think you should leave the bolt welded to the deck lid. Adds character!

Seriously, though. Definitely a good lesson in why many safety stewards are ---- about the rules and proper/adequate equipment.

 

Wow, that is one hell of an eye opener. I am glad you and your car (for the most part) are fine. It could have been way worse.

 

I had this exact same thing happen to my NA at Laguna Seca about 5-6 years ago on a fun run. It managed to burn a small chunk of steel out of the decklid hinge, quite entertaining. I wish I had taken some pictures.

Keep an eye on your alternator, it just did A LOT of work... mine started doing goofy **** and I replaced it about 2 weeks later.

Glad everything turned out OK though!

 

Thats badass man. I'd definitely leave the bolt there! lol

Makes me want to take care of my battery mount. Since installing the bigger yellow top battery its been free balling back there. The battery tie down wasn't long enough and I never did anything about it. Looks like I better get on that.