I am not running an alternator on my car, so I am going to run two batteries. I have already made the battery hold downs, but I just need a box to put them in. Is there any way to put them in a NHRA approved box, without spending $180 on just the battery boxes? The batteries are small enough that if I ran a piece of metal across the orange pieces in the picture, they would clear with plenty of room. Would that be considered a "firewall"?

 

Fabricate a sealed cover to enclose that area where the batteries are. Don't forget, you'll also need a master switch mounted at the rear.

It's always better to run an alternator. Ignition etc works much better with a good voltage source. A second battery is a lot heavier than an alternator.

 

What classifies it as "sealed"? I mocked this up, but I'm not sure how tech would look at it. It would obviously be made of .032 aluminum or .024 steel. Then on the ends, I would have either studs running through and pins, or just dzus fasteners. Probably all the way around the panel, I would have weatherstripping on it. I already have the charging lugs and master switch mounted.

 

Considering the Taylor battery box in the back of my car is a simple thin aluminum box with a removable top and bottom, the classification of "sealed" is up to the tech inspector. The Taylor box is not air tight and it passes the NHRA requirement. I would say as long as there are no large gaps around the edges, it will probably pass. Many racers complain about required a sealed box while using a sealed battery such as an Optima that can be installed in any position but NHRA gets sponsorship by creating rules requiring specific types of products.

http://www.taylorvertex.com/battery/boxes/

Many, many years ago before I did my back half, I ran a single battery in that same position with a simple piece of aluminum covering the opening. Never had an issue but I was also running in a much slower class at the time.

 

what you have will work fine and pass tech. make sure you drill a hole in the bottom of the well to vent gasses.

NHRA does not get sponsorships by requiring certain parts be used.

also, run an alternator. this is 2020. most alternators take very little, if any HP to run, and most electronics are happier on 13.5+ volts versus 11.5-12 (which is what you end up with having no alternator)

 

I made a baox in the back out of aluminum sheets and aluminum angle and riverted it together. Hinged the top and keep it closed with Dzus fasteners. My battery is on the rt. and my fuel cell is in that well also on the left. A friend of mine has a good saying about 2 batteries. The only thing worse than a dead battery is 2 dead batteries. I use one group 65 standard battery and an alternator. I have seen many run 1 battery and no alternator and just charge between rounds.

 

The only reason to not run an alternator is when it's physically impossible to mount one. Even on my engine, with the front motor plate in the way I had nowhere to normally mount an alternator. I have a belt driven fuel pump and vacuum pump. An electric water pump limits where things can be mounted as there is no water pump pulley to change the direction of the belt. I ended up mounting the alternator backwards to get it to work. The alternator doesn't care which direction it spins.