Battery Tie-Down Pics?


Since the right rear clip of my car was smashed and replaced, I need to create a new battery hold-down / tie-down. My thought was to do it with threaded rod through the bottom of the car and a piece of square aluminum across the top. I got the left side rod in place, and then found that there wasn’t much room on the right side of the battery tray to drill.

Anybody have some pics you could share of how you did this?

Looks like this method was referenced in an earlier post here, but the pics are no longer being hosted:

Appreciate any guidance and/or pointers.



For my hold-down, I bought a length of flat “strap” metal, I guess you’d call it. It’s about 1-1.25" wide, and maybe a 16th thick. Has about a 3/8 hole spaced every 2 inches or so. In the metal rack at Home Depot.

Definitely bendable but still somewhat stiff.

Anyway, on the left side of the battery I drilled a hole in the raised vertical lip of the trunk floor and attached with nut/bolt, and then I ran the strap across the battery, down the right side, and drilled a hole down at the bottom and fastened with nut/bolt. I think given your situation, that may be easier to deal with than the more elegant threaded rod.


my car has two pieces of aluminum bar stock, one vertical piece on the right side that can be installed w/o the batt in place, and a horizontal piece over the batt that attaches to the vertical piece on the right and the chassis on the left. pretty simple design and feels very secure. also remember to glue a thick piece of rubber to the chassis in front of the positive terminal to protect against a short if the batt should happen to slide forward.



Ranger, is that the left (driver’s) side of the battery? That part of it works for me, albeit with nuts and washers instead of the nice welded bit you have there. What’s the other side consist of?


I used two threaded rods and a piece of square stock. It definitely was a tight fit to get the rod inbetween the battery and the body of the car to the right of where Ranger welded his though. Here is a pic before I swapped the too bendable flat stock for some square stock:


I just swapped the oem 90ah bmw battery out of my ix into the spec car for a little generic one and was planning on just running the factory tie-down for now. Despite the old tie down thread I don’t see in the rules where it says I need a supplemental tie-down.


The other side is longer threaded rod that goes thru the sheetmetal below the battery.

@Turbo. Blowing off a rule that is clearly understood by all regional directors as a requirement may not, ah, be the best idea of the week.

I hear what you are saying tho re. it not being in the CCR tho. It’s on my list of rule requests to write up this fall. I don’t have any emotional connection to the rule itself, but since it’s been a requirement for 2-3yrs now, it ought to have found it’s way into the CCR.


I would expect it to be in the se30 rules at least.


I wound up going with a hybrid approach for the time being. Threaded rod on the left side, metal strap on the right. The strap loops down under the battery compartment and screws into the body where I found a convenient spot. At the battery, it’s connected to a piece of square aluminum tube, which is also connected to the threaded rod.

It’s a bit of a kludge, but it works. I’ll take a look at some of the other cars at VIR next weekend and get more ideas. Ultimately I’d like two threaded rods to hold down the square tube, but can’t seem to find room on the right side to attach it. Hopefully I’m just being dense and seeing some examples firsthand will make it click.

Thanks for the ideas!


FWIW the lack of this “supplemental” hold down was one of 2 items that kept me off track an extra day after comp school this spring because the TI wasn’t well pleased. I’m with Ranger here.


Dang, I have never had a “supplemental” battery tie down…I thought that the batteries were designed to be held from the bottom, like stock and that a bar across the top would cause the battery to crack in an accident.By the way, in my 2 big accidents over the years that resulted in totaled out cars, no problem with the battery



Is the factory hold down/set up legal?


I would say, it depends who techs your car.

This year, my factory hold-down did not even raise an eyebrow. however, I got dinged for having a wet cell battery and “openings” in my bulkhead. The openings consist only of the factory openings; the bulkhead is otherwise completely sealed, even where my b-pillar bars pass thru it. Solution? A new dry cell battery, which will require a new hold-down because it can’t be secured at the bottom like a typical battery.

But at least now, I won’t be burned by battery acid in a wreck, ya know. :S


I don’t understand why the TI’s can ding us for “infractions” of unwritten rules. It’s cost me a track day and an extra $150 so far this year. I can hardly wait until next year when I get the next list of undocumented go dos. Is this consistent across the series and across the organization?


Relax–you have a logbook now. Just take it to the guy you used before to get your annual before the season starts.


The series is consistantly made up of humans and is therefore imperfect.

The battery hold down requirement is genuine. The problem is that it failed to turn up in the Jan11 CCR like it should have. It’s on my list of rule change requests to make in the Fall so this will get fixed.

The solid rear firewall requirement is imaginary. A well intentioned TI inspector made the wrong call. Shit happens. Take a deep breath.

Jon Stroup was told his battery had to go into a sealed battery box, so now it is. That inspector was also wrong.


I think a battery box for a wet cell would be a bad idea, concentrate fumes that are explosive… and it is really hard to seal off the rear bulkhead, another reason a fuel cell in the trunk is a bad idea Thin about this, where does your battery cable route? is there anywhere it can get pinched in a wreck? It is a really good way to start a fire. My experience with NASA tech guys has been pretty positive, now with vintage guys not so much.Guys from other teams would give me tech stickers just to keep me away from the tech shed…In my opinion the stock hold down works for batteries designed to be held from the bottom, lessening the chance of cracking due to over tightening or puncture in a wreck



I didn’t take pics of the final product but it involves a motorcycle tie-down and should be good for holding at least 2400lbs of force. The factory tie-down is also in place.




"I don’t mean to be augmentative, sir, but could you show me that requirment in the CCR? Honey, etc…Chuck