Anti-submarine Belt?

[Alphamacaroon]

Curious— for a pleasure driver with maybe an occasional track day here and there, would you recommend installing the anti-submarine belt? Necessity, or overkill in most cases?

For those that say it's a necessity, do you have a recommended way/place to install?

[Papa]

I wouldn't drive one of these cars without it. The Simpson belts really won't work properly if you don't use it and the buckle will end up in your rib cage in an impact.

[Jeff Kleiner]

What Papa said. Despite what some believe it doesn’t keep you from “submarining” by catching you between the legs. It does do by keeping the lap belt properly positioned on your hips...without it the shoulder belts pull the lap belt up. The Roadster seats don’t have pass through provisions but if you mount it as near the front edge of the seat as possible and pull it over the cushion it will serve it’s purpose even though it won’t conform 100% to the mounting recommendations.

Use all 5 all the time...Please.

Jeff

[Jacob McCrea]

I made brackets out of the spacers that FFR provides for using a Mustang pedal box and master cylinder. The bolt is a lug nut with 2 thin jamb nuts (one on each side of the mount, allowing the belt end to wobble) and the end cut off. There is about a 2" x 3" x 1/8" aluminum plate under the floor to spread the load, which is probably overkill. I had to cut a hole in the high-back Kirkeys to get the location of the belt correct (that is to say, per the belt manufacturer's instructions on where it should be relative to your body).

And yes, all the authorities say "all 5, all the time."

Coupe 5th Belt Mount.jpg

[Alphamacaroon]

Glad I checked. I have the kirkey low-backs and they do have a hole for it, so I guess I might as well use it. I guess I just need to find a place to safely mount it. Driver's seat is on tracks and movable, that is going to be interesting in finding a way to adjust it on a regular basis. Thanks all.

[Papa]

I mounted mine through the steel floor plate using just the provided hardware. I have the Breeze seat mounts, so the bracket and bolt don't interfere with the seat mounting.

[Alphamacaroon]

I mounted mine through the steel floor plate using just the provided hardware. I have the Breeze seat mounts, so the bracket and bolt don't interfere with the seat mounting.

Yeah I'm never quite sure if I trust the strength of that plate or not, but I guess for the sub-belt it's probably sufficient. So you mounted it directly to the floor? I'm seeing this might be considered non optimal?

Screen Shot 2020-11-18 at 12.51.59 PM.png

[Papa]

It's not optimal, as Jeff said, but adequate to keep the lap belt positioned across your hips.

[Alphamacaroon]

It's not optimal, as Jeff said, but adequate to keep the lap belt positioned across your hips.

Okay great. Thanks everyone for the excellent info!

[Jim1855]

I have used Cam-Locks in the past rather than the Latch-Link belts. If you attach the Cam-Lock to the anti-sub you'll have to use it. I think the Cam-Locks are much easier to use as well.

As others have mentioned, keeping the lap belt across your hips rather than your gut is real important.

Jim

[Al_C]

My 2 cents: before you drill the hole for the mounting bolt, check where it will be on the underside of the car. Why? Because the brake lines are pretty darn close to where you want to drill that hole. Ask me how I know... (no, I didn't puncture it, but I was pretty darn close!)

[John Dol]

Depending on the seat you may be able to attach it to the seat frame. That is what I did. I figured if my seat gets ripped out of the car in an impact the submarine belt is the least of my problems.

John

[mtwarog]

I did the same as John. Just wrapped it around the seat frame and out the hole in the seat cover. That way it moves when the seat slides with the seat slider.
Right or wrong, I figured the other 4 straps are mounted to frame so this 5th belt will just be holding down the belts in the correct position and didn't need the same frame mount.

Thanks.
-Matt