Mounting harness sub belt

87turbolook911 · 87turbolook911's Garage

Hi all,

Getting ready to install 5 point harnesses in my car for the upcoming DE. I have a roll bar where the top two belts will attach to. For the waist belts, I have an eyebolt in stock seatbelt locations by the door. I plan to get a bracket that attaches at the seatbelt buckle mounting point.

The question is how do I mount the sub belt? I really do not want to drill a hole in the floor of the car. Are there good alternatives?

Pics would be appreciated.

Quicksilver · 05-17-2005, 12:04 PM

Well you can drill or drill. Which do you want to do?

It really needs a sub strap. You could rig up a bar that bolts to both seat mounting points on each side but I think it would be VERY unsafe in a real accident. The loads we are talking about are very high and the bar would be in a bending load which is bad.

I would recommend that you bite the bullet and drill the hole and back it with a plate that is at least 9 sqr inches. If you have a DME you can easily mount it rotated forward 90° to the left with the stock wiring.

edward993 · 05-17-2005, 12:18 PM

For safety reasons, the sub strap needs to be as short as possible. So if you choose to do anything other than drill a hole and mount underneath the slot, you will be compromising your safety if you ever have to "use" that harness. Besides, the hole is easy to drill and seal off to moisture, if that's you're concern (I doubt you're worried about Concourse since you are putting in a harness).

Edward

87turbolook911 · 87turbolook911's Garage

So where should the hole be drilled? directly under the seat hole or under the persons butt?

ozz · ozz's Garage

Schroth recommends no more than 20 degrees fore or aft of the point where the anti-sub belt drops thru your seat. Some people suggest mounting this directly under your tailbone or just behind your tail bone but, I chose to follow the manufacturers recommendation and mounted mine roughly 2" rearward of the center point (just less than 20 degress) and it seems fine. And Edward is right on point, buy or make a backing plate and before you install it, put a ring of RTV on the plate around the hole and tighten it down. This will compress the RTV and seal it nicely.

Noel · 05-18-2005, 04:40 AM

Check out this thread on Rennlist. Lots of good mounting info. There are many other threads on the Rennlist racing/DE forum discussing this topic.

Rennlist Thread

JackT · 05-18-2005, 05:03 AM

Another alternative is to get the 6 point sub belt and bolt it to the same place you bolt the lap belt. If you are going to use the stock seat you will sit on the straps and pull up between your legs. The 6 point stap is about $20.00.

87turbolook911 · 87turbolook911's Garage

Looks like I'll be taking the drill to the car

Just ordered Brey Krause mounts for the sub belt and tunnel side mount.

It'll be this weekends project.

Thanks for all of your input!

tomt · 05-18-2005, 10:50 AM

I have a bracket that Speedware made which mounts between the seat and the seat rails. The bracket uses all 4 seat mount points, and is a solid steel plate. The sub belt is mounted to the front cross bar of the bracket..

The bracket also has a mounting point for the inboard stock seat belt and the lap belt for my 5 points and Recaro SRDs... Works pretty slick.