Advice on Mounting my Should Harness for SPF #205

[frankym]

I just learned that my car doesn't have the pre drilled holes in the rear frame rail that would normally receive the bolt for the harness. I also don't have the slit in the rear bulkhead for the single strap. I don't think i have any issue with properly positioning the slit, and using a spiral bit to cut out the space. However, I can't get a drill into the wheel well to put large hole squarely through the square tube up there. I purchased some mounting tabs that look like a flat rectangle about 2.5 inches long, and, I plan to bend the tabs to form a 90 degree angle, mount them flush with the frame upper rail, and use my mig welder to zap a bead. I plan to create a tunnel of aluminum foil in that space so that the heat doesn't torch the fiberglass. I would also weld slowly, to keep the heat down. Am i insane to try doing this?

I know I can purchase the rollbar mounted cross member, but then i have no shoulder harness for the passenger. Thought about it, and i want to mount through the bulkhead with the "Y" single belt, and loop through frame. I wonder if there is a way to get the nylon harness to simply wrap around that square tube and not bolt it at all through the frame rail.

Curious to learn what the earlier spf car owners have done.

[twobjshelbys]

You should mount the driver's harness to the roll bar using a cross mount.

There should not be a passenger harness. You can put one in but it is not advised for two reasons. First the mounting point is below the top of the shoulders, and in the case of a front or rear crash the straps will push the passenger down towards the front of the car. Second, if the car does roll, being veritcal, the passenger becomes the roll bar. Not a good scenario.

Others disagree with this, but I refused to allow my passengers to use the harnesses that were mounted in my car. When asked, Shelby American will NOT install harnesses this way in cars they sell.

Like I said, others will disagree.

[AL427SBF]

If you're not stuck on the ridiculous notion that a replica with modern tech throughout shouldn't have a 2nd roll bar, then problem solved with roll bar #2. You'll probably get a bump in torsional stiffness of the chassis as well.
.

[twobjshelbys]

Originally Posted by AL427SBF

If you're not stuck on the ridiculous notion that a replica with modern tech throughout shouldn't have a 2nd roll bar, then problem solved with roll bar #2. You'll probably get a bump in torsional stiffness of the chassis as well.
.

You are absolutely correct! If you want to drive and enjoy the car with a friend, please add the roll bar. I inquired Shelby about adding it (even sending my car back to them to do it) and they said it would not be cost effective to add due to the finished holes that are present. I didn't ask if they would add it during a build. My point is that even adding one to a SPF might be a costly proposal.

Good luck.

P.S. I will add that the use of the passenger shoulder harnesses attached to the cross member in the trunk is more of a crap shoot concern. If you think you might roll the car, then obviously you shouldn't (and I'll say that a lot of the pictures show cars upside down). If you are worried about the front or rear impact and the passenger is "short" so that the harness attachment point is higher than their shoulders, then it would be "safer".

[DanEC]

Originally Posted by twobjshelbys

There should not be a passenger harness. You can put one in but it is not advised for two reasons. First the mounting point is below the top of the shoulders, and in the case of a front or rear crash the straps will push the passenger down towards the front of the car. Second, if the car does roll, being veritcal, the passenger becomes the roll bar. Not a good scenario.

Others disagree with this, but I refused to allow my passengers to use the harnesses that were mounted in my car. When asked, Shelby American will NOT install harnesses this way in cars they sell.

Had not heard of this theory before - in my case this (no shoulder harness) would apply to me, the driver also. I'm more afraid of imprinting the sunvisor hinges and windshield header across the front of my brain pan and being speared by the steering column than I am of a roll over.

So Shelby doesn't install passenger side, shoulder harneses in cars with a single roll bar? What about no rollbars like the 8000 series cars? Just lap belts?

[twobjshelbys]

Originally Posted by DanEC

Had not heard of this theory before - in my case this (no shoulder harness) would apply to me, the driver also. I'm more afraid of imprinting the sunvisor hinges and windshield header across the front of my brain pan and being speared by the steering column than I am of a roll over.

So Shelby doesn't install passenger side, shoulder harneses in cars with a single roll bar? What about no rollbars like the 8000 series cars? Just lap belts?

No shoulder harnesses in the 8000 series street cars either. At least the pictures of the ones I could find.

[vatdevil]

I had Dennis Olthoff install a race roll bar and 5 point harnesses. Bit of a drive for you, but it's a great shop to visit. My opinion, don't skimp on safety. These cars are dangerous enough.

[strictlypersonl]

The great majority of collisions don't involve rollovers, so there is significant added safety for the passenger being strapped in. Even in rollovers, not being thrown from the car is a big advantage.

[patrickt]

If you love your passenger, then you'll get them a roll bar and four point harness just like yours. If you don't love them, then it really doesn't matter and you won't miss them when they're gone anyway....

[twobjshelbys]

Originally Posted by strictlypersonl

The great majority of collisions don't involve rollovers, so there is significant added safety for the passenger being strapped in. Even in rollovers, not being thrown from the car is a big advantage.

This is true unless the harnesses are above the rider's shoulders. If the are below you run the risk of spinal compression. Neither is good, like I said you have a craps game if you want anything but lap belts.

Make whatever decision makes you feel best but collect all of the data first. There are pros and cons to all of the solutions.l

[twobjshelbys]

Originally Posted by patrickt

If you love your passenger, then you'll get them a roll bar and four point harness just like yours. If you don't love them, then it really doesn't matter and you won't miss them when they're gone anyway....

By the way, that's a pretty strong way to say what I've been trying to say in a rather roundabout way.

Several people, including Bob Bondurant, told me the passenger is usually better off with just a lap belt. Chances are they'll be moved into the center of the vehicle (laying on your lap) and be much better off than the other choices. Then there are chances for other things.

This is the number 2 reason my wife refused to ever ride in it.

[twobjshelbys]

Note also that there is one other way to attach shoulder harnesses. My car was shipped without passenger side harnesses (I asked). When I got it someone had attached the harnesses to the rear bolts that hold the seat rails to the floor!!! Iccchhhh....

[Tom Wells]

frankym,

Here's a quote from the Simpson Racing site:

Anchor shoulder straps at point zero to 10 degrees below the top of the shoulder. Note: Preferred mount is as close
to shoulder as possible.

Notice the straps are not angled upward - doing that is not recommended by any of the belt manufacturers.

Also, if you install the shoulder harnesses remember to install the crotch belts too. They're not a restraint; they keep the lap belt from riding upward in case of a jolt. If the lap belt rises, the passenger can "submarine" and go sliding knees-first into something solid.

So check with your seat belt mfr and note that some recommend up to 4" (or less) below the shoulder line, or up to 40 degrees below horizontal without exceeding 4". Follow their recommendations as to mounting and you'll be good to go.

I can personally attest to the effectiveness of the 5-point system and the dual roll bar system in a 100+ mph rollover and crash.

Can you tell? I think it's a really, really good idea!

Tom

[jhv48]

My wife refused to even ride in the car without both a passenger side roll bar and shoulder harness.

So we compromised.

I installed a second roll bar and shoulder harness.

[twobjshelbys]

Originally Posted by jhv48

My wife refused to even ride in the car without both a passenger side roll bar and shoulder harness.

So we compromised.

I installed a second roll bar and shoulder harness.

My wife's disdain for the Cobra only stopped at the harnesses. That was the so called "straw that broke the camel's back". She got snake bit (every one does, once) even though I warned her just seconds before to be careful of the pipe. She found it uncomfortably hot, etc. Anyway, she made the crossed-fingers vampire cross when she walked by it.

I'll have another one some day.

[frankym]

one of the things i realized is that if i mount the shoulder harness by going through the fiberglass bulkhead, it would be better to mount the anchor as high as possible. If you were to use the superformance pre drilled holes, you would be mounting about 4 inches lower than you could if you utilized all that space up above the frame rail. I am going to try welding my own mount that will dog leg the anchor point to the center of the seat back and about 1 inch from the upper (underside) of the body panel (that area where the rollbar is in). Then you would be less likely to have that downward pull that the shoulder harness would have under the normal place where SPF suggest to anchor, which is pretty low on the shoulders, like mid to upper back.

[twobjshelbys]

Originally Posted by frankym

one of the things i realized is that if i mount the shoulder harness by going through the fiberglass bulkhead, it would be better to mount the anchor as high as possible. If you were to use the superformance pre drilled holes, you would be mounting about 4 inches lower than you could if you utilized all that space up above the frame rail. I am going to try welding my own mount that will dog leg the anchor point to the center of the seat back and about 1 inch from the upper (underside) of the body panel (that area where the rollbar is in). Then you would be less likely to have that downward pull that the shoulder harness would have under the normal place where SPF suggest to anchor, which is pretty low on the shoulders, like mid to upper back.

Can you post a sketch of your design? If you are doing what I think it won't be structural but I need to see a drawing.

If you have:


+--------------------------ooooo---------+

where + is the anchor point of the cross member to the frame and o is the SPF cut out, and you are proposing doing:



+--ooooo--+
| | <your new work welded to
| | <existing cross
+-------------------------ooooo---------+

The weld will break and even weaken the existing cross. But maybe I'm not understanding what you are proposing.

It might be better if you come through at the upper position, add your welded material but still attach the belt to the lower cross member. Then the forward motion will still probably take out your added work due to the forward motion, but it will absorb some of the energy and at least the belt will still be attached to a structural entity.

[frankym]

Tony, i'm going to try to weld up the piece tonight for the driver side (if i get home early enough), I may not weld it into place quite yet, but i'll take some photos of the piece in position and post it here, otherwise, we'll be building a tower of babel, with texting about sketches and drawings and imagining positioning.i have 1/8 inch dimensional DOM tubing and 1.25 inch angle steel to work with , also have a bug welded up for the thread. all will make sense when you see the unit.

[DanEC]

ERAs mount to a steel chassis member just under the rear cowl - about as high up as possible other than mounting to a roll bar.

[frankym]

Last night i made the draft part. I need to cut into the bulkhead for final positioning on the car.