2 point or 3 point?

Since I have the car stripped down to metal inside and out, I’m figuring that this would be the proper time to start planning the seat belt set up. Any body here install seat belts yet? Did you use the old 2 point belts or did you instal the 3 point with shoulder strap?
I’m finding that the two point system is cruising the door. I’d hate to stress the new leather by having it squished between door and seat.
Any suggestions??

I bought 2 point belts for my Mark V but have not yet installed them.
I have 2 point belts in my XK120.

Damn boy, you have some nice iron!

I installed seat belts in my 1950 Mark V saloon. They are two point belts. If you would like photos of any of the various mounting details or how they lay in the car when unused, just say the word.

Do take an engineering point of view on installing such belts, they will do little in terms of safety. They give an impression of safety which comforts some passengers. I still drive with the fear of God in place since other modern cars and drivers are on the roads as well. Basically, I found mounting positions in the flooring which have proved good placement over the years. These positions were strengthened slightly by use of large washers under the floor at the mounting points. I imagine an accident would still impale me on the steering wheel and send a front passenger’s head through the windshield. Those imaginations are separate from the concern that the washers would just pull directly through the floorboards on severe impact.

Still, I’m glad to have installed the seat belts.

My imaginations about steering wheel and windshield impact include the stretching of the belts during impact. A static concept is not correct for seat belt action during an accident.

While racing in Spec Racer in SCCA, one time my race involved a rather abrupt termination of playtime. I still remember the amount of stretch a 5-point belt system did in the moment. That stretch is very important to keep the g-load down while enduring an impact. I also remember being very glad I always wore a horse collar to reduce chin planting in the chest. And the seat belts were replaced before the next use of the car.

I was thinking that I could attach a third point in the door pilar figuring it might keep the windshield in better shape if I decide to test braking power without the brakes.

If the attachment point allows the belt to be at a proper angle, it’ll be better than nothing.

Another SR racer!

I drove a Sport Renault (chassis #3) in my first two seasons of SCCA road racing.

Never got to to test the belts, though…!

Hi Wayne,

I have installed three point safety belts in the front of the MKIV and two point in the rear.

I had reinforcing pieces welded to the chassis frame for the lower mounts and substantial piece welded into the central pillar. There are special, very finely threaded nuts into which the belt bolts are screwed which are welded to the mounts. They are very substantial mounting points, especially those mounted to the chassis. I’d be interested in your thoughts Rob and Peter, and any others with engineering backgrounds.



I don’t know if they would be as effective as any modern setup but even if it retards the forward momentum in the awful event of a collision and lessens any injuries, it will have been worth it. That being said, when I drive the car I am so, so careful and tend to drive very defensively. I don’t have safety belts fitted to the MKV and I do feel vulnerable.

When I was in my early 20’s I had a head on accident while driving my beautiful MKII. It had factory fitted belts and they saved my life. The other driver just veered onto my side of the road on a straight stretch of road on a clear day with no warning. He was driving a small Nissan Pulsar and was seriously injured. I just opened the door an hopped out of the car. The Jag was a right-off, sadly.


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Thanks for the photos. I had welded 4” x 4” plates under the floor on my V but once I bolted the seat belts to them, the retractor was squished against both the seat and door. I am now thinking of using three points and moving the retractor back to the base of the pilar. I’m trying to figure the best place to weld in a plate on the door pilar. Now I can use your positioning as a guide.

A good friend in the Register fitted inertia belts to his MKV which I think allowed him to mount the inertia reel through the floor onto the chassis rail. I’d have to ask him and get back to you.

I’m keen to hear what the engineers on the Forum have to say about the MKIV set up.



The belts very definitely stretch. A lot. But the human body will stretch much more. What you can touch strapped in tight bears little relation to what your extremities will come into contact with in a big hit.

At 9:15 PM on the 9th of May, 1984, my brand new Honda CRX was hit head-on in the left lane of I-64 by a drunk driver in a 1974 Ford Torino who was eastbound in the westbound lanes. No doubt the belts saved me from very serious consequences. All my injuries were the result of the belts. I suffered torn cartilage between my sternum and rib cage and burns to the top of my left shoulder and both hip bones. Friction from the shoulder belt melted a diagonal stripe across the front the Nike warmup jacket I was wearing.

I’m no engineer, but I can work out the approximate maths, on that one.


December 18, 1991, a Chevy Caprice, estimated to have been traveling at ~58 mph, broadsided me, in the driver’s door, of my '80 Datsun B210.

I’ll let you do the physics.

The reason the speed of the Caprice is well-known is… it was a police cruiser. The belts saved my life.

Once they located the Datsun…

They did not save me three months in the hospital.

(4,000lbs x 58mph^2) x B210 = Hospital.

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We’ll call it The Paulie Equation


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Tim, I’m not an engineer, and to do a full assessment of your install would be… challenging, but if you got the belt placement correct, on your person, they will work fine.

Forgot to divide by 2! (4,000 * 58^2)/2

Either way = Hospital.

Remind me sometime to tell you The Yogurt Story:grimacing: