I bought this car out of Livermore CA in 2018. It's a 6cyl GT Tribute built on a 73 4 cyl chassis with donor parts from a factory six. I know, wouldn't do that today most likely. It wasn't running at the time due to mostly sitting for years. After a refresh of the fuel system and carb rebuild (thanks Jack Morris) it fired right up. New brakes all around courtesy of PMB and new fuel system components from Tangerine Racing. Thanks vendors! A few drives and compression numbers seem excellent. 180-190 on all cylinders. I'm going to pull the motor now to do valve adjustment, belt change, etc.
While the motor is out I'm wondering about how best to prep to install the shoulder harnesses in a better way. You can see from the photos that there is one point through the rear firewall with no extra metal that holds the shoulder harnesses at this point.
I'd prefer not to install a bar behind the seat on the cage due to wanting the seat to be able to go back as far as possible. I'll be mounting a Kirkey or OMP seat I already have. I'm 6-1 and pretty long legged.
I'm thinking about welding plates to the rear firewall about the point you see the 3 plastic plugs currently and then put two eye bolts per side to mount the shoulder harnesses.
The car will be used for some vintage race events and DE's. It was originally built for PCA solo events.
Thoughts, advice, pics of your installs?
Pic of engine compartment with existing eye bolt for harnesses
Current drivers seat
Passenger side with seat removed, same as driver's currently
Gratuitous pics of car
Here's how I did it on my /4. Pay attention to the angle of the shoulder strap through the seat cutouts so best to mount the seat first. You'll also need to add a window net and a fire bottle within your reach. I'll post photos of the install on my /6 in a bit.
Here's the welded in plates on the /6 track car. You will want to mount the seat slam down on the floor in order to get the best angle for the shoulder belts to route--supposed to be no more than 15 degrees below horizontal IIRC. That will mean placing the eye bolts as near to the top as possible--I'm only 5'8" and mine just barely meets.
John,
Thanks. That is very helpful! Would love to see your car some day!
Cheers,
Jerry
Nice seats.
I sold my set just like them years ago
most of the Wheel to Wheel vintage race organizations will require you to have a seat with a submarine strap hole in the seat, and side strap holes in the seat
you may have to modify or replace your seats with safer ones, made for 5 point belts... to be accepted by tech for vintage racing
I should have added....
most sanctioning bodies have their own established rules
those rules usually cover the seat belt mounting angle
the angle changes slightly with a HANS unit
most organizations are now requiring the HANS... not all but most
you may want to seek the rules out for any local groups that you may potentially run with in the future.
our opinions are just opinions.. . the sanctioning body rules will be the standard for your car
I'm the porsche eligibility chair for our local vintage club
I highly recommend you contact the eligibility body for any club you may join... and get advice from them so that you don't have to make updates or changes later.
Brant's advice is good to check with whatever group you plan to run with. Read the rules and talk to one of their inspectors.
One random thing I noticed in your pics - both shoulder straps are mounted to a single eye bolt on the firewall. I think most rules will want to see one per strap. The backing plates shouldn't need to be welded in place, but of course that wouldn't hurt.
I'm fabricating a set of GT style harness mounts, but these will have a full front plate. Back side with have the standard backer plate, spacer and nut that can be welded. Mark
Mlindner's approach could be an interesting one. A couple things to keep in mind:
Check the recommended spacing between shoulder straps. For HANS compatibility, I believe it may be recommended to have the mounts closer together than full shoulder width.
Also, it might be a good idea to make sure the U bolts are at least 7/16" diameter threads. That's standard seat belt bolt diameter. And they should be graded bolts, like grade 5 at least. Common hardware store stuff is often grade 2.
These will have the plates to weld on the back and go around the factory hinges. I'll post more pictures when it comes to mounting. Best, Mark
A bit of an update and check in. Comments and suggestions welcomed.
I have an older FIA certified OMP seat that I picked up with some other 911/912 race parts years ago. Our club won't check the seat certification and it's in good shape. I will need to get a sub belt hole installed which I can do or have a local upholsterer take care of.
I'm 6' 1" so getting leg room was a premium and also getting it as low as possible was a consideration. I may in the end need to have a pro add a small hoop to the cage above my head. I'm well below the bar with no helmet on but may be within an inch or so with a helmet.
After much fitting and cutting off the stock seat mount hinges I think I got a decent fit.
Then to figure out how to get a solid mount. I read through several threads on it and settled on this design which will bolt to the boxed section of the floor with a steel bracket and set of shaped slats I cut and welded. I'll bolt the back of the seat through the floor.
That's the right way to do it...right down on the floor.
Consider the seat you're using and take a look at a newer one that has side supports for the head--definitely recommend dropping the coin to get the added protection. Here's what happened to me in a low speed spin into the tire wall at VIR....
https://www.youtube.com/watch?v=1heYF7JqF4I
Here's the new seat--no impact but you can see the protection that you should have....
https://www.youtube.com/watch?v=R0BU4kyuCY4
Little up-date, picture of the backer plates installed for the GT type harness belts. Mark
Looking good. When you get it done, the roll bar near your head should have the hard SFI padding. I just learned that. I may be doing some belting like this soon. Or I may just do two of the hooks, like you had before.
Yup will do Justinp71....Had a small accident at Road America (canadian corner) some 30 years ago and my helmet hit that roll bar pretty hard. Not again. Mark
OK final product. [attachmentid=787
818]
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