zullo

Quick question re harnesses

I'm ordering a 5 pt harness and deciding between pull-up and pull-down. My only experience is with pull-down, but not in an RX-7, and I had no complaints.

Does anybody have an opinion or preference? Will pull-down be a problem in our cramped cockpit?

For whatever reason, the harness I'm considering has an FIA tag for the pull-down but not for the pull-up. Any ideas why? I don't need the tag for any events I drive, but am curious if it reflects a superior harness.

macdaddy

1. Pull-up vs. pull-down lap belts won't really matter if you're using stock seats. It's more of an issue when you're using a racing seat, where the lap belts go through holes in the high sides of the seat. In that case, it sort of depends on the belt, the seat, and how much room you have as to which is easier to pull tight by yourself. If you have a crew helping you, you'll want pull-up belts so the crew can pull on them.

2. As far as FIA-rated belts vs. SFI-rated belts, they specs are somewhat different, but whether it matters to you depends on whether you have to meet a particular organization's tech regs. You'll generally pay more for FIA-rated belts. SCCA recently changed their club racing regs so that SFI-rated belts have to be replaced every 2 years. They will currently allow FIA-rated belts for 5 years. For open-track/HPDE use, I wouldn't have any problem using SFI belts for 5 years - I clip mine in and out, so they get less UV damage than the stock belts, which are now 11 years old, but which will meet tech.

macdaddy

Another point. For a 5-pt harness to work correctly, you should have a hole in the seat for the submarine strap - just running it forward over the edge of the stock seat, then down to the floor is frequently done, but is not a good idea - in a "sudden deceleration", in that configuration, there could be enough slack in the sub strap from compression of the foam at the front of the seat that it could allow the lap belt to rise up onto your abdomen, rather than staying across your pelvis. This can lead to severe abdominal injury, up to and including death. So if you have stock seats and are going to use 5-pt belts (through-bolting the sub strap to the floor with a BIG backing plate), then cut a slit in your seat and run the sub strap through it. You can get an upholstery shop to pretty it up for you, if you like. If you have a race seat, it will of course have a hole for the sub strap .

Another option is to use 6-point belts. The 2 sub straps can be mounted to the same point as the lap belts. You sit on the sub straps, pull them up between your legs, and fasten the lap belt, etc. This keeps you from having to cut a hole in the seat, and you don't have to drill a hole through the floor, either. You'll see this with a lot of the newer high dollar cars (M3s, 911s, etc.) on track. My understanding is that SCCA is planning to change their minimum requirements to 6 point harnesses from the current 5 point, so they, at least, feel the 6 point belts are safer than 5 point belts.

zullo

Fantastic! Excellent info! That is exactly the kind of insight I was looking for.

Follow-up question: If I go with 6-pt for the stock seat, would that harness be compatible with a racing seat? Or are the 6-pts specifically for stock seats that don't have the hole for the sub strap?

Thanks for taking the time to type the thorough reply!

macdaddy

The 6-points were originally designed for formula cars where you are in a semi-reclining position. If you have a typical race seat with two holes for the shoulder belts, 2 holes for the lap belts, and 1 hole for the sub strap, you can use a 6-point belt, but you would want to anchor the 2 sub straps directly through the floor so that they came up through the substrap hole in the seat. My race seat (and most race seats I've seen) have enough vertical distance between the seating surface and the lowest part of the lap belt hole that I don't think that mounting the sub-straps to the OEM seat belt bolt locations and running the straps through the side holes and sitting on them would work very well - they would have to run up over the edge of the hole, then back down under your upper thigh, then back up in your crotch to the buckle. Tightening the substrap would pull up on your thigh and would be uncomfortable. Now if the bottom of your race seat's lap belt holes are right at the level of the seating surface, it would work OK.