There are several options available in most racing harnesses. The primary option is bolt-in v.s. snap-in. Snap-in harnesses clip into eye bolts installed in the car and can be removed leaving only the eye bolts. The eye bolts have the same thread as standard seat belt bolts, so it is usually possible to replace the stock seat belt bolt with an eye bolt and all is well. Many new cars, though, have one end of the factory belts attached to the seat with a different mechanism than "standard" bolts, and sometimes there are clearance problems with eye bolts. These may require drilling a hole in the floor pan and mounting the bolt there (always being careful to use a sturdy backing plate behind the bolt to keep it from pulling through the sheet metal in an accident!). In the MkII MR2, the outside seat belt bolt could be replaced with an eye bolt, but that's about it. Therefore, I went to a bolt-in harness. When not in use, the lap belt and the sub straps get pushed under the seat and are not noticeable.
Another option is pull-up v.s. pull-down. This has to do with which way you pull the strap to tighten it. I went with a pull-up harness and it seems to work well, but I don't see any reason that a pull-down wouldn't work. Finally, the shoulder straps can be either two separate straps, or they could join in a Y behind the seat. The Y straps are not approved for SCCA road racing, but you'd need a roll cage for that anyway. I used two straps, but I have seen the Y straps used as well. Finally, anti-sub straps are an issue. In SCCA Solo II stock class, it is not allowed to cut the seat to install the sub straps "properly", so I have installed them as best as the rules allow. I have a six point harness, with dual sub straps. This works well as they attach to the front of each seat rail. A five point harness would have to attach to the floor pan, only one of the seat rails, or to a custom bracket strung between both seat rails. The sub strap has marginal functionality without cutting the seat, so you might consider just leaving it off entirely.
I got my harness (TRW) from Racer Wholesale, in Roswell, GA. Their phone # is 800/886-RACE(7223). The harness was a little under $100. There was nothing special about the harness except for a decent price. I believe that these instructions will work for practically any harness.
On the outside side of the belt, I just added the harness end onto the seat belt bolt. This allows the OEM belt to function normally or the harness lap belt to be used. On the inside, the OEM belt buckle attaches directly to the seat. There is a retaining strap, however, that extends behind the seat to a metric bolt on the side of the tunnel. I attached the inside half of the lap belt to this bolt. It is approximately the same size as the standard seat belt bolts, so the harness bolts in solidly here. See the diagram.
The sub straps are attached to the front of the seat adjustment rails. The seat is bolted to the floor of the car at the front and rear of two rails that allow the seat to slide forward and backwards. I had to loosen the rear bolts to allow enough clearance in the front to get the harness ends under the rails, but everything fits OK. On the driver's side, the fuel door/rear trunk release has to be temporarily removed to get at the seat rail. Also, I did have a clearance problem with the harness end and one of the two screws that hold the fuel/trunk releases in place. I went without it (the 2nd screw) for most a year until I got an end plate for the harness with a longer neck (sorry, I don't remember where I got it from, though). It is difficult to adjust the lengths of the sub straps since the end plates are tight against the floor, so it is probably best to not tighten the front bolts much before adjusting the fit.
Finally, the shoulder straps are bolted in using the hole behind the seat where the coat hook is. Pry off the bottom half of the hook to get at a screw that holds the hook in place. This is actually reinforced pretty well since it is the same place where the child seat bolts in on the passenger side (The functions are reversed for a right hand drive version). You will need an 8mm bolt for this hole. Be sure to use a high grade bolt (Grade 8.8). I don't remember the length needed, but it is commonly available. Also, you will need a couple of washers to make sure that the harness ends don't pull off of the bolt. I also added a couple of spring washers and two nuts locked together so that the bolt can turn freely inside the harness ends to bolt into the car for easy removal during winter. I normally leave the shoulder straps in during racing season.
Marcus Hall '94 MR2T - Solar Yellow!
Date: Tue, 18 Feb 1997 23:03:23 -0500 From: Simon Tremblay (tremblsi@ift.ulaval.ca) I write you about certain modifications articles that I found on the site. (...) There is also something that is always on my mind and it is about the safety of those that installed safety harnesses using the attatch point behind the driver seat similar to the baby seat attach point. It is extremely dangerous to do so and someone using this attach point put it's life in stake! This point is NOT strong enough to sustain the force of a crash. The information article by Marcus Hall is wrong in that way of thinking. The article should be corrected. I found out about this when I cut that part away to install my racing harness properly. It is only thin sheet metal and will tear if a crash occurs. I cut it away to install a thick steel bar behind the firewall to attach my harness. Simon Tremblay tremblsi@ift.ulaval.ca
Date: Fri, 16 Jul 1999 02:09:19 -0700 From: Thomas Harrington (tomh@lvcm.com) Subject: MR2 Harness Install http://www.mr2.com/OWNERS/harness.html I was reading the above article about installing a harness in your 91+ MR2. I noticed the comment at the bottom about the harness failing and taking your life into your hands. Perhaps a suggestion should be added. During normal use of your racing harness, once your secured by the harness, put the stock seat belt on over the harness. That way is the harness fails, the stock belt catches you. Thanks for maintaining a great site. -Tom 95 MR2 Turbo w/ TRW Sabelt 4 points.
