I have a mk 2.5 sport and have fitted a T R Lane RB with welded in harness bar so top fixings for my 4 point harness will be wrap round. Sorted.
I will be using some cloth seats as they have slide in head restraints and I’ve performed a “foamectomy” on the drivers one so I fit when wearing a helmet.
The one remaining thing is to drill/weld the bottom two (4 if I do the passenger side) harness fixings.
Any advice on position etc ? Angle the belt should be ? A photo through the open door would be good.
Any help would be appreciated,
Paul G
p…s. I would like the existing seat belts with their clasp on the side of the seat to remain for road use.
There is a load of info on a Google search, videos etc. Maybe not model specific for your car but general principles apply. On my mk1, I utilised the OEM lower fixing points for the anchorages, at the same time retaining the OEM belts. New eye bolts were purchased, they are standard 7/16th UNF and clip in fixings for the lower harness. Fortunately, on the early mk1’s, the inner seatbelt fixings are a captive nut on the transmission tunnel, so easy to do. Not sure your inner ones are like that? Probably on the seat frame? A spreader plate will be needed, welded to the underside of the transmission tunnel, hole drilled through tunnel to align with captive nut on spreader plate and away you go. Position wise, directly opposite the OEM outer fixing point, or as near as will allow. People like demon tweeks sell the range of fixings/ plates etc
Check that transmission tunnel. There may be an unused hole with a plastic plug. This is the location of the tapped hole used on early MX5 seatbelt latches. The same part, with a light modification was carried over into the NBs. There’s no captive nut anymore (I think) though.
The blanking plug is visible on this stripped 2004:
If you mean the bottom right in your photo then that is passenger side only and on my car it has a grommet and the wire to the rear lambda going through it.
I managed to drill a hole and weld the nut & plate on. Job done.