Harness Install - NB

yods · Postby **yods** » Mon Apr 21, 2014 7:51 pm

I've got a few questions about installing a 4 point harness on my NB, as (with most things) its slightly different compared to the NA models. Car is an 01 NBB, with a Sparco sprint V on standard rails and an MX5 plus roll bar. The intent is to have all 4 eyelet bolts installed with the harness left our except for track days.

1. Seat belt locates to seat rather than to transmission tunnel. Posts from the states indicate there's a hole to be drilled which probably requires a backing plate. Is this this the same for our (RHD) cars or might there be a magical threaded bolt there somewhere.

2. For the drivers side, the instructions indicate to use the lower seatbelt mounting point (makes sense). However the number of washers and spacers make this impossible with the supplied eye bolt - where can I source good, high tensile strength eyelet bolts? (I am assuming the spacers are required..)

3. Anyone got any install pics from an NB they can share?

Cheers
Peter

de Bounce · Postby **de Bounce** » Mon Apr 21, 2014 8:11 pm

You will need to drill the hole for the inside (tunnel) mount.
Thread series for the seatbelt mount is a little unusual, might need to go to somewhere like Revolution Racegear to see if they have longer eyebolts.

timk · Postby **timk** » Mon Apr 21, 2014 8:13 pm

Yes you have to drill and fit your own backing plate.

MX-5 Plus sell a kit to convert the standard bolt to an eyelet - it contains an extended eyelet bolt and some machined bits so the seltbelt can still freely pivot but not rattle.

Cheers

yods · Postby **yods** » Tue Apr 22, 2014 8:19 am

Thanks for the quick replies all. I'll check those out. Is there anything in the way of putting the backing plate in when I get under the car? Or should be plenty of clearance?

zorak · Postby **zorak** » Wed Apr 23, 2014 7:33 pm

Not really - just make sure you drill clear of the seam so that the plate sits flush and not on the seam

Trackphotos · Postby **Trackphotos** » Wed Apr 23, 2014 8:04 pm

Any reason you are going with a 4 point and not 5 or 6? I know a couple of people who have suffered fractured/broken ribs from crashing without anti-sub straps, and I can't think of a good reason not to go for the 5 or 6 point instead.

timk · Postby **timk** » Wed Apr 23, 2014 10:52 pm

Just be careful when doing the 5/6 mounting point as the fuel lines run along there. Also use plenty of Sikaflex around it so water doesn't get in.

yods · Postby **yods** » Fri Apr 25, 2014 12:29 pm

Thanks guys. For anyone searching for this, $15 for both a longer eyelet bolt and a backing plate. It's just a 4 point harness so shouldn't need to go near fuel lines at all, but I'll be doing carpet out as well.

greenMachine · Postby **greenMachine** » Fri Apr 25, 2014 1:42 pm

I suggest you educate yourself a bit about seatbelts, submarining and neck injury (as in, death from).

There are threads on here, do a search.

:mrgreen: