Miata Mailing List: July 1998, Message #116

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>From: randall.flowers@mailbox.swipnet.se (Randy Flowers)
>Subject: RE: race belts (harness attached to floor bolts)
>Date: Wed, 1 Jul 1998 10:28:55 +0000
>
>>Otto wrote:
>>
>><was advisable to use it to hold a racing harness.  Any one have   
comments and
>>advice?  Are there any other places to install the harness?
>>
>>If it's not healthy to use the tower brace, can I do what I've seen   
people
>>do which is drill holes and stick huge washers and bolts in their OTM?   
 Is
>>there a good place to do this in the Miata?>>
>>
>>Loop the harness over the brace and down to the floor.  Use the seat   
bolts on
>>the floor to hold the end of the harness.  Attach the lap belts to the   
current
>>seatbelt bolts.  No hole drilling required.
>>
>>Bill and Cujo
>
>WILL this actually work and be safe?...if so, what seat belt harness   
should
>i buy
>and from whom?
>I would REALLY like to add a harness to the drivers side, since i will   
be taking
>off the airbag and adding a MOMO wheel and would like my safety factor   
back...
>
>randy
>:)

I was about to respond to Bill, but then I saw your question, and it all   
ties in...

In New Zealand, this is not race legal. Seat belts are not allowed to be   
deflected more than 30 degrees around a bar... Any more than this and   
forces in an impact will be working not only the belt anchor point, but   
also on bending the bar, and ripping the bar off its mounts....

On the "big washer" idea, there are minimum specified washer sizes,   
thicknesses, there has to be a washer on both sides of the panel being   
bolted to, and they have to be different sizes.... rules rules rules. You   
may not be racing, but I find race rules to be sensible guidelines when   
modifying saftey related items...

Race rules may differ from country to country, but the rules of physics   
usually dont... ;-)  (actually our safety rules are based on FIA   
recommendations, and I'd guess most other places are as well, so there's   
probably not that much variation)

Also, as has been mentioned on this list before, Unless you have a roll   
bar, having both shoulders pinned to the seat-back is of questionable   
value in the event of a roll-over....

If this is for a road car, you will also need to check out your local   
laws, here, to use anything but the manufacturers supplied belt requires   
engineering certificates and other government departmental approval   
rarely given to anything but race cars....

Fletch.  

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