Harnesses

Non-engine, eg: aerodynamics, gearboxes, brakes, suspension
Guy Croft
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Re: Harnesses

Post by Guy Croft »

UNF seat belt fixing thread on a Japanese car, are you sure?

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cantfindausername
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Re: Harnesses

Post by cantfindausername »

According to someone on the American MR2 forum. Apparently this is a generic thread used across all manufacturers, both foreign and domestic.
Lap belts
These are relatively easy to install. All cars whether foreign or domestic, use 7/16" thread for the stock seat belt mounts in the chassis. If these are available you can usually mount the lap belts to these points. They will typically have the correct angle and in the MR2 they mount up perfectly!
TR-Spider
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Re: Harnesses

Post by TR-Spider »

I've just been looking further into the mounting of the harnesses, and 1 problem with the MR2 is that the inner mounting point (where the stock seatbelt clip is located) is actually a male thread. So I need an eye nut on this part.
Why dont you use a non-clip end (not a hook) to connect the harness on the inner side and bolt on directly?
Some manufacturers (as schroth.com ) offer lashes with 2 holes, to bolt one side and clip the hook into the other.


Thomas
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Guy Croft
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Re: Harnesses

Post by Guy Croft »

Photos - please Ant at this time!

Remember there will be some readers who have never actually seen a race harness.


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cantfindausername
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Re: Harnesses

Post by cantfindausername »

I'm working on getting pictures from a friend who is struggling with the same problem. I'd do it from mine but its 200 miles away and I've only seen it once in over 18 months.

Thomas, I will have a closer look at the schroth belts website. Thanks.
SteveNZ

Re: Harnesses

Post by SteveNZ »

cantfindausername wrote:According to someone on the American MR2 forum. Apparently this is a generic thread used across all manufacturers, both foreign and domestic.
Yes it is true, all manufacturers use the same thread for the seatbelt anchorages.
cantfindausername
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Re: Harnesses

Post by cantfindausername »

Thanks for clarifying Steve.

I'm still waiting for a friend to confirm the thread size on the inner mounting point for the lap restraints. I've asked (must be) a dozen people so far and no one has confirmed the size. So frustrating!

Hopefully a friend of mine will be getting me the information later this week though so I can then finish off the planning for the mounts.
SteveNZ

Re: Harnesses

Post by SteveNZ »

Having a male stud on the body for the mount is very unusual. Motorsport regulations in New Zealand at least, require a much larger plate than what any manufacturer seems to use. You maybe better of just making another mount and using a bolt like usual.
cantfindausername
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Re: Harnesses

Post by cantfindausername »

That is a possibility. I may do that with the inner and outer lap anchorage points so I can position them exactely as I require, rather than in the stock location. Again, without the car its hard to know. One posibility I'm toying with is getting an eye bolt, cutting off the thread and then drill/tap it to the 7/16" UNF thread (if that is the size of the stud) - thus making it an eye nut. All thoughts running through my head at the mo.

Ant
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Re: Harnesses

Post by Daveyboy »

Get a current MSA Blue rule book, it will show the exact requirements for seatbelt locations and specifications, in previous books it always showed alternative methods of securing belts if eyelets etc. were unsuitable. I recall drawings of steel plates with the belt wound round it and bolted together. At the very least you will be sure the car complies with the relevant regs as well as bieng safe.
GC Book # 103
Guy Croft
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Re: Harnesses

Post by Guy Croft »

cantfindusername sold his car a while back, no point continuing his particular thread, but thanks anyway Jim,

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DeltaDave
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Re: Harnesses

Post by DeltaDave »

Guy Croft wrote:Proper placement of the mouting points is critical, esp the over shoulder-straps. Phil will know all this BTW if he is installing them..

GC
As Guy says the fitting of the over the shoulder straps is critical. They should be fitted in such a position that they are between horizontal and 10 degrees below horizontal. Any sharper angle will compact your spine in the event of an accident and any shallower will not hold you down in your seat. The best reference for safely fitting harnesses is the MSA Blue book there is a section on the subject.

I have many times seen "boy racers" use the rear lower seat belt anchor points for the shoulder straps because the eyes just fit so perfectly causing a massive downward angle of 45 degrees or more (easy, lazy solution, and possibly life changing or deadly) DO NOT DO IT.
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