NA harness mounting with a BD roll bar

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deags
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NA harness mounting with a BD roll bar

Postby deags » Thu Apr 13, 2017 9:16 pm

Hi,

I am just wanting to clarify I am mounting eye bolts correctly on my BD roll bar on my NA6.

Here is a photo from someone else's NA with the same set bar as me, and as far as I can tell the mount points are the same -
https://i.imgur.com/g5OfSrT.jpg

The far one in this photo, looking at my car, is the same bolt hole that's used to bolt the bar to the car? So it's doubling up as a bar mounting bolt and for a harness?

My concern is that these eye bolt points do not line up very symmetrically with my seat. I won't know if this is an actual issue until I get my harness fitted though.

The bolts currently installed are 10mm - eye bolts are usually 7/16" and the existing welded-on-nut is for a 7/16". I am going to need spacers to attach the eye bolt to this nut because the thread is too long and wants to go through the parcel shelf... so my bar seems a bit strange?

Thanks

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Re: NA harness mounting with a BD roll bar

Postby manga_blue » Thu Apr 13, 2017 10:03 pm

I never used the eye bolts at all, just looped the belts directly around the lower, flat bar of the BD. That meant the belts pretty much positioned themselves correctly and there was no worry about the eye bolts smashing the glass window (if you have one).
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deags
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Re: NA harness mounting with a BD roll bar

Postby deags » Thu Apr 13, 2017 10:27 pm

I have the carpet under my bar so there is no clearance. to get the belt under that bit. My harness has 3" shoulder straps - I don't think the right side strap could wrap around anything because the bar doesn't extend that far?

I have a hard top and plastic soft top so no issues with eyes smashing anything :)

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Re: NA harness mounting with a BD roll bar

Postby greenMachine » Thu Apr 13, 2017 10:35 pm

Eyebolts have not troubled my glass window, but if that is a worry it is easily fixed.

With HNRS becoming de rigueur these days, getting the angle right is important. When I first installed mine I drilled an extra hole to better line up the belts, and now this works well with my HANS.

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RS2000
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Re: NA harness mounting with a BD roll bar

Postby RS2000 » Fri Apr 14, 2017 8:29 am

deags wrote:The far one in this photo, looking at my car, is the same bolt hole that's used to bolt the bar to the car? So it's doubling up as a bar mounting bolt and for a harness?


That's are definite no-no according to CAMS regs. See Schedule I Safety Harnesses (Sect 2.1) in Cams manual

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Re: NA harness mounting with a BD roll bar

Postby ianoz » Fri Apr 14, 2017 12:08 pm

I have an NA6 with Brown Davis bar for plastic window - the brace bar goes back diagonally towards the passenger rear - and saw the same CAMS issue with using a mounting bolt hole for a harness bolt. That's what the instructions said to do, and given BD have been around so long they should know what they're doing, but I played safe and drilled a separate hole as well. That also put the harness eye bolt in a better position.

Don't know if the BD bar for glass window is the same (brace bar goes straight across instead of to the rear), but photo's i've seen seem to show the harness bolts in a better spot than the plastic window version.
NA6 '89 red, NB8B '01 silver

deags
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Re: NA harness mounting with a BD roll bar

Postby deags » Sun Apr 16, 2017 8:40 pm

ianoz wrote:I have an NA6 with Brown Davis bar for plastic window - the brace bar goes back diagonally towards the passenger rear - and saw the same CAMS issue with using a mounting bolt hole for a harness bolt. That's what the instructions said to do, and given BD have been around so long they should know what they're doing, but I played safe and drilled a separate hole as well. That also put the harness eye bolt in a better position.

Don't know if the BD bar for glass window is the same (brace bar goes straight across instead of to the rear), but photo's i've seen seem to show the harness bolts in a better spot than the plastic window version.


Thanks ianoz, would you be able to post up a copy of that manual? I've not been able to find it anywhere.

The bars BD currently sell appear to have 2 harness points and 2 mount holes on either end of the flat bar, very different to mine. But, the stock photo for the glass/plastic top versions are the same so those photos might be misleading:
http://rollcage.com.au/products/rollcages/

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Re: NA harness mounting with a BD roll bar

Postby RS2000 » Mon Apr 17, 2017 1:13 pm

Go to www.cams.au then
Motorsport/regulations/cams manual/general requirements for cars & drivers/ schedule I

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Re: NA harness mounting with a BD roll bar

Postby 93_Clubman » Mon Apr 17, 2017 5:17 pm

deags wrote:would you be able to post up a copy of that manual?

Assuming you're after the BD install manual - here's a couple of guides:
http://www.fastdump.net/594041-Brown%20 ... 20tips.pdf
&
https://app.box.com/shared/pmozzlc47l

deags
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Re: NA harness mounting with a BD roll bar

Postby deags » Mon Apr 17, 2017 10:29 pm

Thanks RS, I am familiar with the CAMS manual and can see you are right that they expressly do not permit sharing mount points.

I have seen those BD install guides but am under the impression ianoz has one published by BD - or is that one from BD?

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Re: NA harness mounting with a BD roll bar

Postby 93_Clubman » Tue Apr 18, 2017 10:50 am

Believe the first one was put together by an MX5 Club of SA member, while second one was put together by Bigdog. Had a look to see if I had another version archived, but nothing else found. Hopefully ianoz can help.

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Re: NA harness mounting with a BD roll bar

Postby ianoz » Wed Apr 19, 2017 10:36 am

Hi deags
sorry - hunted high and low in the shed but blown if I can find anything :evil: It's been a few years and possibly I was thinking the guides mentioned..??.. but I was sure it talked about the harness mount points. I blame old age :oops:
NA6 '89 red, NB8B '01 silver

deags
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Re: NA harness mounting with a BD roll bar

Postby deags » Wed Apr 19, 2017 3:40 pm

No worries mate, appreciate the effort!

I fitted the eye bolts today as per those guides - going against CAMS but I am not racing (just track days) and no one else has gotten grief for this before that I know of so should be ok :)

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Re: NA harness mounting with a BD roll bar

Postby DarrylA » Thu Apr 20, 2017 1:52 pm

If using the eyebolts, DON'T put your hood down.
Brocken glass widow is a surety.

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Re: NA harness mounting with a BD roll bar

Postby greenMachine » Thu Apr 20, 2017 4:15 pm

DarrylA wrote:If using the eyebolts, DON'T put your hood down.
Broken glass widow is a surety.


Sorry, I call BS on that. I have tracked my car for over 10 years with those eyebolts, and never had a problem. I don't use any additional protection for the glass, and just drop the top as and how it folds. I have not heard of anyone having a broken window for this reason, but I guess it is possible, especially if you are in the habit of carrying (dropping?!) heavy stuff there. Whatever, 'surety' it is not.

If the OP is worried about that, fold a towel and put it over the eyes, or a piece of carpet, or something.

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