I'm not sure of the low windshield cars, but the '68 and newer has (2)
threaded roll bar mounts built into the trunk panel and (2) at the
parcel shelf behind both seats - perhaps you can mount a tab to these
existing locations. Everything I've heard indicates that the mount
should be slightly lower than shoulder height - walk through the pits in
any racetrack and see what the racer's are doing. Mounting to the floor
behind the seats with the belts almost parallel to the seat back will
compress the spine upon even the slightest impact, making the next set
of wheels you pilot will be a wheel chair. Many car builders in the
import scene with 4 door cars and harnesses make the mistake of mounting
to the floor behind the front seats because they still want to use the
back seat.
-----Original Message-----
From: owner-datsun-roadsters@autox.team.net
[mailto:owner-datsun-roadsters@autox.team.net] On Behalf Of alvin
gogineni
Sent: Thursday, September 19, 2002 7:49 PM
To: msedlack@neo.rr.com; Ofarrell.Fergus@hitco.com;
datsun-roadsters@autox.team.net
Subject: Seatbelt crazy
Thanks everyone for their input on the harness. I don't have a
definitive
answer yet. But I think it makes sense to mount the tab at or just
higher
than shoulder level. A friend of mine suggested mounting the tabs on the
rear trunk panel, not the shelf. Does this sound feasible, of course
with a
suitable backing plate on the trunk side?
If its safer to mount them at shoulder level, why does the famous Sora
Blue
racer have his harness point mounted on the shelf, well below shoulder
level? I'm confused.
>From: "Mark Sedlack" <msedlack@neo.rr.com>
>To: "alvin gogineni" <alvingogi@hotmail.com>,
><Ofarrell.Fergus@hitco.com>,
> <datsun-roadsters@autox.team.net>
>Subject: Re: Seatbelt update/solution
>Date: Thu, 19 Sep 2002 16:11:59 -0400
>
>Alvin,
>Harness anchor points will take a load of up to 5000 pounds
>instantaneous load ( 25G peak acceleration at 35mph DeltaV x 200lbs
>driver mass=load).
>
>This would be what could be seen in a 35MPH impact into a fixed barrier
>(i.e. bridge abutment). More modern cars will transmit less total G's
>to the occupant, due to the crush characteristics engineered into the
>vehicle chassis, but the Roadster has a rigid frame which terminates at
>the front of the vehicle.
>
>The loops shown in your photo are most probably not good enough steel
>to anchor a harness. I threw a picture up on my server
>http://home.neo.rr.com/mark2000/grant/Alvin1.jpg The two options
depicted
>are to replace one of the roll-bar mounting bolts with a longer, grade
8
>bolt and nut, ensuring that there is a sufficient doubler under the
body
>tub
>to distribute the loads.
>
>The other option is to have a certified welding shop weld a 3/16"
>mounting tab to the down tube on both sides of the bar to anchor the
>shoulder belts to, and again, make sure the bars mounting bolts have
>doublers underneath. I'm going to be taking this aproach on our custom.
>Most race car fab. shops will have both the certified welder and the
>tabs on the shelf.
>
>It is preferred to have the shoulder belt anchors at or above the
>height of the shoulders, and or not less than 1" below, in case the
>seat back structure would fail. Picture tying a slipknot loop around
>an orange and pulling it tight - if the seatback fails to support the
>shoulder belts that are anchored well below the shoulders, your body
>becomes the orange - compressive loading of the shoulder belts downward
>on your spine can ruin your whole day.
>
>Mark Sedlack
>OROC
>Cuyahoga Falls OH
>66 1600 http://home.neo.rr.com/mark2000/images/datsun1600/
>77 280Z http://home.neo.rr.com/mark2000/images/datsun1600/Z.htm
>
>----- Original Message -----
>From: "alvin gogineni" <alvingogi@hotmail.com>
>To: <Ofarrell.Fergus@hitco.com>; <datsun-roadsters@autox.team.net>
>Sent: Thursday, September 19, 2002 1:31 PM
>Subject: Seatbelt update/solution
>
>
> > I think I found a way to mount that shoulder harness, it will need
to be
> > reinforced too. There's a picture in www.picturetrail.com/alvin6
with
>the
> > setup in mind. Let me know what you guys think.
> >
> >
> > >From: "O'Farrell, Fergus" <Ofarrell.Fergus@hitco.com>
> > >To: "'alvin gogineni'" <alvingogi@hotmail.com>
> > >Subject: RE: seat belt mount option
> > >Date: Thu, 19 Sep 2002 09:57:52 -0700
> > >
> > >Hey Alvin,
> > >I am not sure if it was on the SummitRacing website or in the
> > >instructions/safety warnings for my 4-pt Diest harnesses, but they
> > >specifically said that if you have 4 or 3 points like ours, don't
> > >take
>the
> > >center strap over the seatback and down to the floor. you have to
> > >go
>back
> > >,
> > >not down.
> > >this is because when the body gets thrown forward, depending on how
> > >far from the belt attachment to the seat pivot, the belt will slide
> > >around the corner
> > >at the top of the seat, letting the body and seat move forward.
Kind
>of
> > >like a rope going around a pulley.
> > >
> > >Ya know what would work well but might be kinda unsightly in your
> > >nice clean interior, is instead of using a metal tang which bolts
> > >under the
>rollbar
> > >mount, you use a piece of wirerope and a carabiner swaged into the
> > >end. this would allow the belt to move all around, and transmit the
> > >load
>well.
> > >I
> > >am just not sure how to make it look as cool as the rest of your
>interior.
> > >
> > >still thinkin'
> > >Fergus O
> > >
> > >-----Original Message-----
> > >From: alvin gogineni [mailto:alvingogi@hotmail.com]
> > >Sent: Wednesday, September 18, 2002 5:07 PM
> > >To: Ofarrell.Fergus@hitco.com
> > >Subject: Re: seat belt mount option
> > >
> > >
> > >Yeah, I was upset when I put a pinhole in that area through the
> > >vinyl,
>only
> > >to find out I couldn't use it! My rollbar does mount in that area
> > >on
>the
> > >shelf, the pic isn't resized. There are mounting holes further back
> > >on
>the
> > >shelf? WE just drilled some holes to mount it. I will probably
> > >mount
>the
> > >the
> > >
> > >belt directly behind the seat on the shelf. Will have to use a
> > >metal
>plate
> > >to reinforce though. ARRGH!
> >
> >
> >
> >
> > _________________________________________________________________
> > Chat with friends online, try MSN Messenger:
> > http://messenger.msn.com
> >
> > /// datsun-roadsters@autox.team.net mailing list
> > /// Send admin requests to majordomo@autox.team.net or go to ///
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> >
> >
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