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Thread: Harness bar install...

  1. #1

    Default Harness bar install...

    I thought the harness bar install would be a piece of cake... but I can't get the spacer out from under the seatbet mounting bracket on the driver's side. I tried to pry it out to no avail. I'm guessing the only to get it out is to loosen the mounting bolts to the rollbar itself... I'd really rather not mess with that but I'm not sure there is another way.

    In a related note, if anyone has any tips for putting in the eye bolts for the harnesses I'm all ears. A friend said I should mount the sub belt bolt to the raised portion of the floor that runs across the car (the part that the seat bolts to if that makes any sense). Then you use a hole saw to cut a hole on the back side of that raised portion to access the bolt to secure it to the car. Bad idea?
    SOLD - '91 BRG
    SOLD -'99 Signal Green
    Looking for my next car...

  2. #2

    Default

    I just drilled a hole behind that raised portion, outside of the frame rail, then bolted the thing in with two big flat washers on either side of the floor to keep it from tearing through.
    '94 Black & Black & Tan
    '99 head swap, JR header, TDR intake & header blanket, MegaSquirt, RB hollow bar, Tein Flex, 15x8 6ULs, HD M2 Sport, FM cat, Borla cat-back, black '95M interior, MOMO Zebrano, IL Motorsport console...

    Dyno Days
    8/16/08 (bone stock): 103.1 hp/99.0 lb-ft - Dynojet
    8/23/08 (Borla cat-back): 108.2 hp/104.1 lb-ft - Dynojet
    8/13/11 (more stuff...): 126 hp/116 lb-ft - Mustang dyno

    Roger Moore: the Danny White of James Bonds

  3. #3

    Default

    Why behind? Just so you can't see it or is that where it needs to be? I don't want to screw it up :)
    SOLD - '91 BRG
    SOLD -'99 Signal Green
    Looking for my next car...

  4. #4

    Default

    Behind so it's out of the way and out of sight. Believe me, it's very much an "eyeball it and drill" process.
    '94 Black & Black & Tan
    '99 head swap, JR header, TDR intake & header blanket, MegaSquirt, RB hollow bar, Tein Flex, 15x8 6ULs, HD M2 Sport, FM cat, Borla cat-back, black '95M interior, MOMO Zebrano, IL Motorsport console...

    Dyno Days
    8/16/08 (bone stock): 103.1 hp/99.0 lb-ft - Dynojet
    8/23/08 (Borla cat-back): 108.2 hp/104.1 lb-ft - Dynojet
    8/13/11 (more stuff...): 126 hp/116 lb-ft - Mustang dyno

    Roger Moore: the Danny White of James Bonds

  5. #5

    Default

    The sub belt needs to be fastened to the floor aft of the pass-through hole in the seat, so the best position is relative to where your seat is mounted. Mine's 5-6 inches behind the front seat mounting rail outboard of the frame rail under the car. Make sure the eye bolt doesn't extend down further under the tub than the frame rail or there's a chance it will catch on something - use nuts and (2.5"?) fender washers both inside and outside.

    The sub belt under tension wants to be shaped like > or ) instead of \ as a straight line will deflect much more than the curved belts will stretch given the same amount of force. If your hips are allowed to travel too far forward, the lap belts will rise above your pelvis and hold you by your gut. Not good.

    Chris

  6. #6

    Default

    Question about using those washers.

    Saw on a TV program once that using the same size washers on either side of the sheet metal was a bad idea. Reason being is that if they are the same size, in an accident, they can still rip through the sheet metal. But using 2 different sized washers reduces that possibility because the stress is in 2 different locations, rather than in identical locations on both sides of the sheet metal.

    Thoughts?
    If you're addicted to cold turkey how do you stop?

    I reject your reality and substitute my own.

  7. #7
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    Default

    I was remembering that you want more than a washer, but a quick google says that I might be remembering for the lap belts you need a backing plate.

    Gary @ TrackDog has an eyebolt kit... (http://www.trackdogracing.com/websit...ield.htm#floor) I bet if you asked really nicely he could tell you where to put it safely seeing as he's done it a few times before

  8. #8

    Default

    I'd think the more surface area under the washers the better since the load will be spread more, there's more material between the washers for friction and metal deflection and the shearing forces against the tub would be reduced. I wouldn't willfully make one washer smaller than the other to try to address the point you raised, but that's not to say that what was said about metal shearing isn't correct.

    If you do go with different sizes, put the big washer on the outside of the tub - the forces the system is designed for will be pulling against it and it will spread the load more.

    And as a late thought, any forces applied to the bolt will result in it wanting to twist/rotate in the direction of pull since the installation isn't linear - you'll get pulling forces aft of the centerline of the mounting point as well as pushing forces forward of it as it tries to rotate to a linear pull. The twisting energy will find the weakest point and exploit that to total failure. I'd think a pushing force with a smaller washer would require less energy to put the initial slice in the tub and once that's started total failure would be somewhat easy to achieve. (Mental image is from drinking beer high school - crush a can flat and try to tear it in half - very difficult - nick an edge and it'll tear like paper.)

    Chris

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