i installed an autopower 4pt bolt-in race rollbar last night in my hatch. after seeing how thin the floor panels and the wheel wells are, i'm second guessing whether or not i want to mount my harnesses directly to the harness bar..... like this:




it just seems to me that in a head on collision, all the force of the driver moving forward will be pulling mostly on the rear supports of the rollbar, which are only held to the uni-body by 1/16" sheet metal and 3"sq plates.

am i just being too paranoid and should i just mount my 5pt like above? or should i keep the shoulder belts bolted to the rear OEM belt locations and just loop them over the harness bar to avoid spinal compression???

thoughts?

 

I think that's fine, but if you want added safety, have a sheet-metal yard cut you some bigger back plates to go under the unibody. Or, if you don't mind re-installing the bar, you could have somebody weld bigger plates to the feet of the mainhoop in addition to larger plates underneath.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crack Monkey &raquo;</TD></TR><TR><TD CLASS="quote">you could have somebody weld bigger plates to the feet of the mainhoop in addition to larger plates underneath.</TD></TR></TABLE>

i'll look into that. thanks

who is really questioning whether he should have gone with kirk

 

This is a good question. I have never heard of the rear supports being pulled forward in a head-on impact. The only force being placed on the main hoop in the forward direction (other than momentum) would be from the driver's body. I would doubt that you carry enough momentum in your upper body to pull the backing plates through the body of the car. If you just had the bolts through the holes, you could certainly pull them through, but that backing plate has a goo deal of surface area and you would have to tear a HUGE hole in the body to pull it through.

 

I would suspect that your torso would pass through the harness (happens in plane crashes... ) before the bar mounting plate came through the floor....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">I would suspect that your torso would pass through the harness (happens in plane crashes... )</TD></TR></TABLE>

hmm.... bad visual i'll try to avoid that one

 

increasing the lengt of the shoulder belts would cause more elongation/stretch in case of a head on collision strong enough the rear mounts would come loose. i tihnk the best solution to ease your mind is make a bigger/thicker backing plate, and perhaps weld it to the backside, then drill it thru.

or just weld it in.

 

just another data point....

http://www.corner-carvers.com/...14049

 

I wouldn't opt for using the stock seatbelt mounts....
spinal compression
you've got a nice rollbar with a harness bar....so use it!

as everyone else stated...see if you can't get something "rigged-up"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">just another data point....</TD></TR></TABLE>

for a convertible...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">for a convertible...</TD></TR></TABLE>

Which makes it even more valid... no roof structure to aid the rollbar from doing its job.

 

and no diagonal...making the hoop "weaker", but it still held up fine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elgorey &raquo;</TD></TR><TR><TD CLASS="quote">and no diagonal...making the hoop "weaker", but it still held up fine.</TD></TR></TABLE>

But at less than highway speeds probably.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by maxQ &raquo;</TD></TR><TR><TD CLASS="quote">But at less than highway speeds probably. </TD></TR></TABLE>

In a car much heavier than what we're probably driving.

Like i said, just another data point.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DOHCDX &raquo;</TD></TR><TR><TD CLASS="quote"> who is really questioning whether he should have gone with kirk </TD></TR></TABLE>

Would it really make that much of a difference? I know that people installing the Kirk roll bar in myself are still having reinforcement plates intalled (myself included, anyone want to help me out? ).

 

i thought the rear support bars on the kirk design go all the way back and mount to the frame rails behind the fuel cell

 

It's possible, but that I don't know. I do know that Kirk will make basic custom modifications to the design of your bar without charging much more...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DOHCDX &raquo;</TD></TR><TR><TD CLASS="quote">i thought the rear support bars on the kirk design go all the way back and mount to the frame rails behind the fuel cell</TD></TR></TABLE>

That's how mine is connected in the rear.

 

The KIRK rollbars and cages for the CRX all have the rear supports going to the rear floor pans. Another thing-the generally accepted method of installation for the harness is on the crossbar. The reason as noted is to keep it a reasonably short length and to properly position it. Take a look at the diagram in the Simpson catalog or the GCR.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">I would suspect that your torso would pass through the harness (happens in plane crashes... </TD></TR></TABLE>

Yeah - like seat belts in airplanes are ever going to do much good. Add them to the list of feel-good safety features on commercial airplanes:

"...and in the event of a water landing, the cushions of your seat will serve as a debris field to show the news choppers where you were turned into fish food."

K

 

thats why when theres a loss of cabin pressure they feed you oxygen.....pure oxygen. to get you high


Modified by Lo-Buck EF at 12:27 AM 1/14/2004

 

Fantastic movie. I just wish I could get my hands on one of those safety manuals with the people screaming and pushing the children out of the way...