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I'm making my own harness bar. As I look through all the different designs made (BK SharkBar and the old HardBar) for the C5 I paid attention to where the bar sits vertically in relation to race seats and shoulder strap angles for a 5 point.
I just recently installed a Corbeau Forza seat using a Corbeau seat bracket (w/dual locking sliders). I'm seeing that if I make a bar like the old Hardbar that mounts as high as the OEM seat belt bolt, the shoulder straps will angle UPWARD after they pass through the seat. I'm 6' tall and my shoulders are at the same height as the seat-back holes
My plan is to make some flat plate/end caps that can allow the bar to be lowered (similar to how the BK SharkBar does this but with a bend in the tube).
Looking up shoulder belt angles, I see the range of 0* (horizontal) to -20* (downward angle) is OK with 10* downward being optimal. It strikes me odd how the old Hardbar was so accepted with it being mounted so high behind the seat. If I had to guess, the OEM seat belt bolt is a good couple of inches ABOVE my seat-back holes.
Opinions welcome! (before anyone argues, I can get a whole harness bar made for cost of materials...<$50 and a days work...and only locally autocross. If I was an avid Road Racer I would be hesitant to home brew something like this.)
Agree. I don't know that seat or that bar. I have the BK Auto harness bar. This design has the bar a couple of inches below the mounting bolt. With my Corbeau A4 seats a bar level with the bolt would be way too high. The A4s recline and I put on a significant recline to get my head with helmet below the roof.
nasa says no more than 20 degrees...."The shoulder harness should be mounted behind the driver and above a line drawn downward from the shoulder point at an angle of no more than twenty (20) degrees with the horizontal"
Thanks guys. For my seat (Corbeau Forza mounted on Cobeau bracket with dual locking sliders) that puts the bar about 4.5" from the top of the hump behind the seats. I have drop down end-plates and the bar welded, but it will just swing (no gusset legs going to seat frames yet.
The issue I did not expect was side to side movement of the bar...so no I need to figure out some spacers to eliminate the side to side. I'm keeping the stock bolts as well since I can't find any info on what the thread pitch is for the shoulder bolt hole. I would say M12x1.75 but not quite...A die does not work on the stock bolts and a new M12 bolt will not thread into the pillar. I even tried a 1/2-13 and it didn't inspire confidence in me lol.
Tangent to your shoulder height is best practice. I work for a harness company and have witnessed 100+ crash tests. When you start to drop the mounting lower than shoulder height, you will start to see spinal compression in frontal impacts. Hope that helps.
Well...I don't think the DIY bar will work out to my liking....
Looking into pre-made setups. Does anyone know if the Brey Krause bar sits LOWER than the stock shoulder bolt height in a C5? It looks like the SharkBar from VetteWorks sits low enough and Ridetech version also seems to sit low enough but I don't want to cut my interior panels.
I'm not familiar with any other company offering bolt in harness bars except the three mentioned above? I know of a used HardBar but 1) No longer in production 2) It bolts in way too high using stock shoulder belt location.
The one thing I didn't foresee is the side to side movement of the bar when installed. So I started to make spacers and given the tolerances I could hold in my garage with hand tools I wasn't too happy with the final fitment etc. The B pillars are at a compound angle in relation a true "cross car" plane which the harness bar would be. My design was very similar to the SharkBar in terms of how the end plates offset the bar lower...the Sharkbar has a bend in the bar itself.
I left it with still needing to make the gusset legs that connect down to the front seats, buy or make tabs to attach rod ends and final weld everything.
I started to question the safety aspect of it if I ever get on the road course and that I didn't design it right. Some things are worth going with a proven design and a nice bolt in.
Here is a pic of the BK bar installed. The bar is a couple inches below the factory seat belt mount. With some cutting of the seat mounting bar and welding you could lower it even more.
Great picture. That is lower than expected. What seat os that? Looks like a Corbeau something. The shoulder holes look level with the bar (a good thig).
I have a Corbeau Forza on a Corbeau dual locking slider ( me tioning for height of shoukder holes)
Great picture. That is lower than expected. What seat os that? Looks like a Corbeau something. The shoulder holes look level with the bar (a good thig).
I have a Corbeau Forza on a Corbeau dual locking slider ( me tioning for height of shoukder holes)
Yes that is an A4 seat, not shaved on their slider. I need to recline it a bit to keep my helmet off the roof.
I seem to come across A LOT more BK bars for sale than ShakBars...Is a BK bar better in some way than the SharkBars? Or is there something I am missing?
I honestly like the look of the SharkBar better as it's cleaner install, but from a functional standpoint I'm curious.
Last edited by smitty2919; 02-07-2019 at 11:10 AM.
Well, case closed. Found a second hand SharkBar NIB online. Install went OK however I'm not a fan of the mounting bolts to the pillar and how the OEM seat belts are not free to rotate.
May need to make some tweaks and source a longer bolt to use a sleeve to allow seat belt to rotate.
11-30-2018, 04:00 PM
Harness bar height
