how to prevent harness spread??
04-14-2010, 07:46 AM
#31
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04-14-2010, 12:11 PM
#32
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for a large Hans Z = 10"(per Schroth, x = ~10"
so using that formula Y looks to be ~ 5" OC, roughly what I'm shooting for, the belts seems to naturally want to spread to ~ 8 - 9"
I do have some SFI padding coming, so just zip tie to the cross bar instead of the collars? I wonder what the magnitude of the spreading force is?
so using that formula Y looks to be ~ 5" OC, roughly what I'm shooting for, the belts seems to naturally want to spread to ~ 8 - 9"
I do have some SFI padding coming, so just zip tie to the cross bar instead of the collars? I wonder what the magnitude of the spreading force is?
04-14-2010, 02:04 PM
#33
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As for keeping the belts in place, padding and zip ties will not do. This setup is fine if you are sitting still or not intending to hit anything when moving (doink!) but will do nothing to counter any truly dynamic situations where you're getting thousands-of-pounds of load. In other words... DUH! You need the solid shaft collars to keep things in place.
40g seems to be about the benchmark figure when crash biomechanisists discuss forces and figures, and throw out numbers for comparison. At that level of stress, the shoulder harnesses can see upwards of 1500lbs EACH in load. If you feel that some plastic cable ties and foam is capable of countering that level of potential successfully, then I guess you are all set.
04-14-2010, 02:53 PM
#34
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OK... I'll try this again;
40g seems to be about the benchmark figure when crash biomechanisists discuss forces and figures, and throw out numbers for comparison. At that level of stress, the shoulder harnesses can see upwards of 1500lbs EACH in load. If you feel that some plastic cable ties and foam is capable of countering that level of potential successfully, then I guess you are all set.
40g seems to be about the benchmark figure when crash biomechanisists discuss forces and figures, and throw out numbers for comparison. At that level of stress, the shoulder harnesses can see upwards of 1500lbs EACH in load. If you feel that some plastic cable ties and foam is capable of countering that level of potential successfully, then I guess you are all set.
04-14-2010, 09:04 PM
#36
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I don't think you've solved the issue. The colars are not holding the belts in the corect posistion. It looks like the chaffing tape is doing the holding in place and maintaining proper spacing. I sugest you nix the tape and move the colars up agains the belts on the outside and install however many colars necessary in between the belts to maintain the correct spacing.
04-14-2010, 11:37 PM
#37
04-15-2010, 09:43 AM
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04-15-2010, 09:54 AM
#39
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I'm not sure you have either;
The goal is to get as close to the spacing that Schroth suggests, and the belts should rest against the collars. In your case, if the seat holes are too far apart, you must consider not allowing it to unduly infringe on the belt paths (a little is OK). You also must consider the setup in light of the belts being on the HANS, not just everything in a static state. It's kind of hard to strap in and get a photo without an assistant, but that is what you need to prove it all to us railbirds.
You may find that you have better seat hole clearance than you think, even at a narrow distance apart.
I don't think the tape will hurt, but I would not have any of it between the belt/bar interface. Some on the edges of the collars might give you evidence for/against your chafing theory.
The goal is to get as close to the spacing that Schroth suggests, and the belts should rest against the collars. In your case, if the seat holes are too far apart, you must consider not allowing it to unduly infringe on the belt paths (a little is OK). You also must consider the setup in light of the belts being on the HANS, not just everything in a static state. It's kind of hard to strap in and get a photo without an assistant, but that is what you need to prove it all to us railbirds.
You may find that you have better seat hole clearance than you think, even at a narrow distance apart.I don't think the tape will hurt, but I would not have any of it between the belt/bar interface. Some on the edges of the collars might give you evidence for/against your chafing theory.
04-15-2010, 01:50 PM
#41
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Larry Herman
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
04-15-2010, 09:50 PM
#45
Before my seats came, I had 6 point Sabelt and a Techequipment roll bar.
Since I had sport seats without belt holes I just bought some soft 3/4" nylon mountain climbing webbing and tied a loop through the left and right strap so they could only spread 4" apart.
It weighed nothing.
Nylon could do no damage to nylon.
It cost $0.25 per foot = $0.50
Ask a Boy Scout to tie a good knot for you.
Since I had sport seats without belt holes I just bought some soft 3/4" nylon mountain climbing webbing and tied a loop through the left and right strap so they could only spread 4" apart.
It weighed nothing.
Nylon could do no damage to nylon.
It cost $0.25 per foot = $0.50
Ask a Boy Scout to tie a good knot for you.