SoundGuyDave
This Space For Rent
- Joined
- Apr 9, 2007
- Posts
- 1,978
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- 28
Funny you should mention the MM piece... Another S197 open-tracker and I were discussing that in light of the Hallet crash, and, playing "devil's advocate," came up with two fairly important issues with that bar.
1) mounting location may be too far rearward for many drivers to set up the seat properly and still have any real protection. With the Autopower bar, I have nearly 10" of clearance between my helmet and the plane of the hoop, and that bar is set almost 3" further forward than the MM hoop location. Forget about the "gansta lean" seating position: you need to be able to go flat to the floor with your feet, and drape each wrist across the top of the wheel without pulling your shoulder off the seat. Unless you're 6'4" or better, your seat will NOT be all the way back. With mine, I have barely enough room to slide my thigh between the wheel and the seat side bolster, and I'm a 5'11" bean pole.
2) There is NO diagonal brace on that hoop design. This is a deal-breaker for the road-race sanctioning bodies. NASA (and IIRC SCCA) require that any safety equipment that is installed in a non-competition (HPDE or TT) car must meet the specs laid out in the relevant section of the competition CCR. That means positioning, design, materials, installation, etc. ALL road-race tech bibles that I've seen require a diagonal brace, but oddly NHRA calls them "illegal," for some reason that is beyond my imagination. If you look at the design of the optional (swing-out!!) door bar, the MM bar is being sold as a drag "cage," and not for road-racing.
In terms of crash protection, let's look at the main, common types of "very abrupt stops."
Nose-in: the harness bar in the main hoop locks the driver into the seat through the harness straps.
Tail-in: the harness bar in the main hoop is the mounting point for the seatback brace, which prevents the seat from folding.
side-impact: The diagonal siffens the rectangular shape of the main hoop, preventing any shifting that would allow the body structure to roll into the driver's area.
rollover, from side: Same as above, but the overall hoop and diagonal act as a pair of triangles (four if your harness bar is integrated), to keep the hoop's shape in the event of a rolling finish, as in "you tried to save it, and went off sideways."
Top impact: Like the Hallet crash, the diagonal would serve to keep the hoop shape rigid, and if it was properly boxed to the frame, probably wouldn't have punched downwards through the floor.
With the crash in question, I'm not overly optimistic that ANYTHING short of a full, triangulated cage would have kept the roof structure up, especially if it was gutted like I suspect it was.
1) mounting location may be too far rearward for many drivers to set up the seat properly and still have any real protection. With the Autopower bar, I have nearly 10" of clearance between my helmet and the plane of the hoop, and that bar is set almost 3" further forward than the MM hoop location. Forget about the "gansta lean" seating position: you need to be able to go flat to the floor with your feet, and drape each wrist across the top of the wheel without pulling your shoulder off the seat. Unless you're 6'4" or better, your seat will NOT be all the way back. With mine, I have barely enough room to slide my thigh between the wheel and the seat side bolster, and I'm a 5'11" bean pole.
2) There is NO diagonal brace on that hoop design. This is a deal-breaker for the road-race sanctioning bodies. NASA (and IIRC SCCA) require that any safety equipment that is installed in a non-competition (HPDE or TT) car must meet the specs laid out in the relevant section of the competition CCR. That means positioning, design, materials, installation, etc. ALL road-race tech bibles that I've seen require a diagonal brace, but oddly NHRA calls them "illegal," for some reason that is beyond my imagination. If you look at the design of the optional (swing-out!!) door bar, the MM bar is being sold as a drag "cage," and not for road-racing.
In terms of crash protection, let's look at the main, common types of "very abrupt stops."
Nose-in: the harness bar in the main hoop locks the driver into the seat through the harness straps.
Tail-in: the harness bar in the main hoop is the mounting point for the seatback brace, which prevents the seat from folding.
side-impact: The diagonal siffens the rectangular shape of the main hoop, preventing any shifting that would allow the body structure to roll into the driver's area.
rollover, from side: Same as above, but the overall hoop and diagonal act as a pair of triangles (four if your harness bar is integrated), to keep the hoop's shape in the event of a rolling finish, as in "you tried to save it, and went off sideways."
Top impact: Like the Hallet crash, the diagonal would serve to keep the hoop shape rigid, and if it was properly boxed to the frame, probably wouldn't have punched downwards through the floor.
With the crash in question, I'm not overly optimistic that ANYTHING short of a full, triangulated cage would have kept the roof structure up, especially if it was gutted like I suspect it was.