Hans Devices and DE
#76
Originally Posted by fatbillybob
Geo,
I don't think the stick pointed at your spine with a back brace is any worse than the stick of the steering wheel pointed at your chest. In fact we are probably more likely to get hit by that than the back brace. Distribution of load is the key so if the PCA etc say 30 square inches 12 square inces of plate on the back brace pole or whatever there should be enough distribution. You can always have more square inches. Also, if a properly designed cage with seat bolted to cage and cage features like seat rails that go from the base up to the harness bar the seat can deform less under your conditions regardless if it is plastic or metal as it is supported along its entire length from seat leading edge to shoulders. Is your beef with back braces not really the concept of seat back bracing but really with the way back braces are made/installed today for non-pro racers as an "add on" device with zero testing?
I don't think the stick pointed at your spine with a back brace is any worse than the stick of the steering wheel pointed at your chest. In fact we are probably more likely to get hit by that than the back brace. Distribution of load is the key so if the PCA etc say 30 square inches 12 square inces of plate on the back brace pole or whatever there should be enough distribution. You can always have more square inches. Also, if a properly designed cage with seat bolted to cage and cage features like seat rails that go from the base up to the harness bar the seat can deform less under your conditions regardless if it is plastic or metal as it is supported along its entire length from seat leading edge to shoulders. Is your beef with back braces not really the concept of seat back bracing but really with the way back braces are made/installed today for non-pro racers as an "add on" device with zero testing?
2) My beef with back breakers is that they are pointed at my spine. And the fact that IMHO a seat that is not rigidly mounted will transfer less energy to the driver in a crash.
#77
I think the bottom line is that you have to take safety seriously, non-pca clubs are not as safe in my opinion, one group had the honor system for tech, there were a lot of dishnorable guys that day.
If a hans makes you feel safer get it. Years ago when I was class racing they had a rule about driveshaft safety loops. Well, I snapped a driveshaft at 137mph, that shaft would have decappitated me if not for that steel hoop as it easily ripped through the aluminum floor panels.
Safety first, I think I'll put the DAS bar in mine.
If a hans makes you feel safer get it. Years ago when I was class racing they had a rule about driveshaft safety loops. Well, I snapped a driveshaft at 137mph, that shaft would have decappitated me if not for that steel hoop as it easily ripped through the aluminum floor panels.
Safety first, I think I'll put the DAS bar in mine.
#78
Originally Posted by C4S Surgeon
I think the bottom line is that you have to take safety seriously, non-pca clubs are not as safe in my opinion...
Better than some perhaps, but not all.
#79
Originally Posted by Phokaioglaukos
Agree that a cage is only safe with a helmet, but I thought a roll bar (like the DAS bar) was fine when driving on the street without a helmet. What am I missing?
Of course it is a matter of degrees. If you are short and a long way from the hoop, if your seat is very stout in makeup and mount, and you don't get hit that hard, you might be fine. If any one of these go against you, you might get more than your bell rung!
It is NOT a universal problem, but it is DEFINITELY something you must take into account when making your decisions.
#80
What certifications?
For Larry and other instructors who may spend as much time in other people's cars as their own at a DE, I can see that the HANS (Hubbard/Downing) is not attractive--it can only be in a properly prepared car. (There is a FIA spec sheet in Acrobat format HERE.) For my car, though, I can set up the HANS correctly, and I won't be riding in other people's cars for some years.
I note that only the HANS is FIA approved. It's also SFI 38.1 certified. The SFI web site seems to be down now, but it should come back up HERE .
I guess the whole HANS setup is more expensive than a R3, but it has been in the market longer and I can set my car to use it properly. Thoughts on how to go?
I note that only the HANS is FIA approved. It's also SFI 38.1 certified. The SFI web site seems to be down now, but it should come back up HERE .
I guess the whole HANS setup is more expensive than a R3, but it has been in the market longer and I can set my car to use it properly. Thoughts on how to go?
#81
Originally Posted by TD in DC
John, My Kirkey seat has yet to be installed (I was trying to get the 944 ready for a DE tomorrow, but it will not be ready). I can probably return it for an Ultrashield. Which Ultrashield did you get, and do you have any advice on how I should mount it in my '84 944? Is the mounting hardware fabbed, or is there something else I should buy. TD
Mounting a seat is a real brain teaser.
First you need the positioning worked out. On top of my list is getting leg room worked out first. Then see if you can get the arm reach down right from there. This is where the Kirkey road race seats fail because of what I offered before.
Once that is worked out, syou need to allow for some re-adjustment in your mounting design because invariably what you think works sitting still in the shop will prove less than optimal in battle. You'll need to give yourself the chance to alter the setup with clever design.
Next, the mounting. I like alloy seats because they offer lots of options for mounting. I use a side mounting method like below. You can either do sliders or solid mount. I make side plates and bolt through the side panel for a very solid mount. You can also make your mount flanges large for multiple holes to fine tune your seat setup (see above).
I have landed on the concept of first attaching the two seat rails together (if using sliders) with a piece of 1.5x.125 angle iron welded to the sliders front and rear to form a square. It can sometimes be easier to use seperate tabs for mounting each corner because welding a bar across the two sliders front and back makes it a little trickier to keep the sliders parallel to eachother so they will slide easilly.
Then, I make pieces that these two cross members will sit on/in. Whether you need more headroom governs whether I set inside these mount rails or on top of them (as pictured). These mount rails are made of the same angle iron, and run across the floor from side sill to tunnel and weld on both sides and also various spots across the floor pan. 944s & 928s require you to section around the e-brake mechanism, which requiures more work.
Nuts are welded on the back of these beams corresponding to holes in the seat rail crossmembers. I use minimum 8mm fasteners, often prefering 10mm for serious track cars.
This all makes for a fairly simple and very stout mounting system that is not horrendously difficult to render.
Here is one I did in a 911 to give you an idea of what the floor rail look like. The seat rails then sit on top of this.
Does any of this make ANY sense?
#82
Originally Posted by fatbillybob
Redlineman, What is the "proper" angle of the seatbase to the floor?
#83
Originally Posted by Phokaioglaukos
I guess the whole HANS setup is more expensive than a R3, but it has been in the market longer and I can set my car to use it properly. Thoughts on how to go?
#86
Originally Posted by Geo
That's a pretty parochial statement.
Better than some perhaps, but not all.
Better than some perhaps, but not all.
I don't think they are all bad, pda runs a good one , but I think I'll stick with the pca events, jmo.
#87
Originally Posted by C4S Surgeon
Parochial, maybe, but from the many non pca de's I've done that's the conclusion I find.
#88
Originally Posted by Phokaioglaukos
The Isaac web site does not describe mounting the unit to the car/seat, so far as I can see. Does the non-helmet end just attach to shoulder belts?
It is NOT firmly attached to the belts....this was discussed a year or so ago in a very long thread....I'll try and find it.
Here are a few pics:
http://www.isaacdirect.com/images/Pr...m/RearView.JPG
http://www.isaacdirect.com/images/Pr...em/IsoView.JPG
#89
Originally Posted by adrial
Anybody have any pictures of the Isaac Link (their new, cheap device)?
http://www.isaacdirect.com/images/Pr...k/SideView.jpg
#90
Originally Posted by Phokaioglaukos
I note that only the HANS is FIA approved.
To me, these approvals/certifications mean absolutely nothing, especially given the history of the HANS and the FIA.