Wow. Don't blink.
K
In all fairness to the Mee-Otter, I don't know that I would have done any better...yes, that hurt to write, but I'll be OK...
It looked like he had time to slow way down, so the impact was less than 50mph even.
Too bad he tried to follow the first car through instead of heading for where the spinning car had been.
IMO this certainly proves the gross inadequacy of the simple X door bar design!
Last edited by Racer Chris; 09-30-2008 at 02:29 PM. Reason: typed wrong word by accident
I had to add to that statement. As Greg stated earlier, the tubes will be put in tension if the X is formed in a single plane. They can be designed and built better. For the passenger side of the car, I honestly don't think it needs to be bomb proof. There is a lot of room between that door and the driver. If you have to add ballast to make weight...it is a good place to put it though...
After looking at that video, one has to ask. If that hit were on the driver's side, and let's say the side impact protection was two complete "parallel" bars with maybe three vertical stringers tying them together, would the driver have come out unhurt?
Racin deal. Zigged when he should have zagged.
Steve Linn | Fins Up Racing | #6 ITA Sentra SE-R | www.indyscca.org
comments please. this would be fore a miata, with main hoop mounted on the package shelf, and the proportions aren't exactly right in my little drawing. i don't think the distance from the rearward stringer to the main hoop would be that far.
bold lines indicate attachment/welding points.
Travis Nordwald
1996 ITA Miata
KC Region
A good idea, leaving plenty of space for a 6-foot + driver:
http://www.kakashiracing.com/images/DSCN3703.JPG
http://www.kakashiracing.com/images/DSCN3702.JPG
http://www.kakashiracing.com/forsale/sm.html
Last edited by Greg Amy; 09-30-2008 at 03:25 PM.
or 6'3'' driver.
any reason you chose to go in front of the dash with the a-pillar bar?
Travis Nordwald
1996 ITA Miata
KC Region
Travis - the cage Chris put in my car attaches at the front of the car in a fashion very similar to what you describe. As you probably know, dash removal is not that difficult. (Though I freely admit I paid Chris to do that for me as well.) The advantages are increased access area - the downtubes on mine are right in line with the dead pedal on the driver's side. The only downside is that the fuse box approaches "genuinely insane" in terms of access, but it is worth it in my eyes.
Remember, not too long ago there was a debate about the forward attachment points (at least in the northeast) and whether it was legal to attach them to the brace that runs behind the dash. Ultimately this was ruled illegal - search over at the Daniels website on the subject and I think DDG may have been involved. (I know you can't post and ask over there! )
Hero To The Momentum Challenged
A cage like yours is what started a huge debate on other sites about door bars. Cars were sent home because the door bar did not connect the main hoop and down tube. My read is that a tube that goes to the attachment point for required element is same as going to that tube. The lower tube in the door counts as a seperate attachment point unless you stretch the plate for the main hoop down the allowed 15 inches. Not something you should get grief over but it is not "technically" legal. I had a car come through with your style cage and we added a short piece of tube from the lower bar to the hoop. Rules do not say "continuous" door bar.
Steve Eckerich
ITS 18 Speedsource RX7
ITR RX8 (under construction)
Travis,
I believe as well that your design would not be legal, nor would I think that would be a safer alternative. I believe the way to the strongest intrusion protection would be to have your door bars attached to the main hoop and a-pillar. As it sits now the door bar is attached to sheet metal at the rear. Think monocoque here!! I also would not do a main hoop on that parcel shelf. Drivers side impact at rear wheel and there is nothing preventing a left rear tire from being punched into your kidney etc. or the whole car coming through. Again, try to think monocoque. The high main hoop route starts protection 2 1/2 feet off the ground and your sitting under it. Where most bumpers are flying around. Honestly if you don't fit with a safe cage try a different car. I'm 6'4" so I'm in familiar situations.
Chris Leone
318i going STL!!!
E36 ITS underconstruction(sold)
84 944 ITS (sold)
71 240z more than half way there/now GT2 bound!!
ChrisLeonemotorsports.com
Roll cages and fabrication
meh. i never had to get at it once in the 5 years i had my last car. i'm not too concerned about that.
you mean that stock tube that runs behind the dash? i wasn't planning on attaching to it, but replace it. not sure if IT and SM rules differ here, but i thought that was legal. no, i don't remember the debate, and i can't search on that site either. not that that site has much of anything useful going on anymore anyway.....Remember, not too long ago there was a debate about the forward attachment points (at least in the northeast) and whether it was legal to attach them to the brace that runs behind the dash. Ultimately this was ruled illegal - search over at the Daniels website on the subject and I think DDG may have been involved. (I know you can't post and ask over there! )
Travis Nordwald
1996 ITA Miata
KC Region
that's a good idea steve. with the 'X' bar design i feel like it leaves a rather large "gap" down at the bottom of the door by the rocker. that straight piece of bar with the separate attachment point was just my attempt at solving that.
i'm thinking your statement about "a tube that goes to the attachment point for a required element is same as going to that tube" is in reference to the bottom of the two 'X' bars, or the middle of the three? others have interpreted the rules in the same way, as the NASCAR bars in my last car had the upper tube attached to the main hoop itself, and the lower bar was attached to the plate that the main hoop was attached to.
were either one of these drawings how you "solved" that problem?
Travis Nordwald
1996 ITA Miata
KC Region
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i'm no engineer, so i don't know how well i could argue that attachment at the package shelf is equally as safe as at the "rocker." all i know is that it's where my last cage was attached, where Greg's was attached, and where countless other miata cages are attached. i can't see how it's any worse than the flat plates that mount strictly to the floor pan up front (also legal).
i also know that my car suffered about the largest rearward impact you can have in a miata, with the cage attached at the parcel shelf, and faired pretty well. i think the tire was knocked into the back of the seat, but changing the location of the main hoop wouldn't have prevented it.
Travis Nordwald
1996 ITA Miata
KC Region
Travis... with the 144" & 15" long rule, you can get all the way down to the corner brace from the package shelf with sq.in. to spare. There's a mass of structure in that whole area.
Also, ideally you want the A pillar brace to head to the node down at the front pad... sometimes you have to depart from the ideal to make things work, but you have some room there... basically you're duplicating the down bar in tGA's Miata cage.
I don't think that eliminating the dash tube is legal at all but that's a different thread
Scott Rhea
Izzy's Custom Cages
It's not what you build... It's how you build it
Performance Driven LLC
Neon Racing Springs
you're right scott.....i guess i'd be just adding a dash bar rather than replacing one.
Travis Nordwald
1996 ITA Miata
KC Region
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