Pictures of Autopower Roll Bar?

[chrish900]

Does anyone have a picture of an Autopower (race) roll bar in a 2003-2004 Term coupe? IO-port has some photos of the bar in a vert, but I want to see how it fits in a coupe. I know there was a thread on roll bars about a year ago, but what is the feeling regarding a bolt-in? Do they punch through the floorboards in a roll over? Is it worth enlarging the feet? I like the ability to remove the diagonal and harness bars with the Autopower when not O/T. I'm still trying to decide on a bolt-in or having Piper Motorsports build a bar.

 

[sprint200]

Here are some pictures of an AutoPower Roll Bar In Action

I saw this incident personally and am now trying to figure out what to do with my own AutoPuncher roll bar to make it safe.

FWIW I had been told by a fellow OT enthusiast that he had seen the same thing with an SN95 two years earlier.........so there's apparently no difference between the old and the new.

My $.02; have one built properly.............:beer:

 

[MFE]

Regarding failures, I think it's fair to note that Autopower bolt-in 4-points have held up admirably well in some relatively spectacular rollovers, where I'd rather have had one than nothing at all.

That said, the possibility of punching through the floor bothered me enough after using one of these bars for 5 years that last spring, I added some reinforcement to the floorpan, tying them into the portion that creates the riser for the rear seat. That way the forces are distributed on two planes. So here's what I added to the main hoop mounting points. The 3 bolts in the center of this picture are where the holes are for the pads on the Autopower.

I profess no more scientific rigor than "that looks like it has to be better", but I did use heavier steel than the floor of the car is made of, and I specifically tied it into the upright portion for the rear seat. It also overlaps where the subframe connector runs under the body. The panel is bolted, obviously, but I also bonded it with adhesive that you can't see under the metal.

Looking straight down, facing the rear of the car on the drivers side:

 

[David Hester]

the failure pictured was sort of a fluke, as the car was body slammed right on the roof- Not the same as a rollover, but illustrates you can't forsee all possible crashes. That being said, the AutoPower pads could be much larger.
SCCA states
GCR - 93
9. Cars and Equipment
General
mounting plates not be less than .080 inches thick nor more than 0.25
inches thick. note too thick and you end up with a punch. The base becomes a die punch. Great for making louvers, not so good as spreading the load. The maximum area of each mounting plate in
the American Sedan, Improved Touring, Showroom Stock,
Spec Miata, and Touring classes shall be 144 square
inches. Plates may be on multiple planes but shall not be
greater than fifteen inches on any side.
b. The thickness of mounting plates bolted or riveted to the
structure of the car must not be less than the thickness of
the roll hoop or brace that they attach to the chassis, and
must be backed up with a plate of equal size and thickness
on the opposite side of the chassis panel. Mounting plates
shall not be more than 0.25 inches thick. The maximum
area of each mounting plate must be 144 square inches.
Plates may be on multiple planes but shall not be greater
than fifteen inches on any side.
c. Fasteners for bolted or riveted mounting plates must be
Grade 5 or better with a minimum diameter of 5/16”.

Not sure just bolting sheet metal is going to do much. If you can bend it with your hands... well.
Moving on.
Welding would be better than bolting, the vertical attachment is a great idea. That being said, I had larger pads welded to the AutoPower cage pads I had years ago. There's a picture of the results of 65-70 mph headon crash into a pole somewhere on here.
Even with larger, welded pads, the passenger side firewall bar punched through the floorboard. Of cours, the body was rippled all the way back to the c-pillar. Still Auto Power cage did it's job and I thank them.
I've seen AutoPower cages with 8 attachments handle a hard roof impact no problem. Again, you pays your money and takes your chances.

4 point, add extra plates in the floor board.

 

[mu22stang]

I will be doing some like this...

Taken from 20psirabbit's thread found here.

 

[David Hester]

that should work, but you REALLY want the beef INSIDE. The problem is punching through, not pulling through. "L" plate welded to rear seat riser or door sill works well.

 

[chrish900]

Thanks for the SCCA specs. The L-plates are what I was thinking about. I was also thinking of increasing the size of the feet on the rear bars as well. The following is from NASA's CCR. It is written for 6 & 8-point cages in their race classes, but the plate rules for bolt-ins apply to Time Trials as well.

Per NASA's CCR:
15.6.14 Mounting Plates
Each mounting plate shall be no greater than one hundred (100) square inches and no
greater than twelve (12) inches or less than two (2) inches on a side. Welded mounting
plates shall be at least 0.080-inch thick. Plates may extend onto vertical sections of the
structure. Any mounting plate may be multi-angled, but shall not exceed one hundred
(100) square inches total including vertical sections. Each mounting plate should have
an area of not less than nine (9) square inches.

15.6.14.A Mounting Plates – Bolt-In Cage
The attaching points of a bolt-in cage to the body must use reinforcing plates to
sandwich the body. At least three (3) bolts are required for each bolt-in plate and the
plate must be at least 3/16 inch thick. All hardware must be SAE Grade 5 or better with
5/16” diameter minimum. All nuts must be held securely by a locking system such as
safety wire, lock washer, Ny-lox, or jam-nuts.

 

[David Hester]

SCCA used to be 10x10, but changed to 12X12. Another thought would be see what the rules are in the group you want to compete with.
SCCA.ORG, has Time Trial 4 point bars rules, too. Bar thickness is more, also.

 

[brkntrxn]

Here are pics of an Autopower mounted in my old 99 coupe. This was originally a vert bar in our 01 vert. We modified the rear legs to put it into the hardtop and I never did like how the bar ended up too straight up and down. However, my installer wanted it done that way as it provided as much protection as possible (in his opinion).


EDIT: For those building a rollbar for a specific sanctioning body, please note that many organizations require the diagonal bar to connect above the driver's head and down to the passenger side. Mine was not build specific to a rule book and I warn the viewer not to copy it. See Sirl and David's posts below. -Kevin

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[chrish900]

NASA does not require roll bars/cages for TT. They do require bars for convertibles. For cars over 3500 lb. the tube dimensions are 2" x .120" DOM or ERW. TT rules do state that coupes with bars have to follow the rules in the rule book, i.e. plate size for feet, tube size, and construction standards. While not required, I just feel it is time to put a little money into safety.

 

[gcassidy]

Chris, what ever you decide on, I should do it as well. I'm having Billy look at mine after the holidays. I'll let you know what we come up with.

 

[chrish900]

Greg, based on what you currently have, I think MFE has the right approach (and pictures). I'm sure Billy has a good idea. Based upon feedback here and from others I hav spoken to, I would probably start with a 10" x 10" x 3/16" sheet, cut a notch in one corner 2"x3", fold up the 3" side to rest against the rear seat riser, fold up the 2" side to rest vertically against the side floor well, and weld it in place. I would also weld a re-enforcing plate to the contact area of the rear feet. You could bolt the bar right on the plate. Let me know what Billy says.

 

[David Hester]

:thumbsup:
Good idea.

 

[N/Angel]

what we did:

and all finished and painted:

 

[gcassidy]

Its so BLUE! :lol:

Good looking design, but a bit more than my wife would allow in "our" street car. Sigh.
I'll probably do a mix of the approaches above.

 

[chrish900]

Greg, my car is out at Piper Motorsport if you'd like to take a look midway through the process. I'm having them do a custom cage without door bars or the firewall and dash bars. They can be added later if I decide to go racing.

 

[gcassidy]

I might. I'm waiting to hear back from Billy whether he can do what I want.

 

[wheelhopper]

Did'nt Chris just get a welder? Lets do it ourselves Greg.

 

[Sirl]

Older thread, I know....

Sorry, but isn't your diagonal bar going the wrong way?? its supposed to make a halo over the driver?? yours is going from passenger side, down to the floor. Should be from Driver side, down to the passenger floor. I've never seen one go the way yours is... IMHO.

Here is a pic of mine. Autopower bolt in road race bar. No comment on the bolt in vs. weld in controversy. This works for me and i'm very happy with it. Just hope I never get to use it.

 

[David Hester]

Or it is a righthand drive car, but I think you are right.... no pun intended.

From NASA Club Competition Rules

15.6.7 Diagonal Brace
One (1) diagonal brace shall be used in the same plane as the main hoop. The
diagonal should be one continuous path; meaning that it must conform to Diagrams
15.6.7a or 15.6.7b. Note- If the installation method from Diagram 15.6.7b is used, the
builder should pay close attention to alignment. One end of the diagonal brace shall
attach to the corner, or horizontal part, of the main hoop above the driver’s head, within
twelve (12) inches of the driver’s-side corner. The other end of the diagonal brace shall
attach to the mounting plate (or to the main hoop as close to the mounting plate as
practically possible) diagonally opposed to the driver’s head (passenger floor).

Another consideration on fit, You want the main hoop out as far as possible (close to, if not actually touching, the doorsills remember the "L" mounting to the floor and sill? ). This main loop not only protects in a rollover, but is also all you have to protect in a side impact....Much more likely than getting on your head. If the main hoop attaches in a plane INSIDE the plane of your seat (Note the bulge needs to be wider than the seat) your arm/ ribs/head are going to take the hit before the bar....