joseph mitro

agreed, that's why i made my own in under an hour. I bought a box of 25 sheetmetal gussets from Mittler Bros, and used 2 of them. they just aren't good for anything but 90 degree bends


agree in concept, but I'd have to see some data to back up the notion of adding them to every joint. again, my cage builder put them all over my cage, and I personally would have preferred he used the taco-style gussets if anything at all. assuming the welds are good, the energy should be dissipated more appropriately by tying nodes together rather than by adding single-plane sheetmetal. disclaimer....I'm not an engineer, i just stayed in a Holiday INn Express last night

joseph mitro

disasterman - Are you building the cage with specific rules or racing organization in mind? EDIT - I just noticed you looked at NASA's rules...see below

I might suggest tying the A pillar cage tubes to the chassis A pillar for strength and rigidity, same with the B pillar. Also, a jack tube under the middle of the chassis, and tie in the front strut towers to the cage as well. should make the chassis quite rigid.

EDIT - what part of NASA are you building for? GTS allows the A and B pillars to be tied to the cage.

VERBOTN

I like the funnel idea, this weekend at Sebring I noticed on the 24-hr winner that they used a heim joint to attach the net bar then it just "hinges" up into the buckle-tab, very slick.

disasterman

I built it with the intention of PCA and NASA. PCA would allow a tie to the A and B pillars, NASA does not. I avoided the tie ins for that reason, we pushed out to the point we are touching the B pillar.

Greg Smith

I was referring to 'one off' sheet metal gussets...
What NASA class?

Circuit Motorsports

I'm not sure how I feel about the heim joint setup. The Mustang Challenge cars came with that setup and I couldn't help but think that in the event of some bent sheet metal on teh door it could keep the window net from getting fully out of the way and impede egress. It is a real slick setup though.

fatbillybob

I did this to mine made from a corner gusset because with helmet and hans and full containment seat I can't get the back end of the net in. So I came up with this.

Julian Allen

I love threads like this one!

RedlineMan

Hey;

I have a heim joint pivot on another car in my stable. Mine is pinned with a clip so that it is easily removed from the mount pin. It works. Given the choice between the two, I like the funnel. It is right out of your way (as Circuit Motorsports mentions), and it is freakin clever!

disasterman

The 951 went back to the builder for some fabrication details unrelated to the cage but we discussed the issues brought up on this thread with the intention of modifying anything that may not pass scrutineering.

1. Safety restraint guides too close together. After talking to the Hans people, they recommended that the guides stay where they are because they line up with the seat openings (Recaro Hans Pro).

2. The diagonal brace with a bend near driver. This was approved on a previous cage (NASA) to allow a driver over 6'.

I will post a some photos of the finished three weeks or so when I finish buttoning it up. I appreciate the input.

RedlineMan

Ha!

I don't buy either argument.

1) Experts make a lot of noise about the belt distance, and then H&D say it doesn't matter? I'd almost trust Schroth more than H&D, given the ever changing positions of the latter. Schroth is VERY specific on this point. By the way, your mount points are TOO FAR APART, not too close. You'd be better off with split shaft collars so you could adjust and balance between close enough for HANS use but far enough apart to not unduly bend the belts through the opennings.

2) Why have a rule and then make an exception to it that largely obviates the effectiveness of the tube in question? The argument that it is necessary because of driver height is BS. I'm 6'5" and I have a straight diagonal. Utterly sepcious argument. In general, you put things wherever they need to be to meet the letter of the rule. In your case, the NASCAR bars complicate this because the main hoop must be in the door opening, but given 12" of terminus leeway on the driver's side, they still could have made a straight diagonal.

Just advocating, devilishly.

DWalker

Agree with the above-

fatbillybob

I totally agree they could have easily done a straight diagonal bar terminating some distance from the corner and still properly fortified the rollover hoop. That angled bar basically does nothing in the car but add weight. I also do not like nascar bars not supported at the sill plate or not having a lower sill tube at or below the level of the sill. Those nascar bars are basically unsupported in free space.

J richard

Two things, the rules, and safety.

I can understand the reluctance to changing anything, but it's gonna suck when you have to argue the rules with a scrut on a race weekend because it doesn't meet the letter of the rules. All I can tell you is I have not been allowed any exception on the diagonal, unless I had a prior logbook issued, do they have something written from NASA about it? I'm not being sarcastic; if they do have something I'd love to see it. At the very least I would take some good pics, find out who does tech for the groups you run with and ask them how it would fly. You'll get the real answer you need, is he going to give you a logbook for the car? Better yet see if you can get them to go by the shop.

The second is safety, and thats just what you *** is worth to you and what level of confidence to you have in the equipment. You're spending some serious cash on the build and IMHO they owe you one that is right. I don't think it's a matter that your cage will completely fail, its a matter of degree, you're door bars are much more substantial than my X, but if they were tied to the sill as suggested you would have much better protection. Same for the diagonal, My Safety devices cage came with no main hoop diagonal at all, and it's FIA/PCA/SCCA approved(not NASA) but to make it right involved adding the straight diagonal.

I am suprised by the answer they gave you on the belt loops, all the info that came with my hans, my hans belts, and my hans seat were very specific about the loop placement, and the diagram clearly indicates the hoops =/< than the seat openings to reduce the potential of the belts pulling to the outside and off the device.

Anyway just my .02....

RedlineMan

EXACTLY, EXACTLY, EXACTLY...

...why I do not like them outside of NASCAR. There is a lot more behind these door bars in terms of the structure that they rest upon in a stock car chassis. It has always been my contention that they are UTTERLY TOTALLY misapplied in a uni-body based sports car. In other words, it's not the door bar assembly itself, but what it attaches to that governs the NASCAR bar's efficacy. If you look at it this way, you should see te exception.

Yooda Man, FBB!