Two more cage questions: A-pillar and stiffening
#16
Burning Brakes
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One common 'dodge' in cage fabrication -
If the rules limit the number of cage 'attachment' points, that generally means those points where the cage is bolted or welded to the rest of the tub. So...drop the bottom of the main hoop and the forward members thru holes in the floor, weld those elements together, then jack the whole cage up inside the car so it's physically wedged against the roof or pillar supports, then slide the floorplates over the holes and weld it all together. It's also fairly common to cut the roof of the chassis, install the cage and then weld the roof back on so it fits really tightly. It's physically jammed together, you gain some stiffness, but it's not considered an 'attachment point'. The rally guys do this all the time (Pro rally cars = real cages).
Beware of trying to make an argument that you've built a cage outside the rules for 'safety' reasons ("I think this way is safer, so even though the rules don't allow it, I should be able to do it..."). The whole 'safety' canard is guaranteed to put a cynical smile on any Scrutineer's face, and when you see that smile, you know that the word 'bull$hit" is running thru his head. That argument won't fly anywhere.
If the rules limit the number of cage 'attachment' points, that generally means those points where the cage is bolted or welded to the rest of the tub. So...drop the bottom of the main hoop and the forward members thru holes in the floor, weld those elements together, then jack the whole cage up inside the car so it's physically wedged against the roof or pillar supports, then slide the floorplates over the holes and weld it all together. It's also fairly common to cut the roof of the chassis, install the cage and then weld the roof back on so it fits really tightly. It's physically jammed together, you gain some stiffness, but it's not considered an 'attachment point'. The rally guys do this all the time (Pro rally cars = real cages).
Beware of trying to make an argument that you've built a cage outside the rules for 'safety' reasons ("I think this way is safer, so even though the rules don't allow it, I should be able to do it..."). The whole 'safety' canard is guaranteed to put a cynical smile on any Scrutineer's face, and when you see that smile, you know that the word 'bull$hit" is running thru his head. That argument won't fly anywhere.
#17
Addict
Rennlist Member
Rennlist Member
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Originally Posted by Geo
I'm going to disagree about tying in the suspension points to the cage. IMHO it's NOT a 10/10 sort of thing, but an absolute basic of cage building that should be built into any cage unless the rules somehow prohibit this. The cage is the backbone of any tin-top race car. The cage should not only provide safety, but should stiffen the chassis as well. There is no reason NOT to do this. The time to do this is when the cage is first built. Design it into the cage.
You can easily lay things out so that the tubes are easy to add if you cannot find out whether they are legal. I think this is a prudent course of action if you are in doubt.
And listen to Der Professor. As I mentioned somewhere, he "has a lot of t-shirts."
#18
Race Director
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Originally Posted by RedlineMan
If you do not know whether the rules will allow it, IT DOES NOT. Certainly, I can't imagine any stock class anywhere allowing it. That is why I gave the advice I did.
I just think if the rules allow it and you don't do it, you're making a big mistake. To me it's not extreme, but rather required if you're at all serious.
#20
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Professore,
Rally cars using your idea of the jammed cage for legal stiffness may only be used for one season. I hope my car will last for years. Do you think there is a chaffing problem with the cage against the car? How much metal is lost or weakend by this rubbing. I'm I paranoid? I just do not know the metalurgy. Also, car metal flexes. For those using factory glass can the extra pressure of the cage on the A-piller for example cracks glass from all the vibration and movement?
Rally cars using your idea of the jammed cage for legal stiffness may only be used for one season. I hope my car will last for years. Do you think there is a chaffing problem with the cage against the car? How much metal is lost or weakend by this rubbing. I'm I paranoid? I just do not know the metalurgy. Also, car metal flexes. For those using factory glass can the extra pressure of the cage on the A-piller for example cracks glass from all the vibration and movement?