Roll Cage Question

[mweeks]

This is for anyone with the knowledge.

 

Question: Is the reason a welded cage stiffens the chassis because its welded or because of the attachment points?

[Tim Comeau]

The more points you can attach the cage to the chassis, the less the chassis will flex. Bolt in cages do the same thing to a lesser extent.

[mweeks]

Thanks Tim,

 

So, If I had a bolt-in cage welded that would improve its ability to stiffen the car?

 

And the rules say plates cannot be more than 100sq in. Can material be added to the base plates so that they can be welded to the door/frame area thingy? (main hoop)

 

Sorry for being a pain, but I want get as much done as possible now so I have less down time during the season. And I don't really want to do things more than once.

 

Thanks

[Tim Comeau]

Yes, welding a bolt in cage will make it stiffer. But, remember the goal is a stronger cage for safety, not a performance advantage.........

I plan on adding base plates to my bolt in cage this year for 2 reasons. They will help prevent the current small base plates from punching through the floor in the event of a big hit on the roof, and they will raise the cage height within the cockpit, giving me more head room.

You're not being a pain in the butt. I wish more guys would ask first. Some drivers have had to UNDO things. Call me about the "thingie" on the main hoop.

619.994-0919

[944-Spec#94]

Bolt in cages compromise on two things.

 

Firstly they bolt in so most have limited places to attach. They may not be optimal from geometry standpoint. Floorpan is ideal to stiffen the chassis.

 

Note that the Safety devices cage is a bolt in/weld in. This means you weld the mounts to the frame rails and bolt the rest togther.

 

The other compromise the bolts. Solid welded construction is just solid.

 

Also most welding cages can be optimized for the car and driver. They also can provide more space inside the car since each one is custom fit to the car and the driver. Also bolt in cages typically have minumum of bars. A weld in can have 6 mounting points, but many many bars as the rules do not limit the number of bars. The rule specify the MINIMUM number of bars and the maximum attachment points. Of course more bars = more weight, but those extra bars are not always that much safer. I have seen many IT cages with lots of extra bars, but still 6 points. I'd be bunch of them are there, but don't do much.

 

I have welding cage. It has 6 points and is of a simple design. No extra triangulation of bars because I did not want to add the weight. I do have 6 feet place where I want them and have lots of space in side the car as the bars are placed so that they blend into the normal sightline of the chassis. Welds are also flawless. If I want to I can easily take it back to the builder and have him add in a bar here or there keep in the existing 6 points.