Building a cage for a pickup (relation to cab mounts)

[SteveM]

Quick question, but maybe there's no quick answer:

When building a cage for a pickup truck (let's say an S10 for example), should the cage be welded only to the cab & bed, preferably near locations of cab & bed bolts?

Or... is it preferable and common to weld the cage directly to the frame as well as the cab & bed, which would preclude any future removal of the cab and/or bed from the frame?

Just a hypothetical question for now, but I'm doing a quarantine-time build in my head.

Thanks,

Steve.

[Dodge Brother]

Steve
We welded the cage directly to the frame (out riggers) in our Second Gen. S10. This way was chosen as it stiffens the chassis and then we didn't have to worry about design compliance.
The rule book seems to indicate that mounting the cage to the body is only permitted for unibody cars but does not specifically say this. Perhaps someone else can confirm that point.
Trevor

[SPARKY]

We are going to mound directly to the frame and make the cab still be removeable

[Rex Schimmer]

Steve,
I would not even consider welding to the body if the vehicle had a real frame. The whole process of welding a roll cage to a modern day uni-body chassis is very marginal. You can install a roll cage in one per the SCTA rule book and it will pass inspection per the rule book but it will not be safe! Welding 1/4 inch plate to .025 thick material is asking for nothing but trouble regardless of what the size is of the 1/4 plate. Even if you weld the cage to the frame the connections to the frame need to have  extra plating to ensure enough strength to with stand a major crash. It amazes me to see some of the cages that pass tech and people actually run. My son, Duke, is presently building the cage for a Competition Coupe that has a frame made from 2 x 4 x1/4 wall tubing. I have attached pic to show how it is done, he has quite a bit more done on it now but this is the start. Note that every tube will have a load path that connects it to the base chassis or a tube junction that has proper eccentricity.

Rex

[SteveM]

We are going to mound directly to the frame and make the cab still be removeable

I'd be very interested in seeing how you achieve both of those factors.  I haven't been able to visualize that yet.

Steve.

[SteveM]

Steve
We welded the cage directly to the frame (out riggers) in our Second Gen. S10. This way was chosen as it stiffens the chassis and then we didn't have to worry about design compliance.
The rule book seems to indicate that mounting the cage to the body is only permitted for unibody cars but does not specifically say this. Perhaps someone else can confirm that point.
Trevor

Thanks, Trevor.  Did you run the tubes through the bottom of the cab, and then weld to the outriggers?  This renders the cab and bed non-removable, correct?

Steve.

[SteveM]

Rex:

I agree that it's better to go to the frame, and your son's Comp Coupe looks like it has an excellent start.

I'm just trying to get my head around a preferred way for something like a truck to be used in a class that more closely follows production / gas coupe type rules.  I haven't gotten my mind around how to best have a cage go through the floor of a pickup cab and also tie the cage into the frame (without cutting the cab into a whole bunch of pieces in the process).

Thanks again,

Steve.

[Stan Back]

Al Simon built the cage in my old roadster.  The cage was bolted thru the body onto the 1/4-inch frame.  The cage is removable.  The body is removable.  Sounds to me like a good way to build a pickup.

[SPARKY]

we plan on lifting the cab off building the cage cutting the floor out as necessary building the new floor so that it is re-moveable so the cab can be removed in the future if needed  we are building a mod truck and it will have a set back which will have to have new firewall any way---oh we are also using an extended cab.

[johnneilson]

Some years ago, different life, SCCA road racing.
I remember seeing a video with a mustang that went over and landed on the roof.
The main 4 cage points tore thru the floor and you could see them sticking up about 4-5 inches out the bottom.
The driver was OK, but it took some work to cut him out.

I did quite a bit of modeling to see what the attachments should look like, the 1/4" plate was too rigid and just tore the sheet around it. What I found in the modeling was about .090 thick plate about 5" x 5" on top of another .090 plate 7" x 7" deformed and did not tear the sheet below. Somewhere I still have the FEA diagrams.

However, this is not the proper way to build a cage mounting. Welding the cage to a unibody can be done especially if the frame of which you speak is in the wrong place. Also, making sub mounting plates and mounts that bolt sandwich in are acceptable.

John

[will6er]

Would it be a possibility to attach a donor floor to the frame, build the cage, and then attach the body around the perimeter? This would only be necessary for a "production" class.

#6302 XO/GC

[Dodge Brother]

Steve
Correct, we welded the cage down tubes directly to the frame and outriggers. The bed and cab will not come off again, without some serious cutting. However it may be possible to position the attachment points for the cage (outriggers and frame rails) so that you could bolt the cage through the floor of the cab/bed to the frame and outriggers, allowing removal of the cab/bed. Jim Dunn of the SCTA board sent me pics of his cage when I was building mine and I believe this is the set up he used on his pickup. I'm not sure if Jim is on this board but I could share a pic showing this but would want Jim's OK first
Trevor

[SteveM]

Steve
Correct, we welded the cage down tubes directly to the frame and outriggers. The bed and cab will not come off again, without some serious cutting. However it may be possible to position the attachment points for the cage (outriggers and frame rails) so that you could bolt the cage through the floor of the cab/bed to the frame and outriggers, allowing removal of the cab/bed. Jim Dunn of the SCTA board sent me pics of his cage when I was building mine and I believe this is the set up he used on his pickup. I'm not sure if Jim is on this board but I could share a pic showing this but would want Jim's OK first
Trevor

Good call - making a "cab sandwich" would be possible with a strong enough design and a suitable number of suitably strong fasteners.  I'd definitely check with Jim Dunn before moving forward.

[bearingburner]

Don't even think of not welding the cage to a frame. The last thing you want to think about as you go over on you head is will the roll mounting welds hold.