Mini tub frame integrity

[My-SS]

I have a question. When mini tubing a 1st gen Camaro, I see that a section of the frame work is drasticly narrowed where you make room for the inner tub. Question is, what does this do to the integrity and strength of the rear frame work of the car. More so if you plan to drag race with slicks and /or road race where the torsion loads will be great on the frame. Will it stand the punishment without more reinforcment? Thanks for the help.

[rchaskin]

I wondered about this too.

If you tub and plan to road race, I would assume you would also run a 3 or 4 link.
At that point, the narrowed part of the frames only function is to hold up the rear sheet metal.

I don't really know....only my two cents....

[67 ls1 vert]

Just add a thick flat strap behind the frame to strengthen it. I've done that to a few already.

[Schwartz Performance]

If you plan on road racing often or drag racing with slicks and have a lot of power, any old car needs the frame strengthened.
Sure, you can still minitub and not strengthen it, and it's not going to break the car into two pieces. It's just not ideal.

Most 4 link kits have a crossmber up top which will help the case, or you could also throw one of our chassis under it and not have to worry about the strength of the unibody back there :)

-Dale

[Todd in Vancouver]

I'm right in the middle of doing this now on my '67 Camaro and yes you do need to do some frame reinforcement . The kits for mini-tubbing lay it out pretty good but once you jump in and start cutting it will become very obvious what you need to do. There is also lots of great info threads around on doing it so it's not as daunting as you may think.

I'll post some pics after I transfer them from my iPad.

[LukeSportsman]

Along with some standardized strengthening of the frame rail, when installing the minitubs, I seam welded them to add strength/rigidity. As mentioned above that many of these cars will eliminate the leaf springs, but also many will have the rear "trussed" with roll bar and down bars that extend behind the tubs. Triangulation is a great solution.

[k72nova]

I’m just starting my DSE minitub install on my 72 nova, my frame rails get cut up pretty narrow too. I fought with myself about it for a few months before pulling the trigger on these and what I reasoned is that this has already been done to a lot of cars and I have yet to hear of a failure; even with that said though I might still run a length of 1/8” steel on the other side of the rail where it is narrowed just to be safe. I’m going to wait on that till I see where the torque arm lines up to see if this will be necessary or not.

[makoshark]

I installed minitubs along with a Ridetech Airbar in my car at the same time. When I had the frame opened up, I fabbed up some 10 gauge and made an L shaped reinforcement bracket to slide inside the frame rails. I also welded nuts onto the brackets for the Airbar to bolt to rather than just having the Airbar bolted to the flimsy frame rails. I welded the bracket to the frame using a series of rosette welds.

[68zz502fi]

I installed minitubs along with a Ridetech Airbar in my car at the same time. When I had the frame opened up, I fabbed up some 10 gauge and made an L shaped reinforcement bracket to slide inside the frame rails. I also welded nuts onto the brackets for the Airbar to bolt to rather than just having the Airbar bolted to the flimsy frame rails. I welded the bracket to the frame using a series of rosette welds.

Any pics of this mod?

[makoshark]

This is the bracket that is now inside my frame rails. There is another vertical piece that had to be attached once the bracket was positioned inside the frame rail. I didn't get a picture of that.

[MrQuick]

nice,

[68zz502fi]

Thanks for posting pics.