Roll Bar - Again

[drofdar]

I have my 55 Chevy in pieces and it is time to think about the roll bar/cage. With a mildly built 454, I am estimating mid to possibly low 11's. I had thought to attach the B bar to the mid body/frame mount by welding a larger plate to the frame and through bolt it. Then run the rear supports into the trunk and bolt through to structure welded across the frame in that area. Perhaps concurrent with shock mount kit. SW Racecars has a roll kit with 1 3/4, .134 material for $170. Or, they have a 1 5/8 cage kit for $250. Anyone know about this manufacturer? And any ideas or plans for the 55 Chevy bar/cage would be greatly appreciated. This will be a D/Gas car or possibly C/Gas.

[techinspector1]

I answered these questions so often that I finally wrote a paper on the subject. Please read and then ask your specific questions:

http://streetmachinesoftablerock.com....php?p=764#764

Here's some more stuff on re-locating the battery and wiring, etc. It is included in an interview I did with a former member on this board named Streets. It might help you to read the whole thing to get some input on the mindset of technical inspectors at the drag strip.....

http://www.streetmachinesoftablerock...opic.php?t=174

No matter whose tubing you buy, mic every piece before you ever fire up the welder. De-burr the ends and measure the thickness very carefully.

[Itoldyouso]

Tech: Tired of talking to the antelope yet?


Don

[techinspector1]

Not yet Don

[drofdar]

Tech, thanks for the quick response. I have both those papers listed in my bookmarks and have read them several times. Great info! I am hoping a member will know of a prebent kit that will adhere to the required specifications. That way I can tack it together, have the local pro weld it with gussets, and make you happy when you see me at the strip.

[Itoldyouso]

We bought the one for my Sons Capri from Summit. We have a tubing bender and notcher, but we did the math, and it was cheaper and easier to just order the prebent one than to bend and make our own.

We are going to add heavier floor plates than what they supplied, but otherwise it really looks great. Haven't got around to installing it yet, so the post tech did will come in handy when we do.Ours is a 10 point, but you can get others from them.


Don

[drofdar]

The Roll Bar Kit from SW Racecars has arrived. Since the 55 Chevy is a framed car, I'll have to weld or bolt the structure to it. I had thought to build up the oem frame outriggers 1.5 inches with box steel and weld plates to it. Then the inside plates (welded to the bars) would through bolt and sandwich the entire structure, body included, for a hard mount. I want to lift the body slightly off the frame anyway. But that brings up the question of torque flex and possible cracking of the body and the attachment points! And, I don't think a polyurethane type mount in the sandwich would pass tech. Any thoughts, ideas on this? Also, for Tech, your paper discusses the "B" Bar supports being attached in the trunk area. Since this is a framed car, would a 6x6 sandwich through trunk sheetmetal suffice, or would they need to be attached to the rear upper shock crossmember? And, again, thanks for your patience.

[techinspector1]

I think if I wanted the body up off the frame, I'd go ahead and shim the biscuits and get the body where I wanted it, then start on the bar/cage. I'd resist any ideas about including a flexible mount into the bar/cage structure. It will be ok to add structure to the frame to attach the bars to. I would just punch holes through the sheet metal floor of the body, build the bar/cage and then use large rubber grommets to form a seal between the bar and the body. The diagonal bars which support the B bar and run to the trunk area are usually run through the shelf panel speaker holes and will tie into the rear frame area as far to the rear of the car as you can get. It is perfectly ok to add some material to the frame in the rear area if you can't get the tubing in the place you want it. Add a crossmember between the rails to weld the rear diagonals to or whatever you have to do. Remember the rule, if the car is framed, the structure has to tie to the frame, not the trunk sheet metal.

[mooneye777]

i do not know about the kit you are lookin at, but I had a 225" super comp dragster built in 1997 by S&W. it was a fantastic car. they are a very good company to deal with, and they for sure know what they are doing. you will not have any problems with them,