rollcage fab questions (2)

[so cal racer]

I am looking for an answer on the rollcage mounting pads. i have an 86 iroc camaro that i am working on . i read in the rule book that on unitized bodys there has to be 1/4'' thick plates top and bottom (sandwiched) and bolted to floor pan and or sill plates. do all of the mounting plates have to be 1/4'' thick at all mounting points it seems that they will be very  hard to form to to the sill and floor configuration. the reason i am asking this question is this car has run in nhra comp and has 1/8'' thick mounting pads now on the current cage. And 1 last question can the cage and pads be welded to the car body instead of being bolted. thanks for your help     Keith   (so cal racer )

[CNC-Dude]

 I have seen on a few occasions where a race car from one sanctioned organization crosses over into another one like LSR. And most of the times the rules of the LSR organization have stricter guidelines for car construction than the racing org. the car came from. So I would say that it probably needs to be upgraded to the 1/4" plates. It would be hard to imagine someone buying an old Winston Cup car, and still not having to upgrade it in someway to conform to LSR requirements. I would contact one of the tech advisers for a final say so, but if its in the rulebook, its probably the way it will have to be.

[tedgram]

  I think welded 1/8 plates are OK.

I am looking for an answer on the rollcage mounting pads. i have an 86 iroc camaro that i am working on . i read in the rule book that on unitized bodys there has to be 1/4'' thick plates top and bottom (sandwiched) and bolted to floor pan and or sill plates. do all of the mounting plates have to be 1/4'' thick at all mounting points it seems that they will be very  hard to form to to the sill and floor configuration. the reason i am asking this question is this car has run in nhra comp and has 1/8'' thick mounting pads now on the current cage. And 1 last question can the cage and pads be welded to the car body instead of being bolted. thanks for your help     Keith   (so cal racer )

[Glen]

SoCal racer
If you are running under SCTA/BNI you better get their approval first. I have seen vehicles turned down for non complience to the rule book. The rules are written from experience and accidents and failures from the past.
Take it to a lakes meet for a pre inspection or have an inspector come to your shop.

[FoundSoul]

so cal racer-- what became the end of this?  I'm at the same point in my build and struggling with the same question.  It appears the section of the rulebook (3.B) is specifically addressing bolt in cages, but I don't see separate specs for weld in cages.  I'm trying to get my fabricator (who really does know his stuff, came highly recommended, etc.  Just hasn't built an SCTA car yet) to go with 1/4" pads, but his concern is that the unibody car we're welding this into has roughly .025" floors.  Welding 1/8" plate to this is doable, and the plates can be nicely formed to match the contours of the unibody.  Welding 1/4" plate to .025 material he says it not very safe because the amperage used to weld to the .025 is too low for good penetration on 1/4 plate but works fine on 1/8 if you pre-heat the 1/8 plate a little. 

We're trying to build the vehicle to be safer than required and not trying to skimp, but having trouble digesting the rulebook on this requirement and if it applies to weld in cages, and if not what the requirement is and where it is in the rulebook.  Seems like a question every car out there had to answer at some point.

What's everyone running on their cars that have been repeatedly passing tech for years?

[Steve Walters]

I had the same problem when I built my car, at that time the rules clearly stated 1/8" top and 1/8" bottom for a total of 1/4".  I both welded, and bolted the plates, and also tied them in undernieth with sub frame connectors.  I think that the wording in the rule book got changed round which made the plate thickness a fuzzy problem, I have been to all the rule meetings since 2007 and don't remember the rule beeing changed.  You could use 3/4" plate, but the strength would only be as good as the area around the 25 gage sheet metal.  I would check with Dan or Mike to get a good answer, when I'm inspecting I would let the 1/8" top and bottom pass, but there is a lot of new techs', that work off of the wording and not common sense.   

Steve