Anybody have any real life/educated guess numbers on how much a 6/8 point NHRA rollbar weighs in your typical GS?
Not really... Saftey is kind of important.... Chromemoly tubing is lighter than mild steel, and stronger, but will cost more... I guess you could find a catalog that sells roll bar/cage kits, and see if they mention the shipping weight, that’d be ballpark....
Probably not that much for 4130 CM.. maybe close to that with mild steel. 1 5/8 x .083 wall 4130 CM tubing is 1.4lbs per foot. typically takes 2 sticks (20-22 foot each) to build an 8 point cage.. so you might have 30 ft in it.. depends on what you do with the rear bars. Say you have 40 ft of tubing in it, which is doubtful for an 8 point cage.. the weight would be 56lbs. I am well versed with tubing at the moment, this is going on in the shop now.. Doing a 7.50 cert conversion on Mike Erickson's car, for the Billet head mill... it ran 8.50's with the 830HP 555 with TA heads, at over 1000 now, it's was going to be illegal.. And we are fixing a bunch of stuff this car needed updated and corrected, should be sweet when it's done here in a few weeks. JW
Just a note...………..CM is (for all practical purposes), the same weight as mild steel....it's just stronger, meaning you can use a thinner wall tube to have the same strength as MS. Hence the weight savings on CM vs MS.
Roll bar is" worth it's weight in gold" if you end up on the roof.... Surprised no one has used that yet....Jim
Typical mild steel cage is .118 x 1 3/4 mild steel.Chromoly is .083 x 1 5/8 usually equates to 1/3 less weight than mild steel. As Steve noted Moly is stronger.You can google the weight of a cage which may lead you to yellow bullet forum.There is a lot of old threads about this.Another note due to inconsistency of the cheaper mild steel,it is usually .134 wall which adds that much more
Just an FYI.......... While it's true that the NHRA minimum wall thickness is called out at .118" for MS and .083 for CM, 99% of cages are built with .134" EWS. I've built a lot of cages and this is standard. Taken from a chassis builders website; "Do not recommend .120" wall DOM tubing for drag racing applications since .120" wall is too close to .118" wall mild steel minimum spec." If a track official or inspector does a sonic test on your rollbar or cage, (and sometimes they do....I've seen it happen) they can deem your cage defective and NOT allow you to race. DOM tubing will have a manufacturing tolerance that allows the wall thickness to fall below the .118" dimension.
