School me on full roll cage pricing

[Fabman]

My current 4 point bar is 1.75 .120. I think I'm going to cut it out completely and go to 1 5/8" for the full cage. Is chromoly legal? I know I've seen somewhere it wasn't legal for road racing.

1 5/8" is not legal for road racing in most classes I am aware of, at least not in these heavy cars.
Chromoly is legal in most classes I am aware of.

 

[PatientZero]

1 5/8" is not legal for road racing in most classes I am aware of, at least not in these heavy cars.
Chromoly is legal in most classes I am aware of.

I meant to say 1.5" rather than 1 5/8". After doing some digging into the rulebook it appears I would be fine for SCCA but not legal for NASA. I might just keep with the 1 3/4" just in case I decide to run NASA in the future.

SCCA


NASA

 

[Fabman]

I meant to say 1.5" rather than 1 5/8". After doing some digging into the rulebook it appears I would be fine for SCCA but not legal for NASA. I might just keep with the 1 3/4" just in case I decide to run NASA in the future.

SCCA
View attachment 58602

NASA
View attachment 58603

What's your car weigh?

 

[Fabman]

1.75 x .120 is 2.09 lb/ft
1.75 x .095 is 1.60
1.75 x .085 is 1.512
1.75 x .065 is 1.170

 

[Fabman]

1.5 x .120 is 1.77 lb/ft
1.5 x .095 is 1.42
1.5 x .085 is 1.28
1.5 x .065 is .997

 

[PatientZero]

What's your car weigh?

2950lb

 

[Fabman]

2950lb

You just made the cutoff for 3000 pounds.
Looks like 1.75/.095 wherever you go.
Most of us s197 cars are over that 3000# number.
I seem to remember chromoly being legal at 1.75/.085 but I may be mixing up racing organizations....oval track rules are very different and that's where I come from so that always sticks in my mind.

 

[Dave_W]

One of the things I never figured out with rules makers was that they frown on chromoly.

I believe it's because chromoly (4130) can have embrittlement at the weld area unless it's given a post-weld heat-treat annealing.The embrittlement means the weld can easily break in a crash, collapsing the cage. There's also some recommendations / requirements for pre-heating the weld area, and backpurging the tubes to avoid carbon precipitation. I think some sanctioning bodies just deemed it too tricky for the typical racecar builder/caveman - more suited to FAA-certified airframe constructors.

 

[blacksheep-1]

Funny thing is, most kart chassis are moly, and are MIG welded, I can't think of anything that would put more moments on a welded area than a kart chassis and they hold up fine. Some of the oval kart guys use moly on one side and mild steel on the other and misc combinations to get the flex they need. the whole chassis is basically one big torsion bar.

 

[Flyboygsxr]

$6000 for a 6 point FIA approved cage from Vorshlag this year with NASCAR door bars.

 

[bauern]

2950lb

NASA says "as raced". If the additional weight of the cage puts you over 3000 lbs., I think you'd need to meet the higher weight requirements.

 

[PaddyPrix]

(Ignore, some combination of the forum and my browser is not showing me the latest posts from like days ago so I end up responding with something that has already been well covered )

 

[Fabman]

Check your organization's CCR, and then check the class which may exclude or modify that slightly. Per NASA's CCR 15.6.18 -
3001 - 4000 lbs 1.750” x .120” Seamless Alloy (4130), Seamless mild steel (CDS Mechanical), DOM, or Docol R8 (only) No ERW allowed.

Then for say, Super Touring -
All rules in Section 15 of the NASA CCR shall apply, with the following exceptions that shall supersede those in the CCR: CCR 15.6—Roll cages may be built to provide an unlimited amount of chassis stiffening. Any number of cage mounting points above the minimum required can be used. Any number of additional tubes, including those penetrating the firewall are permitted. Additional tubes converting the vehicle into a tube-frame chassis vehicle are permitted in ST1, ST2, and ST3.

Yes, the devil is in the details as they say. The SCCA CCR reads a lot like the tax code and just as confusing.
I was 100% sure by reading the rules that my car needed a .120 cage but a phone call to the head tech inspector said .095 was good. I didn't believe him so I made him send me an email stating it....just in case it came up later.

 

[PaddyPrix]

Yes, the devil is in the details as they say. The SCCA CCR reads a lot like the tax code and just as confusing.
I was 100% sure by reading the rules that my car needed a .120 cage but a phone call to the head tech inspector said .095 was good. I didn't believe him so I made him send me an email stating it....just in case it came up later.

So true. My guys called one of the two guys who'd be later inspecting it so that when it came serious time, they wouldn't waste anybody's time or money something that they could just clear up before it even became a problem.

 

[Tonymustang302]

What about docol? I really like fathouse fabs cage

 

[Fabman]

What about docol? I really like fathouse fabs cage

Pix?

 

[Tonymustang302]

Pix?

FatHouse Fabrications

Our services range from performance parts and installation, to full engine builds, forced induction, custom fabrication, and dyno tuning. We also offer innovative products including: race oil catch cans, light-weight battery trays, turbo kits, bolt-in seat mounts, and roll cage kits all...

www.fathousefab.com

 

[Fabman]

FatHouse Fabrications

Our services range from performance parts and installation, to full engine builds, forced induction, custom fabrication, and dyno tuning. We also offer innovative products including: race oil catch cans, light-weight battery trays, turbo kits, bolt-in seat mounts, and roll cage kits all...

www.fathousefab.com

Is it this one?
Check your rules as they typically limit bend count to a maximum of 4 per tube.

 

[Tonymustang302]

Can people sit in those back seats?

 

[Fabman]

Can people sit in those back seats?

Its a drag race cage, they look at things very differently.