I'm not finding info on floor framing in nhra rulebook

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MOPARMAGA

MOPARMAGA

" The other hard member"
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I decided I am now going to remove factory floor pan. I will replace it with .032 aluminum.
So that part is easy, the part I'm semi-struggling with is information on what a legal floor frame consists of, what is allowed for tubing, diameter and thickness.
I have mostly completed my 12 cage and I was going to get an AMD floor pan and install it around my cage, 2 by 3 outriggers an 2 by 3 subframe connectors but that **** is very expensive to have shipped.
So that's where I stand now, any help will be greatly appreciated.
Thank you guys
 
Good question. I don't recall seeing anything spec'd in the "general regulations" for a floor frame specifically. I think this just falls under the common sense category. I do know that a few of the rules in the general regulations point to an "OEM floor." For instance, if the floor is not OEM (6 sqf allowable for transmission access panel I believe), a rocker bar of certain spec must be installed. I reached out to my NHRA rep who said penetration of my 2x3 subframe connectors and outriggers into the stock floorpan was fine. I was sure to save that email.

If you're resheeting in the whole floor, I'd think you should at least install rocker bars if you weren't already. Other than that, I'd probably tie the seat mounts into the frame somehow. Of course, you'll need a driveshaft loop as well.

Lastly, for me personally, I'd upsize the material for the floor pan a size or two. 0.032" is pretty thin. That's what I used for my rear firewall, and I'm not sure I'd be comfortable with that material supporting any appreciable weight. If you step on a piece not supported by a frame member, I'd be worried about it deforming, or worse. It may not, but I tend to overbuild stuff. Disclaimer - I'm no expert, so take anything I say with a grain of salt.
 
I found your answer real quick on a Google search as my rule book was in the house. I would suggest you do a search rather than do things twice. Not knowing your planned ET I Dont want to give you bad info.
 
mopowers said:
Good question. I don't recall seeing anything spec'd in the "general regulations" for a floor frame specifically. I think this just falls under the common sense category. I do know that a few of the rules in the general regulations point to an "OEM floor." For instance, if the floor is not OEM (6 sqf allowable for transmission access panel I believe), a rocker bar of certain spec must be installed. I reached out to my NHRA rep who said penetration of my 2x3 subframe connectors and outriggers into the stock floorpan was fine. I was sure to save that email.

If you're resheeting in the whole floor, I'd think you should at least install rocker bars if you weren't already. Other than that, I'd probably tie the seat mounts into the frame somehow. Of course, you'll need a driveshaft loop as well.

Lastly, for me personally, I'd upsize the material for the floor pan a size or two. 0.032" is pretty thin. That's what I used for my rear firewall, and I'm not sure I'd be comfortable with that material supporting any appreciable weight. If you step on a piece not supported by a frame member, I'd be worried about it deforming, or worse. It may not, but I tend to overbuild stuff. Disclaimer - I'm no expert, so take anything I say with a grain of salt.
Click to expand...
Thank you, the grains of salt are more appreciated than you know lol
 
pittsburghracer said:
I found your answer real quick on a Google search as my rule book was in the house. I would suggest you do a search rather than do things twice. Not knowing your planned ET I Dont want to give you bad info.
Click to expand...
What did you use for a search question?
I searched my *** off but probably didn't ask the right question.
 
Okay, I just got off of the phone with the chassis guy he said I'm already heading in the right direction. I just need to tie the frames together running drivers side to passenger side and I will also add in the driveline safety loops Per the rules I need a rocker sill bar to tie in the front of main hoop to the the forward roof down bars and the dash bar. I will also add a 1.5/8 or 2by2 between my outriggers and build a frame for my seat.
I like the weight difference between steel and aluminum but I do like the fact I can weld in the steel so I'll go that direction.024 thick is just over 1 pound per square foot.
 
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