i already know almost all of the roll cage rules for nhra, but me and the shop that is building my cage are scratching our heads against what ive randomly read on here lately. is it still permissible to weld the D bars to 6" plates near the center of the vehicle because i read somewhere you have to run a bar accross the bottom of the main hoop between the rocker sills and it goes over the center console hump and the d bars have to weld to that, and ive read no where in any NHRA rules about that. also, is mild steel still perfectly fine, im sure it is but just another one of those things. we are tig welding but i dont have the extra cash to jizz out for chromoly.

lastly, when doing the parachute bars to the rear, what size pin(s) or bolt(s) needs to be used when making it where the chute is a slide in or slide out to remove affair. not a permanent chute mount. THANKS!!!

 

Hey spoolinmat,
I would go to the horse’s mouth about the D-bars. E-mail NHRA tech official jmiller@nhra.com.
As far as CM or MS save your money and go for the CM. It is much lighter.
The pin size I have been using is 3/8 and I use.120 cm tubing instead of the .083 on my chute bars.
As far as who I am, I have built Jason hunts Civic and CRX and Brian Ballard's CRX and many other cars, and a few that run in the low 8's @178mph on drag radials. If you want your car done, check out my site in my signature. I have very reasonable prices. Good Luck

 

and he helped me out with some materials when i ran out at the last min!

thanks!

 

its kool, ill prolly still go with MS, im not worried about saving a couple of pounds at the expense of higher metal prices. My builder is a very competent builder and has been working with all different spec cages not just NHRA, we just never saw any real clarification on the whole d bar thing. it looks like the d bars can be welding to a 6" plate still as that saturn is on your website.

 

they say no, BUT the inspector that comes out of philly that cert'd mine said as long as the plates are welded over our subframe thats ok. we waited till he got there to do so. and from what everyone else says, he fails more cars in the north east than anyone else. this is how mine are done, and yes it did pass cert.

boxing the main hoop to the rocker plate helped alot too. he was impressed with that.



ill post up what my builder relayed to me from the inspector.

 

welded over the subframe, what area is it located specifically.

what does the boxing accomplish?

 

look under the car, see where the "frame rails" are? weld the plate over them.

and as far as boxing them to the rocker plate, it makes them sturdier by tieing them to the unibody in more than one place. my a pillars are the same way. https://honda-tech.com/zerothread?id=1576166

Rhodes does that to all their unibody cars.

 

so mild steel is ok, and i need a bar going accross for the d bars.

what about running a bar between the shock towers and mounting the rear bars to it, thats ok isnt it, ive seen a lot of that and i wanted to do that.

other than that i know all the other rules.

 

as far as i know, the "feet" all need to go to the frame (or in our case the floor.)

 

how can their be such a mix up on a damn rules that should be posted publicly. its not even clear on the damn website about how it should be.

 

i know. thats why we waited till the inspector got there and did it how he told us to.

 

the tunnel should be ok, but this is mine and my builders take on it. as was the inspector take on it. put the plates on top of the sub frames. which is what we did. and he certified it.


Modified by boostedcivicsir at 5:01 AM 5/16/2006

 

so damn confused now

 

this is the way the rule says it needs to be done


insane racer is teh one that did my cage came out very well

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vaporboy12 &raquo;</TD></TR><TR><TD CLASS="quote">this is the way the rule says it needs to be done


insane racer is teh one that did my cage came out very well</TD></TR></TABLE>

and when it comes time for me to recertify, thats how mine will be done.

 

pLZ show me these rules that i dont see anywhere in plain english. im prolly going to do it this way, but ive yet to see a rule justifying it. its not like it costs any more to do it that way, its actually easier to do haha.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vaporboy12 &raquo;</TD></TR><TR><TD CLASS="quote">this is the way the rule says it needs to be done


insane racer is teh one that did my cage came out very well</TD></TR></TABLE>

well is the main hoop not welded to a 6x6 plate? it looks like its welded to the cross bar that you say is legal, and you cert cages so which is it ?
it states page 86 4:11 roll cage, on unibody cars with stock floor and firewall, the roll cage may be bolted or welded to the floor/ rocker box via 6"x6"x.125" steel plates similar to the roll bar attachment requirements of paraghaph 4:10 page 74 which states, cars without frame use 6" square 1/8" steel plates on top and bottom of floor, securely bolted together with at least 4 3/8" bolts, or top plate welded to the rocker sill

 

What exactly is the rocker sill?

If I just weld my main hoop to the floor with the 6" plates, should I be ok? (6pt).

 

oh trust me there is a 6x6 plate

 

the rocker sill runs purpendicular to the floor. it is where my main hoop is boxed in at.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GHOSTWORKS &raquo;</TD></TR><TR><TD CLASS="quote">

well is the main hoop not welded to a 6x6 plate? it looks like its welded to the cross bar that you say is legal, and you cert cages so which is it ?
it states page 86 4:11 roll cage, on unibody cars with stock floor and firewall, the roll cage may be bolted or welded to the floor/ rocker box via 6"x6"x.125" steel plates similar to the roll bar attachment requirements of paraghaph 4:10 page 74 which states, cars without frame use 6" square 1/8" steel plates on top and bottom of floor, securely bolted together with at least 4 3/8" bolts, or top plate welded to the rocker sill

</TD></TR></TABLE>

yeah im a little confused, i figure you would install the cage as normal and weld the cross bar to the insdie of the cage and run the d bars to it, not wled the cross bar and then weld the main hoop to it? expletive!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SPOOLINmatt &raquo;</TD></TR><TR><TD CLASS="quote">pLZ show me these rules that i dont see anywhere in plain english. im prolly going to do it this way, but ive yet to see a rule justifying it. its not like it costs any more to do it that way, its actually easier to do haha. </TD></TR></TABLE>

Its not in the general regulations book but its in the SFI chassis book trust me this is for sure how it has to bee done here are a few i recently did and certified

 

My cage is welded to the 6'' plates that come in the kit just like boostedcivicsir did, the d bars or whatever youre calling them are welded to the hump in the middle of the car (where the exhaust runs) and it passed with no problems. I know many cars in my area with the same setup that have passed with no problems. I think the bar going across the floor is just personal preference for some.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beaver &raquo;</TD></TR><TR><TD CLASS="quote">My cage is welded to the 6'' plates that come in the kit just like boostedcivicsir did, the d bars or whatever youre calling them are welded to the hump in the middle of the car (where the exhaust runs) and it passed with no problems. I know many cars in my area with the same setup that have passed with no problems. I think the bar going across the floor is just personal preference for some.</TD></TR></TABLE>

actually it is a rule.
BUT it depends on your inspector.
as i was told by the guy that inspected mine, if it were a back halved car, it has to go the frame rails. on a car like a fox body or a camaro, there are no rails like ours running down the middle of the car. so there they need to be put on a bar between the b pillars. but if there are subframe connectors in said car, they have to go to them.

my inspector said he would do them the way i have them and passed it.

but in the chassis bible everyone refers to, they should actually go to a cross bar like six sigma has stated. i am good for atleast 2 more years so i will worry about it then.

 

where are these books, what a pain in the ***.