Roll cages

[Thor06]

Hey guys, so I have a couple questions about roll cages. My buddy and I are going to put one in his track bitch RX7 and we are just wondering how hardcore we need to get about it. I've been looking all over the damn internet for like 3 days and havent found shit, except one site that basically said we need one... not much help.

Anyway, we're thinking about getting it certified to 9.00 or 9.50 because we want to make it safe for faster than we will be going, and I dont think high 9's are that out of the question when we get the whole setup done. Its going to get a pretty decently built 350 with a pretty decent shot of nitrous plus we're stripping and gutting the already 2500 lb car. ~500 rwhp on the bottle and 2100lbs with the driver should be fun eh? I'll make a project thread later.

So anyway, anyone know what kind of a cage we're going to need? Think an 8 pt cage will do it?

[Blackcrow64]

a 4 point is good enough for 10.99 IIRC...

**EDIT**
I was right... Here is the rest of the details you need...

Originally Posted by NHRA.com

A roll bar is required in any convertible running 13.49 seconds or quicker in the quarter mile, and in other cars beginning at 11.49. The roll bar is accepted in vehicles running as quick as 10.00 second e.t., provided the stock firewall and floorboard is intact, other than for installation of wheel tubs. The rollbar must be constructed of minimum 1 ¾ inch o.d. x .118 inch wall mild steel tubing, or 1 ¾ x .083 chrome moly tubing.

If the floor and/or firewall has been modified, then a full roll cage is required beginning at a 10.99 e.t. A full roll cage is required in any vehicle running 9.99 seconds or quicker, and any vehicle running 135 mph or faster (regardless of e.t.). The roll cage must be constructed of minimum 1 5/8 o.d.x .118 mild steel tubing, or 1 5/8 x .083 chrome moly tubing.

The roll cage of any vehicle running 9.99 or quicker, or 135 mph or faster, must also be certified by NHRA every 3 years, and have a serialized sticker affixed prior to participation.

[Thor06]

But what defines a "full roll cage"? Will those pretty standard 8 point kits do it or will we need to do something more crazy?

[vanilla gorilla]

High 9's?...Wow, thats a big goal.

[Blackcrow64]

Originally Posted by Thor06

But what defines a "full roll cage"? Will those pretty standard 8 point kits do it or will we need to do something more crazy?

[SilvrEclipse]

Damn, I believe Brian is on top of things in this thread

[Blackcrow64]

Originally Posted by SilvrEclipse

Damn, I believe Brian is on top of things in this thread

I call it 20 hours of being awake and pure boredom. lol

[MazdaX]

You can buy the DIY kits but I don't know if those are acceptable..Then again you can do the dimensions and locate a metal shop and have them bend all the tubing and weld it in and save some money.

There is a guy here out at RMR running 10.5 in his Nova and he only has a half cage. You may also want to check with NHRA about motor/weight limitations.

[Thor06]

Yes, Brian FTW. That helped a TON.

I wouldnt say high 9's are the goal, getting it running is the goal. Anything after that is gravy . No, but seriously, we're going to be happy with whatever we get. Apparently there is videos of RX7's with "mildly built Chevy 350's" in them running like 9.7-9.9 on YouTube, streetfire, or whatever so we are just kinda going with what we think other people are doing. Besides, it would be a huge pain in the ass to build a car for 10.99 and then run a 10.7, know what I mean? We're just trying to give plenty of head room off of the best possible scenario.

Bent pipe is bent pipe yo, they wont know the different between that and custom bent shit. I do know of two of my dad's friends with pipe benders and one guy that is a professional frame builder for dirt track cars, but I dont want the ensuing drama. I think we're just going to snag one of those kits and yeah they suck for fitment, but we'll make 'er work.

Also, this wont be a strict bracket car. We might do it from time to time just for shits and giggles, but we're not going to build the car specifically for bracket racing. Mostly it will be a weekend cruiser and we'll probably just run it on test n tune days.

[Blackcrow64]

+1 for me.

So anywho... Yes, piping is piping . Whether it be steel or chromolly. It only has to pass inspection once every 3 years for NHRA certification. And if you really think about it, nothing is going to change about it unless you are in an accident with it and it structurally weakens it. It isn't hard to do your own rollcage, just time consuming and tedious work...

[cantgo2fast]

My advice would be that if ur worried about the NHRA rules look at NHRA requirements im sure they have an online rule book. Just remember measure twice cut once