Author Topic: Pre-Fab Bolt-in Roll Cage welded in, Legal?  (Read 8477 times)

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LANDSPEEDRX8

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Pre-Fab Bolt-in Roll Cage welded in, Legal?
« on: April 08, 2020, 12:27:28 AM »
I sent the question below about a week ago to Lee Kennedy (lee.kennedy@avmetrics.net)
but I haven’t heard back.  No fault on his part, lots going on in the world right now. 
So I figured I post it here.

If any Tech Inspectors can answer the question below I would greatly appreciate it.  Or if anyone knows the contact info to other Tech Inspectors that I can email the question to I would greatly appreciate that as well.

Here goes.

The vehicle being built is a Mazda RX-8 and will compete in the Category D /BFMS Class.
Goal is 250MPH.

We’re looking into starting off with a pre-fab Bolt-in roll cage but intend to have all bolted joints fully welded as well as all mounts/plates on the cage itself welded to the vehicle upon installation.  The link to the exact cage is below.  It will be constructed of 1-5/8” OD x .120” wall thickness mild steel.  The mounting plates will be 1/4” thick.  In addition we’re going to have a separate driver containment kit welded in as well.  Link and photo below, red tubes. 

Question 1:  Is it legal to run a cage in D /BFMS (200+MPH) that was pre-fabricated as a bolt-in cage but is installed with all joints welded instead of bolted and all mounting plates also welded into place on the vehicle instead of bolted?

Full Bolt-In 6-Point Roll Cage:
https://www.agi-precision.com.au/product/f-mazda-rx-8-full-cage-6pt-bolt-in

Full driver containment kit (in red):
https://www.summitracing.com/parts/cee-3187

Thank you very much for your time!
Richie
« Last Edit: April 08, 2020, 12:36:06 AM by LANDSPEEDRX8 »

Offline Stainless1

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #1 on: April 08, 2020, 11:38:06 AM »
Does the 8 have a frame... or will you be sandwiching the floor to attach.  You might need some structure under the driver... don't know what the current reading on the rule is... sides, upper and lower, front and back....
For the price, you might be better off cutting the top off, building the cage and welding the top back on... any race car builders in your area?  You can put your body on a custom tube chassis... the 250 range may be outside the capabilities of your stock chassis.... Purpose built might be cheaper in the long run....
Stainless
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LANDSPEEDRX8

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #2 on: April 08, 2020, 10:01:10 PM »
Does the 8 have a frame... or will you be sandwiching the floor to attach.  You might need some structure under the driver... don't know what the current reading on the rule is... sides, upper and lower, front and back....
For the price, you might be better off cutting the top off, building the cage and welding the top back on... any race car builders in your area?  You can put your body on a custom tube chassis... the 250 range may be outside the capabilities of your stock chassis.... Purpose built might be cheaper in the long run....

The plan was to sandwich it and also add support underneath to match the structure exactly in Figure 1, page 35 of the SCTA rule book.  Image attached.
If rules allow we will gladly tube chassis as much of it as possible so long as we're still eligible to run in D /BFMS.
Chopping the roof is a great idea, again if rules allow.  We'll definitely explore that.
Thanks for the input!



Offline Stan Back

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #3 on: April 09, 2020, 01:21:51 PM »
Methinks he means cutting it off to get access to the cage you're building ? not chopping it (lowering it) like you would a custom car.
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Offline jacksoni

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #4 on: April 09, 2020, 02:07:46 PM »
Methinks he means cutting it off to get access to the cage you're building ? not chopping it (lowering it) like you would a custom car.
I agree with what Stan is saying but the OP is running /MS in which case chopping the top is legal- Rule 5.D.4, and a potential  aero advantage thereby. And building the cage a lot easier in the process as mentioned. Indeed streamlining of all sorts are allowed. See the Category and class rules. In addition, any frame may be used so make whatever you want. But a question: what is putting you in /MS in the first place rather than /GT? Running Fuel or something or is the body already not legal for /GT?
« Last Edit: April 09, 2020, 02:14:12 PM by jacksoni »
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Offline Stainless1

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #5 on: April 09, 2020, 04:13:32 PM »
Jack that is an excellent point... If he is leaving the body stock and can meet the other requirements for BGT or BMGT those could be better choices. 
And yes, I meant popping the top to make it easier to install a cage... but in MS the chop is legal. 
So somebody needs to study the book and decide what they really want to do... If full on race car with tube chassis and top chopped cowl back RX8 body then Modified Sports it is.
Stock body could meet GT and/or MGT
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Stan Back

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #6 on: April 09, 2020, 05:06:41 PM »
He's going to run Alcohol ? Modified GT is Gas only.

(I looked all over and finally found this info in his "Newcomer" post.)
« Last Edit: April 09, 2020, 05:11:21 PM by Stan Back »
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Offline RaceEngineer

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #7 on: April 09, 2020, 09:01:38 PM »
In Modified Sport-- For 2 seat sports cars--you can run fuel or gas, NA or Supercharged (blown).   Coupes can chop the top (windshield must have a 5" vertical height)  Wheel base maximum is 130", any frame, body can be channeled  . Any aero mods ahead of and including the cowl (front wheels may be enclosed).  Full belly pan and engine swaps any location is legal. drip rails may be removed.  windows may be flush with the body. Skirts, spoilers and strakes allowed. front track may be narrowed to 27".  This class is essentially Comp Coupe for 2 seat Sports cars including convertibles

In Modified GT--For 2 seat sports cars--stock body, stock wheel base.  one of the following mods required- full belly, QC rear end, engine swap or   FWD to RWD or RWD to FWD  Gas only but blower legal.  Air dams, splitters, spoiler (non roof mounted unless stock) are legal. This is essentially Gas Coupe for 2 seat Sports cars including convertibles

In GT Sport--For 2 seat Sports cars--Gas only, No blowers, stock body and wheel base.  (including stock gas tank which do need to be used)  Wheel openings may be radiused for clearance.  This is essentially Production for 2 seat Sports cars including  convertibles. 

Hope this helps   


In 
 

Offline Stainless1

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #8 on: April 09, 2020, 11:37:51 PM »
Hey, don't tell all those guys with records in /BGT they can't use their blower... you might start an argument  :?
 :cheers:





Stainless
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Offline Dynoroom

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #9 on: April 10, 2020, 01:25:34 PM »
Yep Stainless, I too was wondering where it said I can't run a blower in GT?   :-)
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Offline RaceEngineer

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #10 on: April 10, 2020, 01:54:26 PM »
You're right Blowers are legal in BGT.  Sorry for the over sight.

Offline jacksoni

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #11 on: April 10, 2020, 01:56:17 PM »
And while nit picking the kind offer of help, the stock gas tank need not be used. Oh well. cromag  :-)
« Last Edit: April 10, 2020, 01:59:35 PM by jacksoni »
Jack Iliff
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Offline Stainless1

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #12 on: April 11, 2020, 11:10:37 AM »
Yes, you don't have to use the stock gas tank but it has to be there.... When we ran GT we used the stock gas tank as a water tank...

So LSRX8 whatca gonna do with all these options....  cromag  :cheers:
Stainless
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Offline johnneilson

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #13 on: April 11, 2020, 11:25:40 AM »
Back to the cage question, I do not like the bolt in cages. This from a Father who raced his Son for years in SCCA and karting.

I did work with MazdaTrix in Signal Hill CA.

I know that Dave and guys have been doing quite a bit with the Rx8, you might want to give them a call and see what the cage options are.

There was another shop at ButtonWillow raceway Tom's Sevens only, they did cages etc.

FWIW, I pulled a few bolt in cages out of the SCCA cars and replaced with full cages, it is amazing what a couple inches clearance inside the car can do.

John
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Offline Rex Schimmer

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Re: Pre-Fab Bolt-in Roll Cage welded in, Legal?
« Reply #14 on: April 19, 2020, 01:43:18 PM »
If your target speed is really 250 mph then I suggest going to You Tube and look up the Hondata crash at El Mirage and ask yourself if a bolt in cage would have survived that crash? It is kinda like buying crash helmets, you can get some pretty nice "looking" ones for under a $100 but how much do you value your head? Same with roll cages, they need to be a safety capsule that enclosed the driver on all sides.
Rex
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