Landracing Forum
Tech Information => Safety => Topic started by: LANDSPEEDRX8 on April 08, 2020, 12:27:28 AM
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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
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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....
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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!
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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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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?
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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
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He's going to run Alcohol ? Modified GT is Gas only.
(I looked all over and finally found this info in his "Newcomer" post.)
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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
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Hey, don't tell all those guys with records in /BGT they can't use their blower... you might start an argument :?
:cheers:
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Yep Stainless, I too was wondering where it said I can't run a blower in GT? :-)
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You're right Blowers are legal in BGT. Sorry for the over sight.
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And while nit picking the kind offer of help, the stock gas tank need not be used. Oh well. cromag :-)
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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:
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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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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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Hondata crash if you haven't seen it. https://www.youtube.com/watch?v=McJJeukIWSA
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I can only speak to what a late model caddy had to do they started out with something that looked very similar--- they had to tie the bottom of the legs front and rear legs together, run one between the two rear at the bottom legs run a floor bar from back lower cross bar, to the highest point front cross bar that ran from bottom of legs up over tunnel to the other front leg. Then ran tubes under the drivers seat between the lower preminiter bar and the floor bar---
bottom line in my opinion you will end up with something that looks very similar to the diagram in the rule book---
if the car completely blows up and apart the driver will still be inside the cage with their legs contained by the funny car straps and their arms with the arm straps--- their head contained by the seat side bars and HANS ymmv
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how about L Sicillio cage afterwards that is another cage inspiring photo
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Sparky,
I have attached some pics of the cage I did for Lloyd Siallaci several years ago. The car was a 914 Porsche, which is uni-body made from 1 mm (.039) sheet metal. I attached the cage to the chassis in as many places as I could. All of the main tubes attached to a 1/8 inch plate that was the required size and that plate was welded to another 1/8 plate that was at least 1 inch larger in each dimension than the base plate and it was welded to the car. This made the equivalent of the required 1/4 plate but spread the loads over a much larger area.I also chamfered the edge of the plate that I welded to the chassis to minimize the amount of heat required to make a good weld and not melt a hole in the 1 mm sheet metal. I also did some of the base plate to the chassis using silicon/bronze rod which provides a very wide but compliant weld bead and requires less heat than steel rod. I also made the cage go under the driver for protection from the bottom as that 1mm sheet does not do much.
Rex
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Nice Rex the bigest diffference was the Caddy had what amounted to an upper and lower halo but tied for and aff and around the driver very very similiar
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Just want to say this support from the LSR community is incredible. Thank you to all those who have shared your opinion, guidance and advice. Coming from a drag racing background the LSR responses and conduct are much different to say the least.
I think we?re on the right track now.
Thanks again.
#GODSPEED
#GODBLESSAMERICA