Another RX7 in the mix
Posted by MeCalledEvan
Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
I finally got around to some cage pics. I snapped a couple but it was starting to rain so I was "motivated" to finish up quickly.
The cage is constructed to comply with the current RA rules but is not intended to be used for Rally at this time. "I, for one, welcome our Robot Overlords." - Philip J. Fry |
Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
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Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
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Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
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Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
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Evan Horner Ultra Moderator Location: Columbus OH Join Date: 01/03/2012 Age: Settling Down Posts: 109 Rally Car: 1983 Mazda RX7 GSL |
Thank you Phil! It's helpful to see the photos. I appreciate it.
I was looking at the X-bracing for the anti-intrusion door bars that you have. How is the elbow room with that design? It might just be because of the factory seats, but I've noticed that there doesn't seem like there's too much room for those bars to be very high up. How I sit in the car, I feel like I would hit my funny bone every time I turn left. Do you have issues with that? Update: I've started taking measurements of the interior of my Mazda. I'm using my CAD program to put together a point cloud and will start figuring out the geometry and design fairly soon. I'll post a screenshot of it once it looks less like a clusterfuck. I used to be very proficient at welding but haven't had much of a chance to practice the past few years because of working on a carbon fiber race car. I've been practicing welding a lot lately. I've decided to MIG the cage together because I'm still too much of a novice with TIG to trust myself. I've been focusing on welding different thickness sheets together, filling in holes, creating even beads on sheet metal, and welding at odd angles. All of which I think will be necessary to be good at with this. I'll be starting to practice on tubing soon. Any tips? Finally, here is a tangent that is hopefully a bit of a treat for everyone. I am the brakes design lead for my Formula SAE team, and have finally finished my design for the brakes system of the car. It is designed to be capable of decelerating the car at 1.38 G with 110 lb of pedal force. We are using Tilton-77 series master cylinders, an in-house manufactured bias bar designed after Tilton's bar, Wilwood PS-1 calipers with custom-made pads using their BP-10 pad compound (so that we can use cast iron rotors). The real glitches that I was facing during design was that in a normal car, the brake rotors are overbuilt by a magnitude of around 10 so that they can cope with the thermal energy they create during multiple braking cycles. In a Formula SAE car, there isn't this luxury because of the mass of the car, and the autocross style of racing. I created a thermal calculator that told me I needed to make my front rotors somewhere around 200 grams each to make them run in the ideal temperature range for almost any pad compound. This is impossible due to the strength of the material. At 200 grams, they would just turn into crumpled tin foil with the first braking cycle. So I really needed to make them as light as possible, while still retaining enough strength for a safety factor of around 2. Not only that, I needed to analyze and run their masses through my thermal energy calculator to get them as thermally balanced as I could. So after 2 months of hand calculations, guess and check, analyzing load paths, and learning and using assembly FEA (which, by the way, I'm now more proficient at FEA using CATIA than any of my professors), here are the rotors that I have come up with: Front is on top, rear on bottom. Front rotors are 0.96 lbs and 0.15" thick each, rear rotors are 0.449 lbs and 0.13" thick. "The more I learn, the more I realize I don't know and have so much more to learn." - Claude Rouelle, Optimum G lecture June, 2011 |
Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
Evan Horner Ultra Moderator Location: Columbus OH Join Date: 01/03/2012 Age: Settling Down Posts: 109 Rally Car: 1983 Mazda RX7 GSL |
Sean Medcroft Ultra Moderator Location: Edmonds, Washington Join Date: 02/12/2009 Age: Possibly Wise Posts: 1,802 Rally Car: Building a Merkur |
Alex Staidle Godlike Moderator Location: Δx = ħ/2Δp Join Date: 08/21/2009 Age: Settling Down Posts: 1,719 Rally Car: Various Heaps |
For Rally America only. NASA requires FIA. (something else Gene pointed out to me not too long ago). So yea, no reason you cant at least make an event though. I hear they run a rally or two in Oregon.  First Rally: 2010 First RallyX: 2004 (a bunch) Driver (0), Co-Driver (7) Organizer (3), Volunteer (3) Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5) Last Updated, Apr 9, 2023 |
Banned Mega Moderator Location: La la land Join Date: 01/25/2006 Age: Fossilized Posts: 3,740 Rally Car: Not a Volvo |
FIA is required for NRS logged cars, not RA cars at NRS events. RA can use properly mounted aluminum seats at NRS events. I knida always thought these were neat http://www.ultrashieldrace.com/prod.php?id=8 |
Albert Kun Junior Moderator Location: SF Ca. Join Date: 01/07/2008 Age: Possibly Wise Posts: 1,732 Rally Car: volvo 242 |
Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
Phil Meyers Mod Moderator Location: Portland, OR Join Date: 05/05/2011 Age: Possibly Wise Posts: 116 Rally Car: 1988 Mazda 323 GTX #214 |
This is my backup car for rally but I am planning on running it for ChumpCar and some track days. I did an RA legal cage in case the other car gets stuffed. Then I'll have a head start on the next rally car. "I, for one, welcome our Robot Overlords." - Philip J. Fry |
Banned Mega Moderator Location: La la land Join Date: 01/25/2006 Age: Fossilized Posts: 3,740 Rally Car: Not a Volvo |
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