I organize a drone enthusiasts group in Fort Collins, CO, and we have some members working on similar custom racing rigs. One member has his own CNC and is designing frames for around ~$200 cost of materials that can jet around at 60+mph. It's incredible to watch.
I've focused more on building a custom rig for getting great video of backcountry skiing, but there's a lot of overlap in the video/radio tech. If anyone has drone questions, feel free to send them my way.
Unfortunately I don't have a video of his frame - My goal is to get one at our next meetup. It's hard to capture because the thing is zipping around so fast!
My videos (trying to iterate on getting better cinematic quality) are at www.vimeo.com/bnzelener
I believe his frame is CNC'd steel. It's really malleable, so when he crashes he'll just bend the bent arm back into place. He uses SunnySky 2300kv motors, KissESCs, a MultiWii flight controller, and a 1300mAh 3-cell battery.
I've focused more on building a custom rig for getting great video of backcountry skiing, but there's a lot of overlap in the video/radio tech. If anyone has drone questions, feel free to send them my way.