Car is now at Winding Road Racing to be caged by Juliann Pokorny (ex Team MER, CJ Wilson Racing, Gilfus Racing Enterprises, etc.). She's done quite a few Miata cages over the years. We'll be doing a hybrid of ideas from MiataCage and the work she did with Gilfus. Most of this is driven by the need for unhelmeted transit safety on both sides of the car, streetable ingress-egress, while not compromising on-track safety for the helmeted/harnessed/HANS'd driver in a time-trial style environment. All that with an overriding goal of being light and keeping the stock dash skin and HVAC parts.
Main hoop will be floor-mounted on fabbed boxes just above the OE ones tying in the rockers, floor pan and rear vertical. Doing this, instead of cutting out the OE box and going to the floor, allows the main hoop to be more vertical and creates space behind the unhelmeted passenger. The actual bar top ends up in the same place as a MiataCage. The vertical sections will have tabs that through-bolt to the boxed sections where the inertia reels and soft-top typically mount.
Front down tubes will have kicks along the top to keep them flush to the hardtop and away from unhelmeted occupants. We'll also gusset them to the A-pillar with dimple-died panels...for strength and because it looks cool.
Windshield has been removed so as to move the eyebrow as far forward as possible and still get 360-degree welds. Eyebrow also gets a kick-out.
Debating long and hard about replacing the OE dash bar with a custom tube, we ended up deciding to use just the OE piece, cutting off the unnecessary bracketry for airbag and center console mounts...and putting plates on the ends to better attach it to the down tubes (matching through-bolted plates go on down tubes). This allows the dash to be unbolted and removed, while giving similar levels of strength to a custom straight bar welded to the down tubes. I'll post pics as we begin that part. Suffice it to say that it should give the best of both worlds. No cutting of the OE box section strength, yet light and bolt-in.
Overhead, we'll do a fore-aft H tube in the middle of the roof, instead of the usual MiataCage style Z diagonal. I prefer the diagonal for strength at the rollover-critical windshield top, but I'm really worried about proximity unhelmeted. I sit fairly upright in the seat and close to the controls. A diagonal overhead bar would be a massive target for my forehead.
At this point, door bars are going to be simple, old-school rockers only (we'll leave the OE in-door bars. That's what I have in the CRX. I might eventually add a low "Y" to the driver's side, but I'm going with this for now.
I did all the prep work...along with Mr Freeze.
Tar mats gone, interior stripped:
Test refit of the OE dash bar...we'll be cutting away a fair bit of bracketry. Its 16 lbs as it sits, while bare tube of the same length is about 6 lbs. The stock tube is very similar in OD and gauge to 1.5" OD x .095 wall.