Jack, like you, upon seeing the Speed Demon rear suspension mounting in the middle of that span, I was concerned. So, I went down and visited the shop and got a surprisingly thorough tour from Steve. Below are highlights of the tour for whomsoever is interested.
The suspension mount is now triangulated. There are fixed tubing runs from just in front of and behind the pivot lug on the span, and in the same vertical plane, but upward to the crosstubes over the ends of the spans. In addition, there are pinned (removable for rear end installation) struts from lugs on the bottom of the tube where the pivot lug is located, downward and forward and rearwards to mating lugs on the frame and a lug added just above the bottom forward 4-bar mount. While this now seems to be adequate and serviceable, some of it has the look of ad-hoc additions. A simpler and more streamlined design would be possible, but there it is. The sliding Y-frame on the bottom appears again, something I personally don’t like, but something carried over from before.
The L-frame rocker is, in fact, steel, and when asked why there were no gussets between the arms, Steve said they just haven’t been added yet. In between the spring/shock units is a mount for a ride height LVDT. The rocker shaft is 1” steel round retained by washers and bolts as seen in the photos, running on brass sleeve bearings.
That’s about it for the rear suspension. More generally:
They intend to run at Speedweek 2015! There’s a lot of work to do yet, there were 4 guys working on it, they know it will be tight, but that’s the goal. They only just got the body panels in a week or so ago, so there is a lot of skin finishing and mounting provisions to make up. The frame is about half welded up.
The shape and dimension of the new car is essentially the same as the old, with three notable variations. The canopy is the same shape but now had some internal reinforcements. The top-mounted engine air inlet scoop is gone, replaced by inlets on the side of the body just infront of the “hips” covering the rear tires. Exhaust outlets will now be more-or-less flush with the body top instead of sticking up from it. The belly pan, which earlier tilted up from a location some ways in front of the rear axle, now tilts at the axle line.
The belly pan is about 1/4” honeycomb material, real stiff, with a very slick finish on the bottom. Fastened with bolts through low-profile counter-bored fittings bonded into the honeycomb.
They have some really slick low profile push-button connectors for the body panels that need to be put on and off a lot--engine cover, rear wheel covers etc. The connectors grab onto ball-ended studs mounted to the frame.
The front suspension now has direct-reading load cells for lift/downforce measurements. They plan on running the car 1/2” lower than before.
Considerable effort has gone into streamlining engine change operations. Quick disconnects on front and back for fluids and electrics. Flexible plumbing (except for water) is now a new crimp-on type, light weight and to be insulated. As per “F1” practice, but I forgot the manufacturer name.
Built-in lift eyes on the engine plates. Engines are done, they will be taking three displacements. The zig-zag upper frame tube splices are not a commercial item, they had them EDM’d. Trailer has hoist and beam running out the side door to handle engine changes.
The transmission unit is “self-contained”. All the air-shifter crap is mounted on it with just a minimum air supply and control interface to the car.
The engine cooling water reservoir consists of two joined cylindrical tanks. Holy cow! Somebody learned about the detriments of flat-panelled pressure vessels. Reservoir is fitted with two large blow-off valves in case of head gasket failure.
I had intended, but forgot, to ask about aero testing--CP location etc since that was raised as an issue after that last run. Perhaps another day.
