21 Mar 2008

The front push-rod design went smoothly thanks to the Mitchell software. The design freedom of pushrod suspension is great since it allows achieving all the goals: placement, accessibility, aesthetics, and the target spring rate.

Ordered double-adjustable QA1 shocks with 6″ travel, identical units being used at all four corners. Also ordered the uber-cool Tilton
pedal set, never mind the price. Next will be the rear suspension design, starting with carefully measuring the Miata rear upright.

A long-term background exercise has been the chassis side treatment – how to make it clean, elegant, simple, yet functional. I should mention that while the car started out as a “mid-engine Seven” visually, it has diverged somewhat over time. All the various parts require small changes to the initial body shape; the end result is that the finished product will have its own unique identity – good.

17 Mar 2008

A hanging pedal assembly isn’t going to fit – nuts. It shouldn’t have surprised me; the hoodline is pretty low, and some (most?) Locosts use bottom-pivot assemblies, so what did I expect? Guess I’ll just have to deal with the different feel. Tilton has a very nice floor-mount assembly that includes clutch, dual brake plus balance bar, and throttle pedal, but it’s expensive. While they can be built from scratch, pedals are kind of, um, super critical. I think I’ll pass on designing them for safety reasons and go store-bought. If builders want to make their own, the Gibbs book already shows how. Buying one saves time and lets me get on with the design, and there’ll be enough room that builders can decide which way they want to go.

This means I have a new Tilton pedal assembly for sale, part number 72-620. It’s a steel, two pedal, three cylinder assembly, with the master cylinders pointing toward the driver. It does NOT include balance bar or master cylinders. It sells new for $234 through Taylor Race Engineering, but I can’t expect full price so I’m asking $175 plus shipping. It’ll head to Ebay this weekend if no one grabs it.

Regarding the shocks, I’ve decided to go with QA1 double-adjustables, about $260-$290 each. Like much of the design, builders can choose whatever shocks they want as long as they’re the same length and use the same spring rate. Between the expense of the shocks, pedal assembly, and my brother having bought corner scales that I need to pay half of, I’ll have to pick and choose what to get first.

15 Mar 2008

The front suspension pickup points have been chosen, and next is working out the pushrod and shock setup. I’d like to make the shocks a feature, visible from outside, but it’ll be a challenge to miss the driver’s feet, steering shaft, pedals, master cylinders, radiator ducting, etc, etc. Checking brake master assembly clearence though, shows there won’t be any choice but to use a bottom-pivot assembly. There’s simply not enough vertical space for an overhung type, even with remote cylinders. One perk of a floor or firewall mount is that I don’t have to snake the steering shaft through the pedals, or avoid putting the shocks there.

At the Cars and Coffee event were two really cool cars. One was an original Cobra, not that big a deal around here, but this one had a polished aluminum body, just like chrome and very impressive. The other was what appeared to be an unrestored Toyota 2000GT. I never thought I’d get a chance to see one in person; they’re just beautiful cars, very elegant. It’s a shame they were never imported; they could have outsold Datsun’s Z car but I think they were too expensive. A real shame. Interestingly, it was parked next to a Ferrari Daytona, allegedly the inspiration for its styling.