Continuing progress

Spent the past few weeks finishing up the jack points, drilling rivets out of the floor, detailing the horns, smoothing the underside of the “frunk” hood, collecting gauges and making arrangements for the transaxle modifications.


The jack points are painted…but I forgot I still need to weld on brackets for the horns.


These are just 8-inch bits of 1/8 flat bar. The horns (Wolos that look just like the original Bosch items) will also be affixed to custom-made aluminum horn insert pans as per the original. It’s hard to get a good picture of what the 550 horn pockets looked like, but I think I’ve got it down.

Getting these frame extensions fixed the the chassis took some drilling.


But once bolted through—even before welding—they tested out OK:


They look about right too. Not an exact copy of the originals, but pretty close.


Got a set of used 914 gauges to have converted into righteous-looking 550 gauges. Of course, that will also mean re-doing the binnacle because the right-sized gauges are different than the very nice 356-style re-pops that came with the car.


It would be so much easier just to install these and call it a day.


Converting the 914 gauges into proper-looking 550 models is apparently very time consuming and exacting. The 120 mph speedometer must be made into a 160 mph speedometer (or 250 kph, in my case—it’s a French car!). The 7,000 rpm tach has to be converted to 8,000, and screened to the proper font and redline. The combi gauge needs a proper oil temperature meter, with numbered dits. And all the trim rings have to be chrome. It’s a whole thing.

Palo Alto Speedometer specializes in this work. The quote from them: $2,200.

Holy Jesus!

I’m looking at other gauge shops now but the numbers drifting back so far are similar. Basically $1,400 and up. Apparently this is not an easy DIY job.

Luckily, my transaxle guy has been a bit more reasonable. I want (need, really) to change the 4th gear in this box from the .82 it came with to a .93, to shorten the step from 3rd to 4th. I also want a 3.44 ring and pinion, to make the highway cruise more like what the .82 4th would have delivered.

The transaxle was built by an Arizona shop in 2007 or 8 and never run. It got all the usual beef-up parts: hardened keys, super-diff, etc. The long 4th gear was the way, back then, to get a decent cruise rpm on the highway for engines that could pull it.

But the advent of the 3.44 gear obviates the need for such a compromise. The taller R&P means the cruise gear is fine with a .89 or even .93: 70 mph or so at 3,000 rpm. It also makes 1st gear usable, as it was originally designed to accommodate a 2000 lb car with four passengers and luggage trying to climb a long driveway with 50 horsepower.

Put it in a car weighing half as much with three times the torque and it’s just a waste.

For fun I looked up the original 550 gears and made a comparison to what this one will have, computing comparative sprints and top speeds given the torque and horsepower of the respective cars.


Gear ratios: (final)

Original Spyder                                      This car

1st: 3.18     (14.1/1)                                   3.80 (13.1/1)

2nd 1.94     (8.6/1)                                    2.06 (7.1/1)

3rd  1.23     (5.4/1)                                    1.26 (4.3/1)

4th  0.96     (4.25/1)                                  0.93 (3.2/1)

R&P: 4.43                                                   3.44


Top speed in

1st: 40 mph                                               34

2nd 66                                                        62

3rd 105                                                      101

4th 137 @7400                                         137 @6000

Imputed 0-60 (¼ mile)

5.8 (14.3)                                                    5.4 (13.9)

You can see how the original Spyder’s close-ratio gearbox rendered quarter-mile blasts beneath its dignity. I’m also heartened to see how nicely my car should stack up to an original: just a little faster, but not so insanely powerful that the ladder frame and beam suspension will feel inadequate. Basically, a perfect balance of quickness and fun (and quick enough to keep up with modern Z-cars and Mustangs with 3-4 times the horsepower, if that’s what turns your crank). Anyway, this week I’ll take out the trans and get it to my guy, who built the transmission in my Subaru-powered TD with the same gears, which work perfectly.

This weekend was mild so I broke out the fiberglass and stuff and fixed a hairline crack in the hood.


This was the usual fix: find the crack (it was hard to see under the primer), gouge it out with a blade, grind the area around it, sand behind it, four layers of cloth over it on the back, then kitty hair (UPol Fibral) in the front. Then sand that flat.


The hood will need some fine finish: a skim of regular filler and some blocking.

While I was at it I Fibralled the inside of the hood, to disappear all that mesh fiberglass pattern that would otherwise give away the game.


Once that coat was on and sanded with 80 grit, I moved onto USC All Metal,an aluminum-impregnated specialty filler.IMG_8982.JPG

This stuff is impossible to sand, but it looks something like raw, old aluminum. I’ll skim it with regular filler and prep for paint, but I may use the All Metal in other spots to bridge or substitute for aluminum panels where those are impractical.

Next on the agenda:

  1. remove transaxle
  2. weld tabs to frame extensions
  3. install horn pockets and horns
  4. set up gauge deal? How important is this authenticity?

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