Saturday, October 18, 2008

Snakey


The Spitfire speedo I bought from the Spitfire Graveyard looked mint on eBay (above) and for real, but I found when installing it that it didn't have a 'zeroing' cable - and the cable from the old 13/60 gauge didn't fit. And they're n/a on the Canley Classics and Rimmer Bros websites. Oh well, never mind. But I later realised that the odometer and trip meters don't work. Hmmph. When Lionel Otto Instruments rang to tell me the tacho was ready I asked about the speedo, and the chap said it would be an easy fix. "Is it calibrated?", he asked. Which is where this story starts.

The best way to test a speedo's accuracy is to drive at various speeds with a GPS on board, and compare the two. They agreed almost perfectly around town, and I could easily convince myself that any difference was due to a slightly trembling needle. But a smaller error would be proportionally larger at higher speed, so I headed out of town to open it up a bit. The local mechanics have a favourite back road to check their work. It's mostly straight, like most Australian roads, and only a bit bumpy. Alrighty then!

At 100km/h on the speedo, the GPS said 96km/h - as good as a modern car, and erring on the slow side just enough to avoid a ticket. But the road was straight, so the taps were opened wide. By the time we got to a slight right-hander the GPS and speedo both read nearly 130, at which we backed off and sat at about 110 for the last stretch of seal. Turning around, the old lump got a better run-up, and we hurtled back toward town at 140, at which the GPS and speedo still agreed almost perfectly. Anything working perfectly on the Herald is unheard of, it's a collection of bits that work 'pretty well for a 40-year-old car'. So the speedo is calibrated!

The handling, though, was another story. Since its wheels were aligned shortly before going into storage it's felt a bit funny, with very little self-centering action to the steering. At 100 it's fine, but at 140 it felt as though I was riding a snake. It was very light and scarcely felt in contact with the road. The back would deflect one way or the other over bumps, and it was hard not to over-correct the steering. It's very direct compared to the 4WDs I usually drive, and I felt that over-correction would cause a positive feedback where it started snaking down the road, swerving more and more violently. Sweaty hands on the wooden rim didn't help, either! Having checked the speedo, we returned to town at a speed more befitting our age.

I've fitted lower, stiffer front springs, Konis, a lowering block and urethane bushes, so the basics are right. It's had enough shiney bits thrown at it for a while, so once I can get some more shims (none in Oz) it'll go into the local mechanics (with me watching) to get the alignment reset to something resembling the factory settings, albeit with a lower ride height and increased negative camber. I have my fingers crossed that it'll cure the snaking.

In the meantime I'm going to NZ for a break next week, and the speedo will be fixed while I'm away. That way I won't be tempted to drive with an ugly hole in the dashboard. We'll even get the odometer reset!

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