Automotive – Porsche Speedometer Replacement

The 930 doing what it does best

S

urprisingly, having a low-miles, all-original 1984 Porsche 930 can be a real bummer. It’s a ridiculously fun car to drive, and even washing it can be a sensual experience. The problem is that I never get to work on it. Nothing goes wrong (which, actually, is great) and making “upgrades” to such an OEM car is criminal. However, as a habitual tinkerer, having such a fine example of German engineering in my driveway is a huge temptation. This is why I’ve decided to gut it and convert it into a competitive drift car – – joking.

Luckily I’ve been able to satisfy my DIY urges on my VW Super Beetle (and it needs it!). Having said that, I still jump at the opportunity to do work, even if very mundane work, on its more mature, but “übermensch" sibling, the 930. The latest thing I’ve done is replace the speedo (not to be confused with the like-named, tight-fitting, TMI swimwear).

You can find a lot of Porsche 911 Turbos on eBay with questionable odometers (if you plan to buy one, I highly recommend first investing in an AutoCheck account). However, in this case what I’ve done is actually replace the speedometer with the original factory speedometer – a restoration if you will.

When the car was new, it was imported into the United States as a “gray market” car since Porsche was not exporting the 930 model to the US from 1980-1986. As a “Euro” car, it was converted to American standards, which including de-metric-izing the speedo/odometer. The gentleman who did the import and conversion, the original owner who I bought from, was thoughtful enough to keep the original German equipment, and I thank him for that. I live in Canada and I benefit from the superior metric system, thus my motive to do the swap back.

The American miles odometer has about 20,000miles (about 32,200km). At the time of putting it back in, the original had only about 340km.

Backside

The replacement is easy with only a few considerations – primarily where to hookup each wire. The instrument pulls out without any tools (but a good amount of fingertip strength is required and maybe a push from the back). Once out, grab your toolbox camera and take a snapshot of the existing wire hookup. Compared to the metric instrument, the terminals in the same locations can be used.

Before and after

The internals of the instrument are clever enough to accommodate the differences in scale as well as different upper range of 300^km/_h (186mph) instead of 150mph (241^km/_h). And yes, its documented top speed is 278^km/_h (173mph) – fourth gear at 6750RPM...and remember, this is a stock production car in 1984! And no, I have never driven that fast.

Now don’t worry, I plan to keep the “miles” speedometer with the car as part of its history – and not pass the car off as a 400km car. That said, I am curious how my local Registry of Motor Vehicles will handle the swap – have I just done something illegal? I’ll follow up next year when I get my next Motor Vehicle Inspection.