147 Speedo Callibration

[dipper]

I tried the Jaycar unit in my 75 a couple of years ago. But IT DID NOT WORK, because allegedly Alfa speedos are "different". The two speedo experts in Adelaide were no help at all, though I did solve my problems in the end by using a speedo from a 3 litre in my TS.
However a 147 is much more complex than a 75 in the electronics dept, and maybe the Jaycar unit will work, but I think you need expert help (if you can find it).

[colcol]

Have you considered sending the speedo to a specialist in Melbourne and seeing if it could be adjusted to read correctly, save you a big long drive, there are speedo 'experts' in Melbourne that couldn't fix my 33 speedo, but then i found one that could, Colin.

[lmcpaulm]

I remember ringing Alfa the first week I got my 156 because my GPS says my car is consistently going 10% less than the speedo.... (and still does). They were particularly unhelpful and slightly flippant but said that the 156 will have around a 5% variation from the true speed.... Plus not to rely on the GPS because that also has a 5% variation as it just marks your distance travelled between two points and averages it to calculate your speed and may not be a true reflection of what speed you are travelling at an exact moment, ie when there's a speed camera!

However I can't be sure about the credibility of his analysis...

[colcol]

The 156 speedo being 5% out and the GPS being 5% out, 5% + 5%= 10%, that could be the problem, because being 5% out could be acceptable manufacturing tolerances, my 156 JTS has standard tyres and my GPS both always show about the same speed, have you tried going to a freeway where they have those speed checking digital readouts "check speed here" setups, i know of 2 in Victoria about 40 kilo out of Melbourne along the Hume and one on the way to Ballarat, that are only working about 30% of the time, 'your taxes at work', Colin.

[colcol]

Apparently at Repco, they sell a GPS speedo that reflects the speed onto the windscreen, you put a sticker in front of your vision and it reflects it onto that, like a heads up display, i have never seen one, but have been told about them, Colin.