03-08-2024, 10:43 AM
Concerning the speedo, first thing to check (as John suggests) is that you have the right speedo, showing correct turns-per-mile figure.
If so, then pause to consider whether your car is currently as standard - for example do you have the correct rear axle ratio, gearbox and wheel / tyre size fitted? -as these can all affect speedo reading. The tyres are the most likely variable, but it was always thus.
Modern car makers are restrained by legislation, a speedo must read between dead accurate and 15% fast (i.e. erring on the "safe" side). I don't suppose that rule existed when A7's were built. And it may have been tempting for car makers of the 30's to allow customers to think their cars were somewhat faster than they actually were...
If it still troubles you, it is possible to:
(a) swap for another speedo, on the offchance that it might read closer - bit of a gamble
(b) construct or purchase a tiny intermediate gearbox which corrects the reading (obviously you have to calculate the necessary step up/down). Not the tidiest solution.
© Send it off to a specialist like Speedograph Richfield, who can re-calibrate it for you, for a price - they will require some basic measured data (turns of the wheel when pushing the car a certain distance).
(d) Just ignore it like most of us do :0)
If so, then pause to consider whether your car is currently as standard - for example do you have the correct rear axle ratio, gearbox and wheel / tyre size fitted? -as these can all affect speedo reading. The tyres are the most likely variable, but it was always thus.
Modern car makers are restrained by legislation, a speedo must read between dead accurate and 15% fast (i.e. erring on the "safe" side). I don't suppose that rule existed when A7's were built. And it may have been tempting for car makers of the 30's to allow customers to think their cars were somewhat faster than they actually were...
If it still troubles you, it is possible to:
(a) swap for another speedo, on the offchance that it might read closer - bit of a gamble
(b) construct or purchase a tiny intermediate gearbox which corrects the reading (obviously you have to calculate the necessary step up/down). Not the tidiest solution.
© Send it off to a specialist like Speedograph Richfield, who can re-calibrate it for you, for a price - they will require some basic measured data (turns of the wheel when pushing the car a certain distance).
(d) Just ignore it like most of us do :0)