The standard callibration of the speedo may include some 'flatter'! In the era, manufacturers routinely made their speeds read high.
Fugeo Speedo Needle.
- Thread starter Sunroof
- Start date
by 'flatter' you mean bullshit.
Exactly!by 'flatter' you mean bullshit.
Old Fuego speedo's are not very good they seem to have seized up during there long rest period. I now have three. Two sit on 100 kph with my battery drill the third that is the one from the car has no idea what it's job is now and did cause the original speedo cable to twist up and the new one broke despite it and the speedo turning cleanly with the drill. So I'll have to strip the other two as it is the odometer and trip meter that have seized. Causing grinding and crunching noises. I will get a handheld RPM meter and see what RPM the drill is doing as well as the speedo cable at 100 KPH.
It's quite amazing how much the circumference of a tyre varies during a drive.
For a vehicle to be Type Approved the speedo calibration accuracy had to usually be +10%/-0%, meaning that when the factory specified tyre profile was new, or had worn to minimum tread depth, or in some countries was slightly under inflated, the speedo had to by law never indicate a speed lower than it's actual speed but could show upto 10% higher. The odometer had different +/- specs that I can't recall off hand.
Apart from legal requirements and intrinsic difficulties with the apparatus, some manufacturers deliberately made their speedos read high so that customers would think that they had bought a Bugatti rather than a Model T!
Well the drill is doing 924 RPM and the speedo drive on the road at a GPS reading of 100 KPH is doing 903 RPM. So to calculate the % difference and set the needle accordingly. Then to fix the odometer at least on one of them.
I have finally managed to get one speedo close enough. 97 at 100 kph. I have done two things after a lot of experimenting to achieve this. On the others I did not get the trip meter working. Actually it is the easiest as it can be stripped down to individual wheels. The shaft was rusty and a good clean up fixed that. The oddometers were all worn where the axle fits into the nylon frame. That let the wheels rotate at random as the locking springs were not touching the stops. This is not able to be stripped practically as the end collets are embedded into the plastic gears. These wheels work by friction and so care in oiling the shaft is important. So I think the extra load of the trip meter kept the needle back to 100 instead of 120 kph. I also straightened the only remaining original needle and used that. Perhaps I'll try a new needle tomorrow. What a marathon effort it has been. I am now an expert until I need to do it all again and will have forgotten what I did by then.
Both my Fuego tacho and speedo have non original needles fitted by the last owner. This was perhaps done by an instrument shop as they work well and the speedo at least is spot on accurate comparing to a GPS. Odometer also working fine, although I did replace the speedo cable as there was some "flutter" in the needle.
The new cable came from Portugal? , but is maybe 200mm shorter and required me to re-route the cable to gain some length. Perhaps it was from a 1400cc version that perhaps only had a shorter 4 speed gearbox. I haven't bothered to go through the parts book to find out what options were available.
The tacho is probably correct, but doesn't seem to want to go to 6000rpm like the one I had 30 years ago did. I have an R21 2.2L that I bought very reasonably from Barry McAdie that will likely find it's way into the car, but probably with an EA Falcon Weber rather than injection.
The new cable came from Portugal? , but is maybe 200mm shorter and required me to re-route the cable to gain some length. Perhaps it was from a 1400cc version that perhaps only had a shorter 4 speed gearbox. I haven't bothered to go through the parts book to find out what options were available.
The tacho is probably correct, but doesn't seem to want to go to 6000rpm like the one I had 30 years ago did. I have an R21 2.2L that I bought very reasonably from Barry McAdie that will likely find it's way into the car, but probably with an EA Falcon Weber rather than injection.
I originally fitted needles off an R16 not sure about the tacho as I never really got around to checking it but the speedo one was ok but I had to slightly weight it with a small bit of blue tac, until the new cable sheared off. Left hand drive cables are 150mm shorter than RH drive ones all though the left hand drive one I fitted did reach.
