I recently purchased 2 little voltmeters they look like the sort that would go in a control or instrument panel they are connected with just 2 wires which provide the operating supply ( they light up green and red) however the green one states it will work between 20and 500 volts and the red one between 60 and 480 volts. When they are both on the green one indicates normally around 241 volts the red one shows 235 volts why the discrepancy I know it's not much but makes you wonder if one of them is lying. Secondly I've noticed that the green one tracks voltage changes faster than the red one and that a few times the green one jumps down to 238 then up to 241 multiple times while the red one stays the same and I think can see a slight flicker in my filament lamps when this is happening incidentally both meters are connected to the same plug a 2 pin 5 amp one
There is a forum member who borrowed a highly accurate GPS speedometer designed to accurately determine the performance of a car on a track rather than for avoiding a speeding ticket on a road. So we may have someone with a detailed knowledge and experience of recording vehicle speeds with GPS amongst us.
Yes it was BOD! I bought a "performance box" to see if I could crack 0 to 60 in under 5.5 seconds but decided that to confirm it, it really needed more abuse of the manual drive train than I was prepared to pay for...........Really a legacy from my boy racer days when a friend with an MGB was adamant that it would do 110 mph which was about 7 mph more than Autocar and other magazines had managed! I found the road test and how many mph per 1000 rpm in top which showed the speedo error correlating his claims and he found that the tachometer was more accurate to determine speed. It would be poor of me to suggest a generous overeading of mph (and thus total mileage recorded) was intentional to make the car appear faster and do more mpg whilst getting the tachometer as accurate as possible to extract maximum performance! This all alters of course when the tyres wear down................... Talking of which, lorries limited to 56 mph? Not if as I saw when doing an EICR at a testing station where the haulier fits just legal tyres to the lorry prior to re-calibration and lean on the guy to err on the higher side of 56, ie 56.9 when calibrating. They can get 59 mph on new tyres............
Yet to compare my Sat Nav with the performance box (same brand as the track and car magazines use) but the spec assures me that it gives altitude and incorporates this in giving speed. Sampling rate is also greater at 10/second. Perhaps we can find a hill on the way to Elex Andy and compare?!
There is a forum member who borrowed a highly accurate GPS speedometer designed to accurately determine the performance of a car on a track rather than for avoiding a speeding ticket on a road. So we may have someone with a detailed knowledge and experience of recording vehicle speeds with GPS amongst us.
Yes it was BOD! I bought a "performance box" to see if I could crack 0 to 60 in under 5.5 seconds but decided that to confirm it, it really needed more abuse of the manual drive train than I was prepared to pay for...........Really a legacy from my boy racer days when a friend with an MGB was adamant that it would do 110 mph which was about 7 mph more than Autocar and other magazines had managed! I found the road test and how many mph per 1000 rpm in top which showed the speedo error correlating his claims and he found that the tachometer was more accurate to determine speed. It would be poor of me to suggest a generous overeading of mph (and thus total mileage recorded) was intentional to make the car appear faster and do more mpg whilst getting the tachometer as accurate as possible to extract maximum performance! This all alters of course when the tyres wear down................... Talking of which, lorries limited to 56 mph? Not if as I saw when doing an EICR at a testing station where the haulier fits just legal tyres to the lorry prior to re-calibration and lean on the guy to err on the higher side of 56, ie 56.9 when calibrating. They can get 59 mph on new tyres............
Yet to compare my Sat Nav with the performance box (same brand as the track and car magazines use) but the spec assures me that it gives altitude and incorporates this in giving speed. Sampling rate is also greater at 10/second. Perhaps we can find a hill on the way to Elex Andy and compare?!