Mark Ayling Posted December 9, 2002 Share Posted December 9, 2002 I wonder if anyone can explain something to me... Firstly, my Apexi rev/speed meter has never read above 97mph - I vaguely understand that this is something to do with the way its wired in relation to either the bit which removes the speed restriction or the kmh/mph conversion? Secondly, on occasions, I have noticed that when on the move the rev/speed meter has shown a much too low figure, ie 7mph when I'm doing 40mph or something. Seems to be alright at the moment though, so its obviously an intermittent thing - could this also be related to a dodgy conversion? Any info appreciated! Cheers, Mark. Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted December 9, 2002 Share Posted December 9, 2002 Firstly, my Apexi rev/speed meter has never read above 97mph 99.9% likely cause is it's fitted to the ECU speed input wire which has a speed delimiter attached (clamping at 97mph) Just move the wire to the other side of the speed delimiter or output from the odometer and it'll be fine. Secondly, on occasions, I have noticed that when on the move the rev/speed meter has shown a much too low figure, ie 7mph when I'm doing 40mph or something. Seems to be alright at the moment though, so its obviously an intermittent thing - could this also be related to a dodgy conversion? Odd? Intermittent things like this are unusual. Intermittent suggests wires broken etc which would be a working/non-working situation not a MPH O.K. then MPH-7mph ??? This is compared to the speedometer reading I guess, or do you have a GPS meter? Could be the converter (please don't say it's one of mine ) Some converters (not mine) just blindly remove pulses from the digital pulse train to get the 5/8ths conversion. i.e. out of every 8 pulses comming in they drop 3. i.e. 1,2,3,4,5,6,7,8 becomes 1,2,3,4,5, , , ,1,2,3,4 etc etc Now on average the speed in reduced by 5/8ths but in reality for a digital system counting pulses this appears to be a signal bursting on and off. This could be the error you are seeing. Just a guess. Regards Pete Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted December 9, 2002 Share Posted December 9, 2002 Originally posted by TRL Performance Odd? Intermittent things like this are unusual. Intermittent suggests wires broken etc which would be a working/non-working situation not a MPH O.K. then MPH-7mph ??? Shall we have a wager on whether it's a Scotchlok ?? Quote Link to comment Share on other sites More sharing options...
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