Bongo Fury

Hi All,
I recently replaced my chipped original speedo with a GA5R version as wanted it to be able to show me both mph and kph. I have been driving round for a while now and have noticed the speeds on the gauge don't correlate with those on my sat nav. I have tried removing and repositioning the needle as discussed in other threads however this doesn't seem to solve the problem once at higher speeds. It seems therefore that the speedo is progressively more inaccurate the faster I am going. Does anyone know if there is some sort of adjustment I can make to fix this 'percentage' gain? For information I am running standard 15" tyres.

Any help would be greatly appreciated!

Truant wrote:Hi All,
I recently replaced my chipped original speedo with a GA5R version as wanted it to be able to show me both mph and kph. I have been driving round for a while now and have noticed the speeds on the gauge don't correlate with those on my sat nav. I have tried removing and repositioning the needle as discussed in other threads however this doesn't seem to solve the problem once at higher speeds. It seems therefore that the speedo is progressively more inaccurate the faster I am going. Does anyone know if there is some sort of adjustment I can make to fix this 'percentage' gain? For information I am running standard 15" tyres.

Any help would be greatly appreciated!

Eyup mate~i recently changed my speedo & it was 8/10 miles per hour fast according to my sat/nav~i repositioned mine & as luck would have it is almost spot on~i just took my needle off turned ignition on & replaced my needle the other side of the stop~ all through the speed range it's 1 or 2 miles per hour out (slow)but it can be trial and error sometimes.

You say you're running standard 15" tyres, what size are they? it could be the profile of the tyre is putting the speedo out one way or the other?

Thanks for the replies. I will check the tyre sizes when I get home. I had another thought about the problem: my old speedo was an original one with a MPH sticker at the bottom of it. I presume this means it was chipped however, in looking at it, I can't see the chip anywhere. Could it be possible for the chip to be placed somewhere else in the dash? If so the chip would still be attached and might be throwing the newer speedo out? Can anyone tell me where I should search for the chip?
Cheers!

Truant wrote:Thanks for the replies. I will check the tyre sizes when I get home. I had another thought about the problem: my old speedo was an original one with a MPH sticker at the bottom of it. I presume this means it was chipped however, in looking at it, I can't see the chip anywhere. Could it be possible for the chip to be placed somewhere else in the dash? If so the chip would still be attached and might be throwing the newer speedo out? Can anyone tell me where I should search for the chip?
Cheers!

'chipped speedos' is just a term, the speedos are not actually chipped, a box of electrickery is inserted into the pulse circuit that feeds the speedo. If your speedo went upto 180 with a mph sticker on it then it has a speed converter in the circuit that needs to be removed before a GA5R will read accurately and will explain your progressive error in speed.

What you are looking for is a box/package similar to this :

Normally its close to where the wires plug into the clocks but doesn't have to be.

This needs to be removed, it normally consists of a positive & negative feed and a speed in & speed out. the wire that was cut and connected to the speed in & out needs to be reconnected and the + & - feed needs to be cut and insulated properly

hope this helps

Hi csmcqueen,
Thanks heaps for your help. Foraged around for a bit behind the instrument panel and finally found the 'offending' item. Have removed it and will now re-calibrate the speedo tomorrow. Am hopeful that it will start reading properly as it currently appears as though I am doing warp speed 5 when in fact my sat nav faithfully tells me I am in fact only doing 43 miles per hour ...

Thanks again for the great advice

No problem, if i was you I would set it a couple of mph faster than your sat/nav as it gives you a little leeway with speed cameras, mine is set to 3mph over just in case