Speedo Conversions

Winniebongo · Post by **Winniebongo** » Fri Sep 29, 2006 10:49 pm

Our Bongo hasn't been converted to MPH although it was supposed to be when we got it. What is the best way to do this, I believe there are chips but also mechanical converters and just dial faces which only change the spedo but not the odometre. I would like to know the pros and cons of this as it would be nice to have everything functioning as it should in MPH if possible.

samuel · Post by **samuel** » Fri Sep 29, 2006 11:27 pm

You can have it chipped, which is expensive (you might be rich!!) this will convert speedo and odometer. Alternatively a new face will mean you read in your speed in English but miles in French.

If you are poor like me you will need to carry out the latter. Firstly replace the dial with an English one (i.e. in mph). Then you get your missus on a pushbike with a borrowed mobile phone (remember we are poor!). She then rides ahead and you follow. When she gets to 30mph (she'll let you know via the phone whilst steering with one hand) you whip off the needle from the speedo face and replace it on the 30 mph mark. To ensure accuracy get her to pedal a little bit harder until she reaches 40 mph and recheck the speedo. Adjust as necesaary to within 1.5%. It may help to carry out the latter test on a slight incline, e.g. a hill.

By the way no animals such as hedgehogs or rabbits were hurt during this test and set-up and the wife is recovering quite nicely in the local hospital thank you.

Hope this helps. Kind regards to Marty for the loan of the mobile phone and to Cousin Johnny for the loan of the pushbike.

Wish you well.

Tim

grumpo · Post by **grumpo** » Sat Sep 30, 2006 4:33 am

The speedo is driven electronically with a square wave signal generated
from the gearbox. The converter chip reduces the frequency by the ratio
of Kilometers to miles. There are dozens of these converters (Chips) on
the market and most are unreliable and will break down eventually due
to inadequate spike protection. There are some good ones available but
you need to know the difference. Be aware that a failing converter can
cause other error signal problems which may not be immediately apparent.

Fitting the converter is a simple matter of cutting the 2 signal wires and
routing these through the converter and then adding a power supply to
drive the electronics. The power supply is best obtained from the radio
supply which becomes live with the ignition on. You also need to paint
out the speedo face "K" ie: Km/h = m/h.

Other than reliability, the only problem is you have a speedo which reads
0 - 180 Mph which is more difficult to read at exactly 30 Mph and many
owners are more comfortable with a speedo which reads 0 - 120 Mph and
is certainly more realistic.

Fitting a new faceplate involves removing the speedo needle, replacing
the faceplate and then refitting the needle. The problem is finding the
exact position when replacing the needle. If you replace the needle with
it resting against the stop it will be reading approximately 5 Mph too
fast because there is a small amount of tension when the needle is against
the stop. To calibrate it accurately requires some patience.

If you have, or can borrow a portable sat-nav then you can calibrate the
speedo to an accuracy of 0.1 Mph, or more realistically 1.0 Mph, at a
constant road speed of say 50 Mph.

Fitting a new faceplate will not change the odometer and they will both still
read in kilometers, however, most owners do not find this a problem and
even an advantage if you often drive in metric countries.

Personally, I much prefer a new MPH dial and would not fit a converter
"Chip" and I never venture "Abroad", however, the choice is yours.

Winniebongo · Post by **Winniebongo** » Mon Oct 02, 2006 8:04 pm

Thanks for the replies, very comprehensive. My leanings are towards the chip although I am not rich (wife seems to be better off than me?) and if it is going to be unreliable then that would certainly put me off.
Could I fit it myself and if so where would I get the info I need and the parts? Also How much are we talking about, Ball park figure and all that?
Cheers.

white van man · Post by **white van man** » Mon Oct 02, 2006 9:25 pm

the chip when breaking down and sometimes straight after fitting can cause the gearbox hold light to flash up a fault code remove the chip and problem gone might be quicker short term but long term seem to be more and more problems,get someone to fit a speedo face who can calibrate properly and never think about it again!!!

Keswick · Post by **Keswick** » Mon Oct 02, 2006 9:32 pm

We have a chip, so have a MPH reading and miles adding to the odometer. However, the miles were not clocked back so we have a kilomiles reading and thus a dilemma.

The dealer has given us the choice of any option we are happy with : taking out chip and fitting a face plate which he'll do for free, sticking with it as it is, or clocking back using a recommended service at whatever price that is. Briefly looking at the net that will be 120 pounds, and thats with a chip already fitted. So, overall, chipping is not a cheap option nor, by the sounds of it, particularly reliable.

Josh N Sarah · Post by **Josh N Sarah** » Mon Oct 02, 2006 10:16 pm

We had a chip fitted as well but like Keswick the odometer had not been clocked back.

Not being too happy with the whole kilomiles thing, we had the chip taken out and a faceplate fitted for ?60.00. According to Mrs JoshnSarah (who drives Bongo to work every day) it seems to drive a bit better since chip has been removed as well.

We just felt more comfortable with having the mileage recorded in the same format and didn't like the comedy 180 mph face

ChrisEm · Post by **ChrisEm** » Tue Oct 03, 2006 8:22 am

I bought a speedo face of evilbay for 5.99 which is actually good quality, I have straight stretch of unused road near me and used my sat nav and road angel to calibrate it. I then followed my partner at given speeds and it reads very well. There is a fact sheet on how to change it in the members section which is useful. It takes a little patience but I did the job in an hour or so with no problems.