Hello All,

I want to set-up my electronic speedo for my IVA. I have pushed the car and measured one revolution of the propshaft (magnet on propshaft) this has given a basic set-up.

I was going to do the fine calibration on the road with my GPS.

I have insured the car and my IVA which is on Thursday.

Will I be legal to do a test run to check / calibrate the speedo?

The paper work for the IVA say I am alright to be on the road for traveling to the IVA test and to get work done on the car...

I don't want to get nicked at this late stage....

Thanks Paul

You can only drive on the road if you going to an IVA appointment or returning from one, and also to an MOT or VOSA check, and also I think to a garage for repairs from a failed MOT/IVA but that would probably have to be a booked appointment aswell, not too sure on that one.

If you couldnt prove you had one of these booked then you could get in a bit of trouble, usually points and a fine but could end up with your car seized in the worse case if the police decide that your insurance is invalid during to not being registered and not on your way to a booked appointment.

[Edited on 9/11/13 by chrism]

I did my final calibration on the way to the IVA!
Just fine tweaking while I was driving along comparing against GPS!

Thanks for that......

I wait for the day and do the calibration on the way to the test.



Paul

With electronic speedo's you can calculate the settings. Allow 5% under speed reporting and bingo no uncertainty for the IVA. All you need is an accurate ratio for your diff (easy to measure anyway) and the diameter of a wheel.

You can check your speedo setup at home quite easily. Find the gear ratios for your box, diff and the circumference of your tyre. You can then make a simple spreadsheet that will tell what the correct speed is in each gear for a particular engine rpm. Then put the car upon stands, run it up to a certain rpm in a certain gear and check against your calculated speed and the tolerance in the iva manual. If there is a difference then work it out as a percentage and then adjust the circumference to suit. I may have may spreadsheet somewhere if you want a copy. Used this process to set mine and went straight through iva.

watch out for tyres getting bigger dia at higher speeds
i set mine to over read by about 7% and when it got upto 70mph it was only just in spec!

your better of reading higher than your actual speed under reading is a fail

[Edited on 9/11/13 by baz-R]

What speedo are you using, if ETB type this may help

http://www.etbinstruments.com/ETB_Gauge_Wiring_PDF/ELEC%20SPEEDO%20CAL%20INSTRUCTIONS.pdf

This as well from ETB

http://www.etbinstruments.com/Digidash_Downloads.htm

In DigiDash 1 Analysis Software Version 1.2 (Latest) open zip file and download exe file to calculate the speedo calibration figures

[Edited on 9/11/13 by wicket]

During SVA, I left the securing bracket off the speedo so I could just pull it out and adjust the calibration while they had it on the rollers.