Speedos tachos and iva

[Paulvx]

Hi folks

Starting to think about instruments and IVA and wondering what everyone has used to get through IVA.
Has everyone gone for a speedo driven from front wheel either direct drive or with a hall conversion unit- if so how did you prove it was accurate. My othe thought was to think about a hall sensor and chopper wheel on the transaxle/driveshaft. Still have an issue with proving accuracy of an electronic Speedo though.

Also what kind of tacho are you using and where are you taking the tacho feed from?
I still haven’t decided on carbs or EFI - in which case the gauges can all be driven via the ECU

All the best
Paul

[Richardab1967]

I have 356 gauge being driven by front wheel. This will be a problem for iva as they only have driven rear wheel rollers at the test centres so can only confirm speedo accuracy if you have rear driven speedo. Therefore you have to have it calibrated externally before iva. The only way i believe is at a 4x4 rolling road as they work on all rollers.

I assume you get a confirmation to show the calibration to the vosa test guys. Bit of a pain though trailering the car to the nearest 4x4 rolling road

Unless anyone knows any better solution

[Robneal]

there are a number of companies that will certify the calibration of your speedo if you give them the details of the rolling wheel diameter. You need to send the Speedo away and they will calibrate it and send it back to you with a certificate. This is what I am planning to do.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[Paulvx]

Cheers folks - going for a rear driven speedo