There seems to be a variety of cheapo instruments on ebay incl GPS speedo. All Chinese of course but at <150 for a 6 guage set.....

Example
https://www.ebay.co.uk/itm/394335292298?hash=item5bd0370b8a:g:Sq4AAOSwv6hjc2DG&amdata=enc%3AAQAIAAAA0KuwyBBjLw9RNSyj%2BckQcYwuJoS2ToN5E0Oz9eSAiyeS w8Nu%2BF%2FzDACIs3eEXLICmOo6iXcx85CWibu6k4yNguQXDZDspeOgHtkm9rivqsitrYX9%2Bnnw3Y63cWN379X7GGfxJyEtI1BMujnYJcX0VlTwYhyh%2FCUEyeQOYuk1U0ZPoJJLWYJiMerwfx SoteDLcZlXyOSjOuh6WqnUI3EJ0rV7SAof7c9%2FKvMI9JnCm6n7MaqvfiU1jJfaQlewbu1qrvWsrvTxCwBxfMz7m386nxk%3D%7Ctkp%3ABk9SR8CEnqWKYg

Or
https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=six+gauge+speedometer+set&_sacat=0&LH_TitleDesc=0&_od kw=gps+speedometer+set&_osacat=0&_sop=7

Has anyone tried any of these?

Regards
spegru

a gps based speedo will not pass IVA

"Note 1: The speedometer must be of a type suitable for M1 vehicle
use. This may be digital or a dial instrument. The types manufactured
for bicycles, racing only, those that rely on GPS or those that require
switching as a separate function to that of operating the vehicle or those
that have a separate power source from the vehicle or where they do
not operate as an automatic function when the vehicle is driven are not
permitted. Where the device is in question the presenter may provide
evidence as to the suitability of the device for road use from the
manufacturer of the device.
"

gremlin1234 has covered the non usability issue.

You can also get free smartphone apps that use the phone GPS to give you a speedo reading. Tried them before (for comparison against the OEM tintop guages). The speed is pretty accurate, but as per gremlin1234's post the phone device isn't powered by (or even connected to) the vehicle.

You'd be much better with an acewell digital dash...

quote:

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Originally posted by Mr Whippy
You'd be much better with an acewell digital dash...

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Now you have my attention.

There seems to be no details on the sender needed for the 1st link.

I note the point about IVA but my car is already registered......

Not keen on the Acewell Digital as I'm trying to go for a classic look.
Normally I'd be focussing on ETB but these are soo cheap and GPS avoids one problem - although it does appear to create another on the tacho side

quote:

---

Originally posted by spegru
I note the point about IVA but my car is already registered......

---

Following this, does anyone have any feedback on the reliability of a GPS speedo? I have a Smiths speedo from an MGB but the cable wiggles mean it stops working after 20 mins or so (the inner cable works its way out of the back of the speedo) so thinking of replacing with an eBay GPS speedo. Post-IVA too so no problems there, but I do want something that works properly. Does the GPS connection drop out at all or is it pretty consistent?

A speed sensor and Smiths electronic gauge would be the ideal but seems to be a £300 solution vs £50 for the GPS! If the GPS ones are OK I might consider a Frankenstein modification of the MGB gauge...

Ta

I bought a cheap chinese usb powered digital GPS speedo as a back up for the speedo in my MGB (equally as unreliable as yours).

Only downside is it can take a few minutes sometimes to get a signal, but once connected seems to stay that way. I should imagine the fitted GPS speedo would have similar issues.

Thanks. That sounds OK, the engine can warm up while the speedo connects!
I reckon I'm going to get one of the GPS ones and see if I can take the mechanical gubbins out of the original one and fit the GPS behind the face with the original pointer. Doesn't seem possible to get a 100mm GPS speedo anyway (brand new Smiths aside) so hopefully I end up with something usable!