35 replies to this topic

[Ethel]

 

Thanks for the link, very helpful :)
So is it possible to adjust the TPM of the speedo? Do you know if this is an easy thing to do/if its possible at all?

 

Not really, you'd need to replace bits of the Speedo. It's more likely you could swap the whole mechanism between cases is both are Smiths, I haven't tried this with your combination.

[jackuig]

Ah okay, doesn't take too long at all then. Was it easy enough fitting the gearbox adapter that screws in?

 
East, Cable off, Adapter on, O ring fitted, Sensor on. Then just route the cable away from anything hot of that spins.
 
I thought I had some photos, but can't seem to lay my hands on any right now.

If you manage to find some photos that would be very helpful and much appreciated :)

[jackuig]

Thanks for the link, very helpful :)
So is it possible to adjust the TPM of the speedo? Do you know if this is an easy thing to do/if its possible at all?

Not really, you'd need to replace bits of the Speedo. It's more likely you could swap the whole mechanism between cases is both are Smiths, I haven't tried this with your combination.

Thanks Ethel :) Sounds like I might just have to bite the bullet and go for the digital. Expensive initial cost but seems to be the easier option in the long run

[tiger99]

How does it use the GPS? If it is relying on GPS to measure speed all the time it is utterly illegal. Your speedo must work at all times, independent of systems external to the vehicle. If it is using GPS to check it's calibration, only when you tell it to, but using the drive from the transmission to actually measure the vehicle speed, that is very good, and fully legal. I would like one that did that on any modified car to save aggro.

[tiger99]

By the way, if you have seen the original sketches by Issigonis you may have seen that he intended the Mini to have a full, unobstructed parcel shelf with a small ribbon speedo under the top dash rail. Can be done much more easily with modern display devices. A rectangular Digidash may be cheaper than the Smiths speedo.

[Richie83]

How does it use the GPS? If it is relying on GPS to measure speed all the time it is utterly illegal. Your speedo must work at all times, independent of systems external to the vehicle. If it is using GPS to check it's calibration, only when you tell it to, but using the drive from the transmission to actually measure the vehicle speed, that is very good, and fully legal. I would like one that did that on any modified car to save aggro.

there is a feature in mini magazine this month about fitting this speedo. It clearly states the GPS module is road legal.

[jackuig]

How does it use the GPS? If it is relying on GPS to measure speed all the time it is utterly illegal. Your speedo must work at all times, independent of systems external to the vehicle. If it is using GPS to check it's calibration, only when you tell it to, but using the drive from the transmission to actually measure the vehicle speed, that is very good, and fully legal. I would like one that did that on any modified car to save aggro.

This is probably my biggest worry about the GPS sender. I live in a very remote area, and I would be worried that the GPS signal wouldn't be very good, and I would lose the connection regularly

[Richie83]

How does it use the GPS? If it is relying on GPS to measure speed all the time it is utterly illegal. Your speedo must work at all times, independent of systems external to the vehicle. If it is using GPS to check it's calibration, only when you tell it to, but using the drive from the transmission to actually measure the vehicle speed, that is very good, and fully legal. I would like one that did that on any modified car to save aggro.

This is probably my biggest worry about the GPS sender. I live in a very remote area, and I would be worried that the GPS signal wouldn't be very good, and I would lose the connection regularly

unless I'm being dim, wouldn't signal be better in a remote area? Being that they'll be an unobstructed view of the sky and all?

[dklawson]

I have no comments on legality.  There are GPS sending units available over here from vendors selling programmable speedometers.

 

The GPS sending units work by sending a certain number of pulses per distance traveled... just like the sender Spider used sends pulses per mile based on mechanically driven components.

[jackuig]

How does it use the GPS? If it is relying on GPS to measure speed all the time it is utterly illegal. Your speedo must work at all times, independent of systems external to the vehicle. If it is using GPS to check it's calibration, only when you tell it to, but using the drive from the transmission to actually measure the vehicle speed, that is very good, and fully legal. I would like one that did that on any modified car to save aggro.

This is probably my biggest worry about the GPS sender. I live in a very remote area, and I would be worried that the GPS signal wouldn't be very good, and I would lose the connection regularly

unless I'm being dim, wouldn't signal be better in a remote area? Being that they'll be an unobstructed view of the sky and all?

Yeah true, no tall buildings that could cause loss of signal. But even when using these handheld GPS's for hillwalking etc, signal on them can be dodgy, so thats where I got the thought.
I think the most reliable sender will be the gearbox adapter

[Richie83]

How does it use the GPS? If it is relying on GPS to measure speed all the time it is utterly illegal. Your speedo must work at all times, independent of systems external to the vehicle. If it is using GPS to check it's calibration, only when you tell it to, but using the drive from the transmission to actually measure the vehicle speed, that is very good, and fully legal. I would like one that did that on any modified car to save aggro.

This is probably my biggest worry about the GPS sender. I live in a very remote area, and I would be worried that the GPS signal wouldn't be very good, and I would lose the connection regularly

unless I'm being dim, wouldn't signal be better in a remote area? Being that they'll be an unobstructed view of the sky and all?

Yeah true, no tall buildings that could cause loss of signal. But even when using these handheld GPS's for hillwalking etc, signal on them can be dodgy, so thats where I got the thought.
I think the most reliable sender will be the gearbox adapter

you're def right

[Ethel]

You should be able to sort the mechanical one to acceptable accuracy if it came off a Mini and is going on one. Have you tried Guess works calculator?

 

With the tyre size, final drive ratio and speedo TPM you can play around to see what effect swapping speedo worms & pinions has.

[jackuig]

I think I'm going to give this digital speedo a go, and will use the GPS sender. I will report back with how it is! :)

[jackuig]

How the GPS sender is working:
The GPS uses a minimum of 3 satellites to track your position and receive signals from the GPS antenna box. It then calculates how long it takes to receive the signal and then works out how fast you are travelling. The GPS sender which is supplied is a 10Hz sender so the satellites receive a signal 10 times a second to stop any lag for the speed.

[tiger99]

The satellites don't receive anything, they merely transmit to your receiver.And, you need 4 satellites for position as it has to be calculated in 3 dimensions.

I don't know if they test the speedo in the MOT yet, while on the brake test rollers, but if they do a GPS speedo will be an instant fail, as even if it has a signal it will read zero.

The question about GPS speedos keeps coming up, and every time these is nonsensical speculation by those who do not know and have not checked that they are legal. They plainly are not, as some careful thought would show, without the nonsensical debate which always follows.

Your speedo has to work everywhere. End of story.

Edited by tiger99, 06 June 2016 - 06:18 PM.