35 replies to this topic

[jackuig]

Hi everyone,
Anyone had any experience with these SMITHS Digital Speedos? Swapping my clubby over to centre speedo, and not sure if the standard centre speedos will work because the gearing is different. I've seen that you can adjust these digital speedos to the exact spec of your car, but as you can see from link below, they're very expensive!

http://www.digital-s...lack-2072-p.asp

Are they worth the money? Or does anyone know if a standard 130mph cooper S speedo will work even though the gearing is different?

Cheers :)

[Ethel]

What you need is comparable tpm (turns per mile). Often printed on the edge of the dial.

[Richie83]

I've been thinking about one of these too. Tempted to use the GPS sender.

[Arthy]

Im pretty sure most original smiths speedos work, regardless of year.

 

I have retro fitted a centre speedo on mine and the speedo reads around 5mph too fast. I would need to correct the speedo drive in the box to do this, but I'll live with it. 

 

If you're going from a 2/3 offset clock, you'll need a new speedo cable. Unless you use another means of tracking speed such as GPS like the modern Smiths ones. 

Edited by Arthy, 01 June 2016 - 04:38 PM.

[jackuig]

What you need is comparable tpm (turns per mile). Often printed on the edge of the dial.

Do you know if there is a way to calculate your TPM from your gearing ratio?

[jackuig]

I've been thinking about one of these too. Tempted to use the GPS sender.

Yeah same, I think if I were to get it then it's as well getting the GPS sender, easiest to fit, and just as accurate as the other options.

[Spider]

I haven't used that particular speedo from their range, but I do have one of the others.

 

I wouldn't go any other way these days. So reliable and once adjusted, accurate. Handy with the Trip Meter too.

 

They really come in to their own if you've changed tyre sizes, final drive ratio, or have odd gears in the speedo drive as they can be easily programmed at any time to suit what you have.

 

While the intial cost is high, certainly when considering any re-calibration costs, they quickly become inexpensive.

 

I see that an option is available to use a GPS Sensor, which makes set up a breeze (nothing to do other than apply power). I'd say this could be a blessing, but also could be a curse, especially at times it can't get a decent GPS signal (high rise buildings, cloudy days make them slow to respond, tunnels, car parks etc)

 

The set up I have (which I think is available in this style of speedo) uses a sensor that screws on to the gearbox in place of the cable.

Edited by Moke Spider, 01 June 2016 - 09:00 PM.

[jackuig]

I haven't used that particular speedo from their range, but I do have one of the others.
 
I wouldn't go any other way these days. So reliable and once adjusted, accurate. Handy with the Trip Meter too.
 
They really come in to their own if you've changed tyre sizes, final drive ratio, or have odd gears in the speedo drive as they can be easily programmed at any time to suit what you have.
 
While the intial cost is high, certainly when considering any re-calibration costs, they quickly become inexpensive.
 
I see that an option is available to use a GPS Sensor, which makes set up a breeze (nothing to do other than apply power). I'd say this could be a blessing, but also could be a curse, especially at times it can't get a decent GPS signal (high rise buildings, cloudy days make them slow to respond, tunnels, car parks etc)
 
The set up I have (which I think is available in this style of speedo) uses a sensor that screws on to the gearbox in place of the cable.

Thanks for the reply, sounds like its worth the money in the long run!
Which make of speedo is it you use?

[Spider]

 

I haven't used that particular speedo from their range, but I do have one of the others.
 
I wouldn't go any other way these days. So reliable and once adjusted, accurate. Handy with the Trip Meter too.
 
They really come in to their own if you've changed tyre sizes, final drive ratio, or have odd gears in the speedo drive as they can be easily programmed at any time to suit what you have.
 
While the intial cost is high, certainly when considering any re-calibration costs, they quickly become inexpensive.
 
I see that an option is available to use a GPS Sensor, which makes set up a breeze (nothing to do other than apply power). I'd say this could be a blessing, but also could be a curse, especially at times it can't get a decent GPS signal (high rise buildings, cloudy days make them slow to respond, tunnels, car parks etc)
 
The set up I have (which I think is available in this style of speedo) uses a sensor that screws on to the gearbox in place of the cable.

Thanks for the reply, sounds like its worth the money in the long run!
Which make of speedo is it you use?

 

 

It is a Smiths one, but not that type. It's a 'generic' 100 mm one

 

http://www.smiths-in...lspeedo-441.png

 

(hope that link works)

 

<EDIT:  This is the sensor I have

 

http://www.carbuilde...rter-black-plug

 

and the adaptor

 

http://www.carbuilde...or-adapter-mini

 

I also put a small O ring between the sensor and the adaptor as I felt it might give trouble in time without one.

 

This set up's been through hell and back, including some deep creek crossings, this set up hasn't missed a beat (touch wood!)>

Edited by Moke Spider, 01 June 2016 - 09:51 PM.

[jackuig]

I haven't used that particular speedo from their range, but I do have one of the others.
 
I wouldn't go any other way these days. So reliable and once adjusted, accurate. Handy with the Trip Meter too.
 
They really come in to their own if you've changed tyre sizes, final drive ratio, or have odd gears in the speedo drive as they can be easily programmed at any time to suit what you have.
 
While the intial cost is high, certainly when considering any re-calibration costs, they quickly become inexpensive.
 
I see that an option is available to use a GPS Sensor, which makes set up a breeze (nothing to do other than apply power). I'd say this could be a blessing, but also could be a curse, especially at times it can't get a decent GPS signal (high rise buildings, cloudy days make them slow to respond, tunnels, car parks etc)
 
The set up I have (which I think is available in this style of speedo) uses a sensor that screws on to the gearbox in place of the cable.

Thanks for the reply, sounds like its worth the money in the long run!
Which make of speedo is it you use?

 
It is a Smiths one, but not that type. It's a 'generic' 100 mm one
 
http://www.smiths-in...lspeedo-441.png
 
(hope that link works)
 
<EDIT:  This is the sensor I have
 
http://www.carbuilde...rter-black-plug
 
and the adaptor
 
http://www.carbuilde...or-adapter-mini
 
I also put a small O ring between the sensor and the adaptor as I felt it might give trouble in time without one.
 
This set up's been through hell and back, including some deep creek crossings, this set up hasn't missed a beat (touch wood!)>

That looks really nice! But just had a dashboard custom made for the car, and the fitment for the speedo is for the 130mm. How long does it take to set up the digital speedo with the spec of the car?

[Spider]

 

That looks really nice! But just had a dashboard custom made for the car, and the fitment for the speedo is for the 130mm. How long does it take to set up the digital speedo with the spec of the car?

 

 

Cheers !  I love it.

 

How long does it take to set up?   The first time you do it, about 2 - 5 minutes at the outside, that will get you in the 'ball park' (ie, within 2 - 3 mph), then to fine tune it, ideally, take it for a run over a known length of road and fine tune it from there, which will only take a few mins at most.

 

Programming is done with a single push button (the same one that's used for resetting the trip meter) there's instructions here;-

 

http://www.caigauge....042-460-435.pdf

 

Seriously, I'm a techno-dork. If I can do it, anyone can.

 

<EDIT: I'm pretty sure the 130 mm speedo fits up and is calibrated in the same way>

Edited by Moke Spider, 02 June 2016 - 01:16 AM.

[Ethel]

 

What you need is comparable tpm (turns per mile). Often printed on the edge of the dial.

Do you know if there is a way to calculate your TPM from your gearing ratio?

 

 

http://www.guess-wor.../Tech/ratio.htm

 

The TPM stated on the speedo is what the speedo expects from the gearbox to be accurate. It's the rolling circumference of your tyres X the final drive ratio X the speedo drive gear.

 

You could count the turns needed to move on the odometer if you're unsure about the speedo's TPM.

[jackuig]

That looks really nice! But just had a dashboard custom made for the car, and the fitment for the speedo is for the 130mm. How long does it take to set up the digital speedo with the spec of the car?

 
Cheers !  I love it.
 
How long does it take to set up?   The first time you do it, about 2 - 5 minutes at the outside, that will get you in the 'ball park' (ie, within 2 - 3 mph), then to fine tune it, ideally, take it for a run over a known length of road and fine tune it from there, which will only take a few mins at most.
 
Programming is done with a single push button (the same one that's used for resetting the trip meter) there's instructions here;-
 
http://www.caigauge....042-460-435.pdf
 
Seriously, I'm a techno-dork. If I can do it, anyone can.
 
<EDIT: I'm pretty sure the 130 mm speedo fits up and is calibrated in the same way>

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

[jackuig]

What you need is comparable tpm (turns per mile). Often printed on the edge of the dial.

Do you know if there is a way to calculate your TPM from your gearing ratio?

 
http://www.guess-wor.../Tech/ratio.htm
 
The TPM stated on the speedo is what the speedo expects from the gearbox to be accurate. It's the rolling circumference of your tyres X the final drive ratio X the speedo drive gear.
 
You could count the turns needed to move on the odometer if you're unsure about the speedo's TPM.

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?

[Spider]

 

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.