Speedo Off

Okay, I solved the infamous Ferrari speedometer issue. It is easy to do and cost less than $100 in parts. There is a company I found on the web called 12oclock labs. They make a programmable speedometer calibration device that they designed for motorcycles. Through working with them over the past couple weeks we were able to come up with a system that will work with the Veglia speedometers in our Ferrari's. They built a special board that works with their standard unit.

I have no affiliation with these guys so and I'll pull this link if requested to do so but since this is such a common problem I thought it was worth posting http://www.12oclocklabs.com/. Call them to get the part number of the correct unit and the special board since it isn't shown on the web.

I'll post the installation pictures and procedure in a few minutes.

Here is what the device looks like:
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First thing to do is remove the instrument cluster. This is done by removing the two screws in the lower right and left hand corners of the instrument cluster. One of the screws is pictured here.
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Here is the wiring diagram for the special board that they came up with. You will need to connect this like it is shown in the diagram.
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On the Ferrari side you will only need to cut the Red/Black wire on the connector. The wiring on the connector has two wires, an open spot, and then 3 more wires. The Black/Red is the second wire in the group of two. In the picture below I have already spliced it and connected the Brown and gray wires as shown in the diagram.
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Make up the rest of the connections except for the +12 V and ground. To do these you have one of two choices. You can cut the White and Black wires on the Speedo connector and splice into them. The White wire is +12 V and the Black is ground. I didn't want to have two more cuts just in case this didn't work so I ran a wire from the fuse box (located behind the panel on the passenger side foot compartment) to the 7th fuse from the left on the top row. This is the instrument cluster fuse. I then tied the ground to a good ground spot behind the cluster. Sorry but I forgot the ground picture. I was getting excited and wanted to test it out.
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Next you need to program the unit. It is very simple and listed on the directions. There is a link to a YouTube video on their site that shows you how to do it. You will need to get a GPS or some other device to tell you the speedometer speed vs what your speedometer actually reads. There is a simple calculation to do this. Mine was ((72 actual speed)/ (80 speedo speed))*100)-100= -10%. Punch it in and presto your speedometer works correctly.

A few people mentioned that the speedometer being off helps in a ticket. If you are worried about that you can always reprogram the device and make it as far off as you need before court. Just an idea Feel free to PM me if you have any questions.

Hope this helps!!

 

Will do.

 

I just got some more information from 12 0clock Labs on the SpeedoDRD unit used to correct the speedometer read out. The part number for the Ferrari Buffer board which you will need alone with the SpeedoDRD is FBUF, and the cost will end up being $12.99 to get a pre-built buffer board, they can also provide anyone the schematics or a board layout as well if they need them.

Why the buffer is needed;
The reason the Ferrari 348 needs this buffer board is because it used a positive speed signal pulse with pull-down resistor, this is basically the inverse of how a typical speed sensor signals works (speed signals are typically negative pulse with pull-up resistor)

How it works:
The buffer board takes a positive pulse signal, buffers and converts it to a negative pulse signal for the SpeedoDRD input,
then it takes the negative pulse signal from the SpeedoDRD output, and converts it back to a positive pulse signal for the Ferrari speedometer.

I assume there are more Ferrari model's out that may be using the positive pulse signal as the 348 does.
If by chance there are any out there that use the standard negative pulse signal, you will not need the buffer board. I think most of us have the Veglia speedometer so I don't think this will be an issue.

How to tell if the car uses a positive pulse system;
A volt meter measurement from the speed signal input to the speedometer will let the users know what type of pulse polarity your system uses.
A positive pulse system will toggle from around 1v to 10v with the vehicle slowly moving and the gauge connected.
With the gauge disconnected measuring the signal line, it will appear to always be around 12v as the vehicle slowly moves

I hope this helps. Their contact info is:
Brooks
(937) 719-1518
www.12oclocklabs.com

 

A question came up about the wiring to the SpeedoDRD side of the picture I posted in #28 above. The device that this wires to is above the quarter in the image in post #26. It is just flying leads that you wire together. If you order one of these ask Brooks to make the board with the leads from this device already soldered into the FBUF. This will eliminate the possible connection problems in the future.

 

On my speedo there were 5 wires coming into it. I disconnected the plug on the back and put a meter on each wire and checked it to ground. You have to move the car some and you will see the voltage change from 1 to 9 volts as you move a little. On mine it was the second wire in Red/ Black. It is pretty easy to tell since this is the only wire that varies as you move the car. My driveway has a little hill and I just released the brake and coasted a little and stopped. You have to catch it just right to get it to change. If you have a problem you can call the guys where you get the SpeedoDRD and they can walk you through it or PM me and I'll give you my number and we can go through it.

 

Great job. I'm glad to see that it works on other models. It is really easy to install and the guys from 12 O'Clock labs are great to work with. I would recommend that anyone with a speedometer off give this a try. It only takes a couple hours and can save a lot of tickets. For <$100 you can beat it.

 

That wouldn't work because at 10 mph it is one mile off and at 100 it is 10 miles off. It varies over the range. The faster you go the more it is off.