Add tachometer to new V7 III Carbon Dark

[Mc Tes]

There are real differnces between SAE j1939 and SAE J1979. I tought somewhere in this toppic Speedhut said that there tacho were not compatible with the J1939.
It is just the poitn of the RPM infomation that is not 100% standard between all constructors who uses the j1939 protocol.
After 2010, all those who uses teh J1979 protocol have the same RPM info and coding.

I think it will not work, that Guzzi has his own system for RPM communication on the CAN bus. It is in there Tacho the info is decoded correctly.
If Guzzi would had used the J1979 Protocol there would have been no problem.

I am very interested in the results of your rechearches. Let ud know.

Mc Tes

[Kiwi_Roy]

I think it will not work, that Guzzi has his own system for RPM communication on the CAN bus. It is in there Tacho the info is decoded correctly.
If Guzzi would had used the J1979 Protocol there would have been no problem.
 
Mc Tes

I'm in complete agreement with you on this, Speedhut got right back to me and said it wouldn't work.
Getting one of Speedhut's pulse input tachometers to work is so easy, all you need is a wire from the ignition coil under the tank snd switched power, there will be enough to do configuring the gauge to match the look of the Guzzi speedo without worrying about
the bells and whistles of the different Canbus systems.

Did we ever rule out the option of purchasing the tach and loom from a wrecked bike? Do you think the tach information is available or would it require a different map for the ECU?

Roy

From page 2
Speedhut got straight back, their CAN-Bus tach is NOT COMPATIBLE but they did include a Standard alternative
Hello Roy,
Our J1979 is not compatible.  option from us would be our standard tachometer that compatible with all types of ignition (Single Coil, Coil Pack, Coil On
Plug, or Tach output from ECU/Aftermarket Ignition)
https://www.speedhut.com/gauges/Tachometers/Standard-Tachometer/?catid=f232|f9|f217

[Mc Tes]

@KIwi_Roy :

for their ECU Guzzi does just the same to provide the info to the ECU.
Once more, it is a pitty that Guzzi did not provide a doubled connector so for those who wishes to add a tacho of their own taste.

Make this relection : if MG would have wanted to be open to the world, they would in the past 10 years used the J1979 protocol! They did not!

If you can buy a second hand tacho from a crashed bike (not only the tacho but also the frame for the tacho and the speedo) it is just a matter of soldering 5 wires and a litlle bit of mounting work.
That can be a good option.

Mc Tes

                             

[pauldaytona]

There won't be much crashed v7III tacho's for sale as there are few sold. And one of the things that first destroy are the instruments.
If you use a normal tacho with pulse pickup, don't connect to the coil, but tap in one of the injectors. The grey/red or grey/black wire.  You can buy the connectors in male and female for that so can make a Y adapter without disturbing the original loom.

[twowheeladdict]

Reading through all these posts makes me even more OK with the adjustable shift light.  I set it to flash just above my comfortable cruising RPM, and go solid at the RPM I don't want to exceed before shifting.  The V7III really does let you know through the feel when it is in the zone.

[Bert Remington]

Mc Tes -- thank you for those pictures.  Yes I can see the two connector parts.

The BlueDash interface from the MG V7 III Stone schematic



Connector 51
------------

1 -- Ignition Switch via 15A Fuse B [Ar=Org]
2 -- Ground [B=Blu]
3 -- X4 CAN High Line (SAE J1939 with J1979 PIDs)
4 -- X3 CAN Low Line (SAE J1939 with J1979 PIDs)
5 -- Diagnostic Signal (K0Line ISO 9141-2) [Bi/B=Wht/Blu]
6 -- n/u
7 -- n/u
8 -- n/u

Pin 5 is the same signal as Pin 3 of Connector 40 which is the diagnostic connector the Lonelec plugs into for the GuzziDiag interface.



This raises the question: is the Lonelec converting the K-line signal to CANbus PIDs and sending them to GuzziDiag via the USB connector?  I'm thinking it is.  But I'm an optimist.  More research needed.

Returning to SpeedHut's CANbus tachometer, it just doesn't make sense for MG to use a unique J1979 engine speed PID for their CANbus tachometer and therefore SpeedHut's should work.

I haven't received my V7 III Stone yet but I kinda doubt I'll add a tachometer.  But if someone does want to put the CANbus SpeedHut tachometer on their V7 III, I will buy it from them if it doesn't work.  The MG tachometer has five wires: +12, Gnd, Can High, Can Low, and I don't know -- ??illumination. Make sure you get one without the shift light (ie, no pushbutton penetration) and is waterproofed (tell SpeedHut it is for a motorcycle).  So anyone up for this?

[Mc Tes]

MG does not stick to the SAE J1979 protocol but to the earlier SAE J1939 and in this protocol is uses it own coding for the tacho info. So the int J1939 protocol MG uses is not fully standard.
Keep this in mnd.

Mc Tes

[AZRider]

When the first v7 iiis arrived at Hamlin and I got all drooling over the Carbon Dark, I immediately looked at the connectors on the back of the dashboards and was disappointed to see that they are not the same as the one on the dual-gauge  models.
I'm glad you guys solved the problem and documented it here for the community.

An important note for anyone considering the simpler option to use a tach that just takes a pulse directly from an ignition coil: You need a tach that can work with 1/2 spark per revolution, not the common 1 spark per.

Why?  Guzzi does NOT use a "wasted spark" ignition, meaning that it only Sparks on the ignition revolution of the four strokes of suck-squeeze-bang-blow. Harleys started way back in the early 1900s with a wasted spark near TDC between blow and suck because it was simpler to spark every revolution and it didn't hurt anything, and they never changed. SO, most aftermarket tachs are made for the Harleys, and they expect one pulse per RPM. Even most "adjustable" tachs that say they can be set for 2,4,6, or 8 cylinder engines presume that the 2 cylinder setting is a Harley and can only go as low as 1 pulse per RPM. Our Guzzis, only sparking every other revolution, will read half of true RPM on those.

[Bert Remington]

As some of you may have observed, I've been doing a deep dive into MG's implementation of CANbus for MIU G3s and found an number of strengths and weaknesses, both of which I'm addressing and both of which solutions I will share because many V7 III riders are riding with their MI lights on and that's not proper operation.  And let's leave it there before I rant.

Back to the tachometer topic.  There were some who thought I couldn't make the excellent Speedhut CANbus tachometer work with a V7 III.  I'm calling you out.  My offer (to just the first US-only* member who accepts) is for you configure the Speedhut Freedom CAN-BUS tachometer to your preferences; send me those preferences (which I will confirm with you); I will purchase that tachometer configuration; I will assemble a connector (8-pin Bluedash) with CANBus-safe cable to the tachometer; I will post a picture of the tachometer working on my V7 III Stone; I will send you the tachometer with cable and connector; and you will repay me Speedhut's tachometer cost plus up to 30% for parts and shipping (I'll provide an invoice).  If the tachometer doesn't work for you, you pay nothing except return shipping, no questions asked.

If I can't post a picture of the tachometer working, you pay nothing and I eat crow.

GTM provides dual gauge mounting at https://gtmotocycles.com/collections/all-products/products/gt-motocycles-v7-iii-speedo-drop-bracket

* the US-only exception is Kiwi_Roy.  Even if he isn't the first to accept the offer I'll build one for him.

[twowheeladdict]

As some of you may have observed, I've been doing a deep dive into MG's implementation of CANbus for MIU G3s and found an number of strengths and weaknesses, both of which I'm addressing and both of which solutions I will share because many V7 III riders are riding with their MI lights on and that's not proper operation.  And let's leave it there before I rant.

Back to the tachometer topic.  There were some who thought I couldn't make the excellent Speedhut CANbus tachometer work with a V7 III.  I'm calling you out.  My offer (to just the first US-only* member who accepts) is for you configure the Speedhut Freedom CAN-BUS tachometer to your preferences; send me those preferences (which I will confirm with you); I will purchase that tachometer configuration; I will assemble a connector (8-pin Bluedash) with CANBus-safe cable to the tachometer; I will post a picture of the tachometer working on my V7 III Stone; I will send you the tachometer with cable and connector; and you will repay me Speedhut's tachometer cost plus up to 30% for parts and shipping (I'll provide an invoice).  If the tachometer doesn't work for you, you pay nothing except return shipping, no questions asked.

If I can't post a picture of the tachometer working, you pay nothing and I eat crow.

GTM provides dual gauge mounting at https://gtmotocycles.com/collections/all-products/products/gt-motocycles-v7-iii-speedo-drop-bracket

* the US-only exception is Kiwi_Roy.  Even if he isn't the first to accept the offer I'll build one for him.

In my mind, where MG missed it was not offering a digital readout of the tachometer on the speedo like they offer odometer, trip meters, average economy, instant economy, temperature, etc.  The information is available and could have easily been implemented.  I've test ridden many single gauge bikes with digital tach on the display.