so when you plug your FP3 into the CANbus you get a tach readout, is that an option? Somehow plug the Police tach into the the CANbus port and get a clean signal?
just a rhetorical question, I know and have read Max's solution
The dealer said I can't wire a tach to the coil because it will mess up the computer. I asked why the police bikes have separate speedo/tach, the other touring bikes have a separate tachometer, but this same engine and year motorcycle- you can't do it (??).
You could make 1000 dollars producing this tach you designed yourself as hundreds of people across the country want this.
When I saw your tach and code writing abilities, my jaw dropped. This is exactly what I need.
I contact HD and they tell me to buy the drop-in combo tach/speedo.
What good does that do? Makes everything smaller. The whole point of a handlebar tach is: Safety- keeps my eyes from looking down at this LCD screen all day when touring and keeps my eyes near the road.
My coils do not have any terminals (that I can see) to connect the tach to, either.
Man. This really sucks that for 30 years I've had tachs on my handlebars. I go out and spend 30 grand on a RK and find out after the sale that it can't be done.
PS. like everyone else is saying...you are a genius.
I doubt that adding a wire to the primary on an M8 hurts anything. I suspect that the dealer is really concerned about messing with Delphi ion sensing that was used on twincams. One thing to note is that the M8s don't use ion sensing. The M8s use a dedicated knock detector. The result is that the coil wiring does not include the ION sense line. If you need isolation add a 1K ohm resistor in series to the tach. You'll need a single fire converted but a cheap tach is under $100.. If it works you could go to a nice auto-meter.
I agree with tach placement. The only time you need to look at speed is when there is a black and white around.
If the reference is to me, Not a genius but more of a hack.. I've not used CAN bus very much before this.. Understand the hardware level pretty well Software and protocols I'm pretty weak. I can muddle through it and make things work sometimes..
so when you plug your FP3 into the CANbus you get a tach readout, is that an option? Somehow plug the Police tach into the the CANbus port and get a clean signal?
just a rhetorical question, I know and have read Max's solution
Sure you can.. Not sure if you can set the display up to show a needle tho.
Hey Max.
I'm going with the autometer tachometer you suggested with the autometer cup and 1k ohm resistor to isolate tach.
My questions are:
1. Do I use a Wire wound resistor or carbon film resistor?
2. In series? Does that mean solder the resistor in the middle of the tach signal wire?
3. The "primary tach wire"? On my coil, I have one connector with 3 wires. The middle wire is power to coil. The outside wires are to the front and rear cylinders. Do I tap into the front cylinder wire only and then solder a resistor into this wire?
If so, the tach connections would be:
1 .Tach signal wire from tach with a resistor inline to the front cylinder (Green/Beige?) wire that runs between the coil and the ECU box.
2. 12v and indicator lamp wire to +12v.
3. Black ground wire to chassis ground.
Last edited by billyo00769; 11-29-2018 at 08:53 AM.
Hey Max.
I'm going with the autometer tachometer you suggested with the autometer cup and 1k ohm resistor to isolate tach.
My questions are:
1. Do I use a Wire wound resistor or carbon film resistor?
2. In series? Does that mean solder the resistor in the middle of the tach signal wire?
3. The "primary tach wire"? On my coil, I have one connector with 3 wires. The middle wire is power to coil. The outside wires are to the front and rear cylinders. Do I tap into the front cylinder wire only and then solder a resistor into this wire?
If so, the tach connections would be:
1 .Tach signal wire from tach with a resistor inline to the front cylinder (Green/Beige?) wire that runs between the coil and the ECU box.
2. 12v and indicator lamp wire to +12v.
3. Black ground wire to chassis ground.
1 Use the metal film. Wire wounds can be inductive.
2. In series placed near the coil.
3. Front or rear cylinder wire is fine. Which one don't mater.. The autometer tach needs to support 1/2 pulse per RPM.
The autometer tachs are 1 or 2 pulse per revolution. When you say 1/2 pulse per revolution do you mean set it on 2 pulses?
Also, some people are saying to wire the resistor from +12v (red) wire to the green tach signal wire.
But that would be a step-up resistor to give the signal wire more voltage (that can't be correct)
I am assuming that you mean a resistor on the green (tach signal wire) only - near the coil.
I have sent AutoMeter an email on the 1 or 2 pulse per revolution question.
Last edited by billyo00769; 11-29-2018 at 12:25 PM.
You want the resistor near the source of the signal.. Ideally you may not need it but it helps to keep the signal from interfering with other systems.
I mean 1/2 as in 0.5 pluses per revolution.. In other words if the tach sees 500 pulses per minute, it will read 1000 rpm. Some Autometer tachs do it, others do not (IIRC).
Yeah. I had to go with speedhut 3 3/8 tach. That one is programmable to 0.5 PPR.
Finding the threaded cup and mount is the difficult part.
Do I take your cup design schematic to a machine shop like napa? Or just pay you for your time parts and shipping??
I'll figure it out somehow.
Thanks again for all the help.
Yeah. I had to go with speedhut 3 3/8 tach. That one is programmable to 0.5 PPR.
Finding the threaded cup and mount is the difficult part.
Do I take your cup design schematic to a machine shop like napa? Or just pay you for your time parts and shipping??
I'll figure it out somehow.
Thanks again for all the help.
You have to take it to a job shop machine shop. Napa likely mostly does automotive type machine work.
I browsed the Autometer stuff and they do make some 0.5 PPR tachs. I guess they don't make one top dash mount?
Hey Max.
Yeah Autometer makes one but the speed hut looks cleaner.
The autometer goes to 10k RPM. I'll never use half the gauge, lol.
Here's a pic:
The speedhut matches the Harley speedo better. Looks clean. You picked the best for the Road King, I think.
My bike looks pretty close to yours.
I just changed all my lights to LED (headlight, passing lamps, turn signals, brake light)
Wow. What a difference! I can see and be seen so much better. Also, the electrical draw is about 1/3 of the stock lighting.
Have you checked into the LED lights yet??
Here's the Before Pic: After Hogworkz black halo headlamp and passing lamps
11-08-2018, 12:02 PM
