Does anyone remember the method used by your tuners to connect the dynojet rpm sensor to the V-Rod?

The two dyno runs I've done so far used dynos that calculate the rpm based on wheel speed and an adjustment value. I have a session setup for Friday on a Dynojet.

I remember people talking about running a wire from the #3 wire in the ECM connector but I don't have the correct connector ends to make up a wire and it looks like the Dynojet uses an inductive pickup that may not work with a direct connection. I know the coil primary's run from the ECM (pins 10 and 28) so maybe isolating these wires in the harness and using the dynojet primary induction pickup is the least obtrusive way to go.

Thoughts?????

Mark,
I shoulda paid a little more attention when I had mine dynoed.All I know is that they hooked up to a wire on the rear coil.I wanna say a white or tannish white wire.I won't bet the farm on which wire it was,but I now it was on the rear coil.It was a dynojet.
Sorry.

That would be the primary for the rear coil. Good deal, I wasn't looking forward to opening up the connector on the ECM :thumb:

If you do decide to use the ECM for data Mark it is terminal 3 on the ECM.

Max,

Thanks, the only problem with tapping into the ECM is I don't have the correct connector end for the wire (my connector is empty in the #3 slot). Where would I be able to one fast? Does Radio Shack carry them?

No they are Hewlett Packard ends and I'm not sure of the exact number.

Max

Mark
it's easy as Vinny said just clamp to wire on rear coil .The problem I had thoght on Big HP Runs we would not always get RWTQ that way.At the dealership with used the wire off the ECM and TQ readings were great! :kaz:

The 2 different dealers I went to used a wire on the rear coil.Neither place had trouble reading rwtq.Maybe it's something in the software from dealer to dealer.
I thought A signal was a signal. :hmm: Does it really matter where the signal is?just as long as you get one. :confused:

Am I missing something here?
:confused:

No, you're not missing anything. I bet that if you don't isolate the coil primary and just put the inductor pickup around the wire bundle then it will pick up noise, especially if your on the verge of detonation since the bundle also carries the ion sensor lead. That's the only reason I can think of where you would have trouble staying locked onto an rpm reading (which is what's needed to calculate HP, not torque). ;)

HP = (TQ*RPM)/5252

Mark,
So if I wanted a true torque reading,Then I would do like Kaz says?Will that way still calculate HP?I always thought the dyno reads both tq and hp with the drum(brake)?
So which way would be the better way?Is this one of Kaz's secrets to HP?

No, the dyno will always display torque, that's the only thing it really measures. It needs the engine speed to calculate HP. It doesn't matter how you calculate engine speed so long as you can capture it simultaneously with the torque. Kaz's issue was the RPM reading wasn't stable, either cutting in and out or the sensor was getting multiple signals. Hooking up directly to the tach output on the ECM eliminates the noise and allows the dyno's computer to do the HP calculations with a clean rpm reading. There are other dynos that don't use the RPM lead, they calculate rpm based on the rpm of the drum. It's a simple calculation as long as you know the conversion factor. On the Factory One / Mustang dyno the computer has a setup routine where you run the bike at a given rpm on the tach, look at the effective rpm readout and adjust a variable until the two match. No tach hookup required.

I got a reply from dynojet, they said to use the primary inductive pickup on the only primary wire feeding the rear coil pack. I seem to remember that Kaz had a rear coil pack go bad, that might have been the first symptom.

Mark,
you know I'm not the Tecnoid your are so if you would like his personal cell number I will give to you off line.I only know what I have seen! :kaz:

p.s boy do I have some racing gossip and it'd BIG TIME!Harley is in town doing some Top Secret Vip Testing with the competetors bikes for comparison?Yes there is a V-rod with the Baddest SHOE in the Country here too! ;)

Kaz,

No problem, in fact, after re reading your post I see the measurement was RWTQ. That's another calculated variable that uses the rpm. Absolute torque is the basis for all the calculated measurements. We'll see how my "mere mortal" V-Rod handles the inductive pickup ;)

p.s boy do I have some racing gossip and it'd BIG TIME!Harley is in town doing some Top Secret Vip Testing with the competetors bikes for comparison?Yes there is a V-rod with the Baddest SHOE in the Country here too! ;)
Tell us more. :D

Mark, I think I got it.
Thanks,