Hi there!

I am pretty done with my map (2014 FXSB Breakout with 103B engine, AN Big Sucker and "gronk" OEM slip ons) but I have some concerns about some spark knock signals @3000rpm in 6th gear. The knock counter on my Power Vision gauge set is rolling (mostly on rear cylinder but also some in front) but I can't hear any pinging sound! Opening logs with MegaLogViewer shows that spark advance correction occur for maximun 2.5/3 deg.
I'm happy with the map because the bike is really ok, I'm just concerned about those knocks.
I do not have very aggressive spark advance and my tuner is telling me not to care about this but I do not want to damage my engine.

Any hint?

THANKS!
Andrea

 

You can't always hear it

 

I sent my map and logs to Dynojet and Roy answered me:

[...]Keep in mind your bike uses what is called an Ion sensor, not a real knock sensor. The Ion sensor measures how much energy is needed to fire the spark plug; any difference in combustion pressure can change the energy needed to fire the spark plug. If you are not hearing engine knock, when you are getting knock hits, they are not real knock events. If that is the case, you don’t need to do anything.[...]

This is exactly what my tuner told me, I think I will stay with my map, remove that PV from my handlebar and ride and have fun as much as I can!

 

Good info!

The ECM, using the Ion sensing, knows when a "ping" is about to occur and will retard the timing to prevent it from occurring. These new Twin Cams should never ping, UNLESS, the tune is so far off/or the gas is so bad/the engine is so hot, that the ECM cannot retard the timing enough to prevent it.

 

The ion sensing is a reaction. It doesn't predict.

 

It is almost impossible to answer one of these questions without the owner posting a data log off a Powervision or TTS.

 

For example this

 

Here is what you knock looks. Deep Blue is no knock reported.

Most of your knock is located in a small area of the map and mostly at WOT

http://www.nbs-stl.com/HarleyTuning/...ockScatter.png

I used MegaLogViewer HD to open all of those logs at the same time to generate this plot. It opened right up.

Hope this helps

Andy

 

It's a huge help! What do you suggest? Remove advance is the cure but where? How much?

 

I don't do any tuning anymore without having a way to look at the data in 3D. I use MLV HD on almost all of the systems I tune on. It only costs like $40 for the full licensed version. I can help you get started.

I would pull about a degree of timing in the effected ares on the front and about 2 degrees on the rear. From about 92 KPA and 2300 RPM up to about 100 KPA and 3500 RPM.

Andy