TTS ION Sensing Data Runs

[wurk_truk]

OK

Do the spark plug wires themselves effect the ION sensing?  There has been discussion that the plugs can effect ION sensing.

I had a miss.  The dealer had SE plug wires and not the OEM wires and I switched (helped the miss BTW).

So, during a DATA run, would the wires themselves effect the ION sensing portion of the run?

[eddfive]

Yes, it can be wires and/or plugs.  I use only stock 6R12 plugs and stock OEM wires.  I have had issues with all types of other plugs and with SE plug wires. 

[springer-]

In theory any direct replacement plug should work.  With that said we have seen issues with the ECM erroneously taking 8-12 degrees of timing out due to a perceived spark knock.  Installing stock plugs and wires has always corrected this for us.  Because of that we always recommend stock wires and plugs, just prevents issues.

[wurk_truk]

Thanks!!!

[nc-renegade]

I have stock plugs and wires.  Yesterday, was tuning WOT, (my VTune session had tuned in excellently).  We notice the ION sensing was taken out 8 degrees of timing and my torque was all to hell.  I had modest timing at WOT....22 degrees of advance.

We turned off the knock sensor and low and behold, the torque came right up.  We added timing (26 degrees), turned on the knock sensor and all was well.

The tuner is real good (Brian from T-Man Performance) and he said he has seen this before.....overly retarded timing causing the ion sensing to retard even more.

This leads me to believe that just arbitrary taking timing out due to knock sensing might not always be the best move.  Really have to look at the torque at that RPM as well.

It was eye opening experience for me.

[glens]

The Ion Sensing doesn't check for spark knock, it checks for "funky combustion event", so this stands to reason.  It's also why I advocate leaving the circuit parts (plugs/wires) the way they came from the factory, since we don't have access to calibrate the programming for it.

"With Delphi's Ion Sense technology, the conventional spark plug acts as an intrusive sensor in the cylinder to obtain information about each combustion event..."

I also think it might not be a very good idea to mess around with the spark timing using a piggyback controller.

[FLTRI]

The Ion Sensing doesn't check for spark knock, it checks for "funky combustion event", so this stands to reason.  It's also why I advocate leaving the circuit parts (plugs/wires) the way they came from the factory, since we don't have access to calibrate the programming for it.

"With Delphi's Ion Sense technology, the conventional spark plug acts as an intrusive sensor in the cylinder to obtain information about each combustion event..."

I also think it might not be a very good idea to mess around with the spark timing using a piggyback controller.

Been preaching this for years. 
Bob

[wurk_truk]

I also think it might not be a very good idea to mess around with the spark timing using a piggyback controller.

I agree completely on this statement.

Also, even tho WE can't see a difference between the SE and the OEM, I bet there IS one, and why I asked at all.

Thanks, and will order a set of OEMs ASAP.  I wish to utilize each and every function of my Mastertune to its fullest extent.  Data acquisition and using that data for small changes is HIGH on my list right now.

(Bob, you have answered my First question, Thanks).

[Bagger]

From Mike Stegman
Latus Harley Davidson: 9/3/09
http://www.v-twinforum.com/forums/1668889-post133.html

In the most simplistic terms, ION sensing is no more than reading the amount of resistance that must be overcome to fire the plug. This can be measured by the residual amount of ION's after fireing the plug. This can change with plug gap, plug age and (most importantly for us) cylinder pressure. The higher the cylinder pressure the higher the resistance the plug "sees". This is why high compression motors tend to give false knock detection. To activate an engine code requires parameters to be set (I.E. a high and low resistance value) for the ECM. These tend to be for stock engines but experiance seems to indicate they are wide enough for most SE engine builds (which tend to stay below 11:1 compression). Even HD will suggest that Knock Control be turned off for compression ratio's above 10.5 (more accurately, the dynamic cylinder pressures associated with the compression/cams/motor size/chamber volume/piston shape-area/rpms/etc.).


Just wanted to throw this out for thought. What did carb'd bikes do before ion sensing for knock detection, probably tuned to prevent knocking....... If carb'd bikes didn't have anti knock sensing, then in efi bikes that have been built up from stock, why not just have the engine tuned properly and turn off the knock control.....

[wurk_truk]

why not just have the engine tuned properly and turn off the knock control.....

Why would you?   Knock control helps one look for an 'event' while doing data runs with a TTS, which this thread encompasses.  Also, why do it anyways.  Does you car have a 2bbl carb on it anymore?  Why not?  your car has knock control and so does everything else... allows an engine to be tuned to a more efficient state.  In this day and age... how can ANYBODY tune properly?   Go look at the gas that is sold around the country anymore.  Sure, maybe if you stay within 100 miles of home, you could tune for your gasoline, but if you travel, knock control is like sliced bread.

[Bagger]

wurk_truk, all good points, alright how about - 

The Harly ion sensing system is a very good system and very reliable with one HUGE exception. Detection is dependant on the values calibrated in the software that represent knock, and are based on a stock engine ( or a known modified engine such as the STAGE I,II etc.) with a GIVEN set of Production intent parts.ie , Spark plugs, wires, and even compression ratio can and does change the resistance at the coil. So once folks start changing wires, Plugs ( to non-factory specs) and modifing the engine cams, compression ratio etc,( and even expected A/F ratios, and therefore combustion temperature) the values derived form a production engine are no longer valid and may cause the software to "determine" that knock is present when it's not or fail to dectect knock when it is.

[glens]

From Mike Stegman
Latus Harley Davidson: 9/3/09
http://www.v-twinforum.com/forums/1668889-post133.html

In the most simplistic terms, ION sensing is no more than reading the amount of resistance that must be overcome to fire the plug. This can be measured by the residual amount of ION's after fireing the plug.

I doubt that's hardly even close.  Maybe he's just trying to say something that he feels simpler folks can walk away with feeling like they understand.  Look at http://delphi.com/shared/pdf/ppd/pwrtrn/gas_ignics.pdf at the top of page two.  There's a (generic) circuit diagram there.  The capacitor which powers the "Ion sensing" mode is charged while the spark is occurring and the sensing circuit only operates for a very short time afterward while the capacitor bleeds back down.  There's no way it's going to tell you anything about how much current is required to spark the gap.  The capacitor gets its charge right off the top of what's available in the first place.

Now it stands to reason that this circuit will produce whatever signal it's going to produce whether the spark timing has been altered between the ECM and the coil (like with a Power Commander [or Fuelpak?]), but I'd bet the ECM is looking at the output of the circuit at a fixed point after it sent the spark signal, so it may or may not be reading the "Ion Sense" at the time it's happening if that time has been stretched or shortened by something else unbeknownst to the ECM...

[wurk_truk]

wurk_truk, all good points, alright how about - 

The Harly ion sensing system is a very good system and very reliable with one HUGE exception. Detection is dependant on the values calibrated in the software that represent knock, and are based on a stock engine ( or a known modified engine such as the STAGE I,II etc.) with a GIVEN set of Production intent parts.ie , Spark plugs, wires, and even compression ratio can and does change the resistance at the coil. So once folks start changing wires, Plugs ( to non-factory specs) and modifing the engine cams, compression ratio etc,( and even expected A/F ratios, and therefore combustion temperature) the values derived form a production engine are no longer valid and may cause the software to "determine" that knock is present when it's not or fail to dectect knock when it is.

I will go with most of this.  And it is the WHY I asked about plug wires.  I agree with a 'diminishing returns' as the engine grows away from stock.  I also think that would have to do with compression more than anything else.   Taking what you quote and what Glens says... "something" is used to determine an 'event'.  Increased compression can surely effect that.

I'm old enough to firmly remember tuning with different weights in a distributor.  I LIKE this stuff way better, and feel it controls spark, etc way better, too.

Other vehicles also use vibration/audible, or whatever they mount in cylinder blocks, type sensors for knock, so I would have to agree that ION sensing isn't the end all to be all.  Because I am kind of a dumbass, know what I think is pretty cool?  The ECM can tell if one is hanging a plug on the wire looking at spark.  The ECM can also tell if you have the plugs out, and won't fire the injectors.  Now, does it do that with ION sensing (low resistance to the spark jumping the gap), or also uses the MAP sensor?   I don't know, and AM a bit curious.

Anyway, everybody has answered my original question.  Having a tuning issue or three and wish to do a few data gathering runs.  Want the best available info, if I do those runs.  I NEED OEM plug wires for this.