Quick note about PowerVision tune files from DJ or FuelMoto

[FuzzyWuzHe]

My standard gauge setup usually include engine and head temp (front cyl only), front and rear knock counter, ambient air and intake air..

Okay feeling stupid, what's a knock counter and what's the difference between ambient air and intake air?

 

[scooterbum46]

Okay feeling stupid, what's a knock counter and what's the difference between ambient air and intake air?

The Delphi ECM uses a technology called Ionization Current Sensing to detect preignition ( in simple terms it puts a DC current onto the plug wires and detects the amount of resistance to conduction after combustion - a flame will conduct current, that's how the automatic reignitors work on gas water heaters in RVs, etc). When the measured values fall within set parameters that indicate preigniton or cylinder pressures approaching preignition, the ECM backs the spark advance down until the event is past. The Knock Count is a record of those events, and is cleared when the ignition is shut off. Note that in the BIG PV thread on that other forum, I've asked a couple of questions about this..

Ambient air temp is from a sensor on the bike, measuring temperature of the air in the immediate area of the bike. Intake air temp is measured by a sensor on the intake tract and shows the temp of the air coming in through the AC. Set at a busy traffic light through a couple cycles and you'll see the difference - on a 90 degree day, I've seen IAT as high as 180 degrees...

 

[FuzzyWuzHe]

The Delphi ECM uses a technology called Ionization Current Sensing to detect preignition ( in simple terms it puts a DC current onto the plug wires and detects the amount of resistance to conduction after combustion - a flame will conduct current, that's how the automatic reignitors work on gas water heaters in RVs, etc). When the measured values fall within set parameters that indicate preigniton or cylinder pressures approaching preignition, the ECM backs the spark advance down until the event is past. The Knock Count is a record of those events, and is cleared when the ignition is shut off. Note that in the BIG PV thread on that other forum, I've asked a couple of questions about this..

Ambient air temp is from a sensor on the bike, measuring temperature of the air in the immediate area of the bike. Intake air temp is measured by a sensor on the intake tract and shows the temp of the air coming in through the AC. Set at a busy traffic light through a couple cycles and you'll see the difference - on a 90 degree day, I've seen IAT as high as 180 degrees...

Okay ... I kinda sorta got that ... not sure why I'd care what the knock count is, unless there is a way to adjust the tune to reduce/eliminate it. The two air temps I can see monitoring.

 

[Sloufoot]

Okay ... I kinda sorta got that ... not sure why I'd care what the knock count is, unless there is a way to adjust the tune to reduce/eliminate it. The two air temps I can see monitoring.

The consistent knock count in any area of RPM & throttle position can indicate a lean area, or too much spark advance in that area.
In any areas where you happen to be getting a lot of knock should be addressed to prevent damage. Now that being said, the sensor can also have false knocks. Also a faulty plug wire can give false indications but still work for running the engine. Just a wrong resistance can do this.

 

[FuzzyWuzHe]

The consistent knock count in any area of RPM & throttle position can indicate a lean area, or too much spark advance in that area.
In any areas where you happen to be getting a lot of knock should be addressed to prevent damage. Now that being said, the sensor can also have false knocks. Also a faulty plug wire can give false indications but still work for running the engine. Just a wrong resistance can do this.

So basically ... If I was to notice this knock count go up ... I should check wires and have someone who knows how to tune check it?

 

[Sloufoot]

So basically ... If I was to notice this knock count go up ... I should check wires and have someone who knows how to tune check it?

Well if you are getting a lot of knock picked up by the knock sensor find out where it is coming in( throttle position& RPM) then look at your tune in the WinPV program to see if there is a real lean area in those spots, or if the spark is set real high there.
You might be causing the knock (pinging) yourself also by either lugging the engine, or a rapid switch from decelerate to accelerate with the throttle can also give a knock indication.
The plug wires would be the last thing I would look at if I found nothing elsewhere.
One drawback to the knock or ping is if the ECM sees it too often in an area it will retard the timing in that area. This can happen even if the timing isn't the problem. It takes 10 cycles of the ignition to erase the retard back to the setting in the tune.
The ECM can retard the timing to a maximum setting in the tune, but it can't advance it for you.
If you decide to check the wires, you need an ohm meter to check that the resistance is correct in each wire. The values are in the shop manual. I don't want to quote the amount from memory with that working the way it has lately !

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Fuzzy, unless you are getting a constant pinging in an area, or a lot of pings kinda all over I wouldn't worry about a few here & there.

 

[msocko3]

Fuzzy, unless you are getting a constant pinging in an area, or a lot of pings kinda all over I wouldn't worry about a few here & there.

It wouldn't hurt to check for any knock activity, at times there can be some knock without it being audible.

The guy who this piston belonged to never heard the knock, until it trashed the piston. He was lucky the piston is forged, a stock cast piston can crack.

 

[scooterbum46]

Okay ... I kinda sorta got that ... not sure why I'd care what the knock count is, unless there is a way to adjust the tune to reduce/eliminate it. The two air temps I can see monitoring.

If you've got a totally stock bike, and trust that the "one size fits all" map that HD supplies, I guess you might just ignore knock count, but if you've got the tool to see it and understand that the stock map may have deficiencies, you use the tool.

In my case, this is the third 103 that I've had and had the PV on (yup, relicensed twice). The trike is going to get the same treatment as the other two (FM AC, Jackpot 2-1-2 and on this one E-series mufflers), but until I return home from FL, I just put the PV on. I immediately noticed front cylinder knock detection beyond what I considered normal and decided to load the FM (and DJ) supplied "improved stock" map and do some monitoring, before starting to AutoTune. I've now progressed to the point after two AT sessions where it looks like it's under control. But I guess to answer your why - I guess because I don't like holes in the tops of pistons and once you move away from the conservative maps that HD uses, anything, including holes in the pistons is possible..

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It wouldn't hurt to check for any knock activity, at times there can be some knock without it being audible.

The guy who this piston belonged to never heard the knock, until it trashed the piston. He was lucky the piston is forged, a stock cast piston can crack.

View attachment 26469

Yeah - that.... I see you were answering at the same time I was cogitating..

 

[FuzzyWuzHe]

Okay ... so monitor the knock count and look for changes ... or rpm/throttle positions where it seems to be more ... when I find these conditions come to the forum .... raise my hands and scream for help ... got it.

 

[Sloufoot]

Okay ... so monitor the knock count and look for changes ... or rpm/throttle positions where it seems to be more ... when I find these conditions come to the forum .... raise my hands and scream for help ... got it.

Fuzzy, run with your PV on & the knock sensor where you can see it & watch. It will show you in real time what it sees.
There are procedures with the PV to run timing runs to find the optimum timing. It would be worth your time to read up on it & give it a try.

 

[FuzzyWuzHe]

Fuzzy, run with your PV on & the knock sensor where you can see it & watch. It will show you in real time what it sees.
There are procedures with the PV to run timing runs to find the optimum timing. It would be worth your time to read up on it & give it a try.

Where do I go to read up on it

 

[Sloufoot]

It wouldn't hurt to check for any knock activity, at times there can be some knock without it being audible.

The guy who this piston belonged to never heard the knock, until it trashed the piston. He was lucky the piston is forged, a stock cast piston can crack.

View attachment 26469

ThumbUp:Agree:

 

[scooterbum46]

Just a follow up - the hi knock count on the front cylinder that I was chasing is cured - swapped plugs back to front and the hi count moved to the back. New plugs and everything looks normal (2500 miles on the old plugs). When it was doing the knock sensing on the front, it was pulling timing. Gotta love tools like the PowerVision that show you more of what the ECM is seeing!

:clapping:

 

[HarleyPap57]

I decided that the tiny error I was seeing in speedo/odomerter was unsat, so ... I started play with the speedo numbers ... I wasn't sure whether I needed to add or remove pulses to correct it. What I did last night was to start with 2462 what was on my original tune, and create copies of the map with +12 and -12 or 2474 and 2450 ... then -24 and +24 or 2438 and 2486. What this did was to allow me to reflash on the highway (pull off an exit, go on the overpass, reflash and head the other direction). Probably can't do that back east ... get run over.

Here I loaded one ... ran for about 30-40 miles checking speedo against gps and odometer against mile markers. I know ... this is probably the long way around the block as my dad would say ... bottom line .. I used to have a 0.3 mile error in 10 miles ... the 2450 map was the closest, but the 2438 was too low ... with the 2450 map my error is now 0.2 miles on 40 miles. Pretty close .. less than a mile on 100. Maybe I'm anal, but tomorrow I'm doing the same thing but with maps at -2, -4, -6, -8, -10 ... I'm guessing -4 will be perfect, but we'll see. Gives me an excuse to ride ... not like I needed one.

Guess I really need to do some reading on using the PV. I ran the AT before we left for Savannah, saved it and then flashed the new one but could not get it the flash the tune again. After reading this though I did check my speedo and odometer and they are with 0.3 miles after 20 miles. Once I figure how your doing yours I may try to get it closer. Love reading your threads..ThumbUp

 

[FuzzyWuzHe]

Love reading your threads..ThumbUp

Thanks ... I love messing with the bike ... although .. the PV scares me a little .. you can do some real damage if you get into some of the deeper stuff ... as a rookie, I'm sticking to easy stuff to adjust .. so far just doing auto tuning and the speedo calibrations ... also some monitoring ... I love knowing what's going on behind the scenes.