Know the Harley Plug has 1/2 the resistance in the look a like NGK plug.
TC -ION Sensing Detection Explained
Cruiser
Joined: Nov 2010
Posts: 210
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From: Phoenix AZ
The knock sensor system is a good thing to not mess with. If the spark settings & fuel settings are set correctly there won't be any knock with the standard knock sensor settings.
One other thing to check is the plug wires to see that they are the correct resistance. Many aren't correct new.
Even the spark plugs are different I checked the ohms on plugs some I had they all are a little different.
I wonder since resistance can vary a lot! they may have a wide range programed into the ecm ?
Cruiser
Joined: Nov 2010
Posts: 210
Likes: 0
From: Phoenix AZ
The only problem with the pro and tts tuner is it is not like the flash tuners, you have to make changes your self and then ride the motorcycle and do your data recording and see what needs to be changed, unless you are lucky enough to have access to a dyno, witch is what those tuners are made for. The flash tuners you load a preconfigured map and then either do an auto tune or a seat of the pants tune, either way if you start to change stuff on the bike ESPECIALLY the air filter/intake you need to tune it.
Extreme HDF Member
Joined: Aug 2013
Posts: 16,271
Likes: 15,108
From: Somewhere SW
Interesting read, the way I've come to understand ion sensing is that a second flame front builds up ions across the spark plug, the ecm detects the event and makes adjustments accordingly
I was always under the impression that mechanical changes and air/fuel mixture would be irrelevant.
I was always under the impression that mechanical changes and air/fuel mixture would be irrelevant.
Cruiser
Joined: Nov 2010
Posts: 210
Likes: 0
From: Phoenix AZ
Interesting read, the way I've come to understand ion sensing is that a second flame front builds up ions across the spark plug, the ecm detects the event and makes adjustments accordingly
I was always under the impression that mechanical changes and air/fuel mixture would be irrelevant.
I was always under the impression that mechanical changes and air/fuel mixture would be irrelevant.
So in other words if you start to change air filter cam or exhaust, the motor needs to be tuned.
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,062
Likes: 7,591
From: Poolville
I know how it works , it just amazes me cause the front plug wire is longer the the rear, there fore the resistance will be different , but I guess that is all programed in to the ecm.
Even the spark plugs are different I checked the ohms on plugs some I had they all are a little different.
I wonder since resistance can vary a lot! they may have a wide range programed into the ecm ?
Even the spark plugs are different I checked the ohms on plugs some I had they all are a little different.
I wonder since resistance can vary a lot! they may have a wide range programed into the ecm ?
Cruiser
Joined: Nov 2010
Posts: 210
Likes: 0
From: Phoenix AZ
When you are looking at the sespt tuner all it will let you do is stay within the EPA standards.
On an engine that is already lean from factory almost anything you change will make it run leaner. .
If your plug is white white you most likely need more fuel in those knock areas. Not much of a change can be enough to take care of it. Sometimes it does take a large adjustment in both spark & fuel .
But remember what tuner you have........ Also get a lot of reading in the tuning forums & ask questions. !
On an engine that is already lean from factory almost anything you change will make it run leaner. .
If your plug is white white you most likely need more fuel in those knock areas. Not much of a change can be enough to take care of it. Sometimes it does take a large adjustment in both spark & fuel .
But remember what tuner you have........ Also get a lot of reading in the tuning forums & ask questions. !
I dont know why people say the stock motorcycle is set from the factory lean the plugs I got out of my streetglide are perfect and the bike had no mods!, the one on the right is lean and has a lot of mods.
and that is why I am here to read the tuning fourm. it is helping.
Cruiser
Joined: Nov 2010
Posts: 210
Likes: 0
From: Phoenix AZ
Do you really think the ecm can read the resistance of your wires? Let alone make an adjustment? and what would that adjustment be? I believe what Sloufoot was referring to was that make sure you have the right type of plug wires. The standard does not apply any more.
as far as reading the resistance of the plugs and wires, not really I think like Sloufoot said out of the box sometimes the resistance is out of spec. I think like JustDave13 described it in a more simpler way than HDF Tech did. when the knock or pre ignition occurs it increases cylinder pressure and some how sees it needs more voltage to fire the fuel because of the increase in needed voltage to fire the plug. maybe it sees the dwell or the time the spark takes to jump the plug gap.
If it was a car you could hook up a scope and see the pattern and see by the voltage from the firing event what is happening in the cylinder. I guess the computer is doing the same thing reading the voltage.
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Extreme HDF Member
Joined: Aug 2013
Posts: 16,271
Likes: 15,108
From: Somewhere SW
Do you really think the ecm can read the resistance of your wires? Let alone make an adjustment? and what would that adjustment be? I believe what Sloufoot was referring to was that make sure you have the right type of plug wires. The standard does not apply any more.
well the adjustment would be a retarding of the timing.
as far as reading the resistance of the plugs and wires, not really I think like Sloufoot said out of the box sometimes the resistance is out of spec. I think like JustDave13 described it in a more simpler way than HDF Tech did. when the knock or pre ignition occurs it increases cylinder pressure and some how sees it needs more voltage to fire the fuel because of the increase in needed voltage to fire the plug. maybe it sees the dwell or the time the spark takes to jump the plug gap.
If it was a car you could hook up a scope and see the pattern and see by the voltage from the firing event what is happening in the cylinder. I guess the computer is doing the same thing reading the voltage.
as far as reading the resistance of the plugs and wires, not really I think like Sloufoot said out of the box sometimes the resistance is out of spec. I think like JustDave13 described it in a more simpler way than HDF Tech did. when the knock or pre ignition occurs it increases cylinder pressure and some how sees it needs more voltage to fire the fuel because of the increase in needed voltage to fire the plug. maybe it sees the dwell or the time the spark takes to jump the plug gap.
If it was a car you could hook up a scope and see the pattern and see by the voltage from the firing event what is happening in the cylinder. I guess the computer is doing the same thing reading the voltage.
From I remember this ion front is picked up across the spark plug gap inducing a voltage back into the coil. The ecm picks up this charge and sees it as a detonation event.
IIRC
This technology is evolving
Last edited by JustDave13; Jun 9, 2015 at 10:56 PM.
Extreme HDF Member
Joined: Aug 2013
Posts: 16,271
Likes: 15,108
From: Somewhere SW
Here's an article that puts it in simple terms
http://www.searchautoparts.com/motor...nse-technology
http://www.searchautoparts.com/motor...nse-technology