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Discussion Starter · #1 ·
OK so I fell for the sales blurb and purchased a pair for my next service. Before I fit them I was concerned to see Mark's post and a couple of others on different threads that seem to suggest that these can cause problems??

Whats the verdict guys do I fit em or stick with the standard HD issue?

Thanks Jon
 

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jon...i used ngk plugs in the car trade for years and never had a problem, and all my bikes have had them too, when the vee is ready thats the brand i am considering putting in.
personally i am a fan of conventional plugs and will only put iridium plugs in if there is no other choice
remember that the US bikes differ from ours due to mapping, emissions, altitude and temperature ranges so what may work for our American friends may not work for us.
 

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Crash Bandacoot
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I run Iridiums in my '86 Yamaha Maxim X.
The bike has almost 15k on the odo,and runs strong.
I have noticed better acceleration and faster warm-ups< also water cooled> with the Iridiums.
At 4 bucks a pop..I'll prolly get a set for the V when the time comes.
 

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Trailers R 4 Boats
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I ran Iridium plugs in the DX for my run to Texas, 3,900 miles in all, bike ran great!
 

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Discussion Starter · #7 ·
Will do. I have always used the rule of thumb that around 10K is a good time to change for normal riding and standard motor. There's nothing wrong with leaving them longer but if you experience misfires, erratic pulling etc a good place to check first is for fouled/knackered plugs.

I am expecting the current plugs to be Ok when I pull them but I am interested to see if there is any noticeable difference with the Iridiums.

Keep you posted
 

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I have read numerous times that you should stay with the stock plugs on these bikes. The reason is the ion sensing knock control system used in the Delphi ecm. It seems that "some" aftermarket plugs can cause problems and you end up with a bike that runs poorly. The knock control system measures the impedance of the plugs and they are not all the same. You can always try it and see what happens but I would stick with what is known to work. Later.
 

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20 Eyes in my Head
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HokieRich said:
I have read numerous times that you should stay with the stock plugs on these bikes. The reason is the ion sensing knock control system used in the Delphi ecm. It seems that "some" aftermarket plugs can cause problems and you end up with a bike that runs poorly. The knock control system measures the impedance of the plugs and they are not all the same. You can always try it and see what happens but I would stick with what is known to work. Later.
:them:

I have yet to read ANYTHING about different sparkplugs in the V doing better than stock plugs and ask HokieRich says, the info I read says specialty plugs f'd up the ion sensing knock control.

Spark is spark anyways...it's just used to ignite an already volatile mix of gas and air. Most of what is out there is creative marketing gimmicks such as that Shitfire...er...Splitfire plug that was out a few years ago. :D

Later
Gary
 

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DungeonWorks said:
:them:

I have yet to read ANYTHING about different sparkplugs in the V doing better than stock plugs and ask HokieRich says, the info I read says specialty plugs f'd up the ion sensing knock control.

Spark is spark anyways...it's just used to ignite an already volatile mix of gas and air. Most of what is out there is creative marketing gimmicks such as that Shitfire...er...Splitfire plug that was out a few years ago. :D

Later
Gary
Well.. I wouldn't say a spark is a spark.. There are definitely various qualities of a spark that make one better than another.. Any racer will know that. Now, for 99% of the people riding Harley's, stock is probably adequate. But for the other 1% that want a cleaner burn and less missing, the spark quality does make a difference.

Not sure on the suitability of the NGK in the V-Rod.. just know from using them in other bikes that I did race there were definite differences.
 

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Discussion Starter · #12 ·
Guys as always a pleasure. I appreciate your input. Now I have parted with the cash I am going to give em a go. I'll post my feedback to let you know. I have to say that fresh out of the box these little buggers do look like they were made for the job:)
 

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The ion knock detection is really MODEL based !!

I wrote a little on the Harely tech talk board a few years ago. ( Probably due to the same confusion )
From: fatboyrr
Sent: 9/12/2003 9:24 PM




Here goes, I'll make it the condensed version. First ION knock detection is the direction most applications are going to use. The old PEZIO sensor relied on a vibration ( caused by some level of knock ) to register at the sensor, It is very hard to detect low levels of knock and seperate the singal ( knock from detonation ) from normal engine vibrations, such as valve closings on a Harley engine. On most vehicle applications the knock sensor can sense true knock from noise, but may not READ every cylinder in a multi-cylinder engine at every cylinder at every RPM, But most system use a GLOBAL retard scheme where any knock will retard spark to all cylinders at the same amount. New systems are going to indidvidaul cylinder knock detection where only the cylinder producing knock is retarded and only until knock ( detonation stops) so in a V8 or V6 you might only have one or two cylinders with any amount of retard.

The advantage of the ION system is it is not dependant on a sensor location and it can be calibrated to detect each cyclinder at all engine speeds and loads.



ION sensing knock detection does not use a Sensor that is externally mounted on the engine. The name ION sensing is derived from the fact that as detonation happens IONIZATION at the plug tip changes the resistence to fire the plug. The actual detection to this change in resistance is internal to the coil and the signal is sent back to the ECM. Software tables are then calibrated using model based software. The way it is calibrated is important to understand WHY some folks are having TROUBLE. A very sophisticated Combustion measurement system is placed on a development engine and actual cylinder pressures are recorded vs. crank angle degrees and coil operating ranges, as the engine is running at set speed and loads. By reading "NORMAL" outputs from the ignition module electronics to the ECM input and noting the change when detonation casues Peak cylinder pressures to rise, a model can be developed that as long as the signal from the ignition module is outputing the "expected NORMAL" signal back to the ECM no retard will occur. A change in resistence value and amount can be correlated to a given rise in pressure in the chamber during combustion. Detonation causes very large spikes in pressure even at very low levels of detonation, so the model can and does detect even before "audilble" detonation ( that which can be heard ) happens. It 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 should.



So Harley knock detection is really not that different than other vehicle manufactures, it's US the users that may not understand the impact on a calibrated system when making major or even minor changes. The STAGE flashes are calibrated to work correctly ONLY with very specific parts. One open exhaust or aircleaner is not the same as another of a different brand.... THE LEARNING CURVE will be steep and there is alot of mis-information floating around.....

Added Today:7-10-07
PLUGS are PART OF THE system. You may not notice if the system is working or not as low levels of detonation are not audible, but can and do cause issues over a longer period of time. Additionally, even LOW LEVELS of detonation in high compression engines can lead to "PRE-Ignition " from hot spots caused from this low level of detonation. Pre-ignition is far more damaging than detonation, as that ( pre-ignition ) is mainly the cause of "HOLED PISTONS".

Just a word of caution !!!
And just because SOMEONE else may have used a different PLUG without issues, does not mean it will work for everyone else. Where, and at what operating range of the engine along with the fuel, are just some of the variables that might allow one to work and one NOT TO work correctly. And one failure of the KNOCK system at precisely the wrong time can have very dire results.
Manufacturer's not only test as many variables as possible, when calibrating an engine, but build in a margin of robustness. And one last point about using OTHERS experience as a basis for no BAD RESULTS. Do you think there are NOT changes to both software and calibrations as standards CHANGE from year to year? Those darned engineers need something to do !!!!
Personally, I see no reason to use anything other than stock plugs. They work and they were calibrated for our engines.
 

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Added Today:7-10-07
PLUGS are PART OF THE system. You may not notice if the system is working or not as low levels of detonation are not audible, but can and do cause issues over a longer period of time. Additionally, even LOW LEVELS of detonation in high compression engines can lead to "PRE-Ignition " from hot spots caused from this low level of detonation. Pre-ignition is far more damaging than detonation, as that ( pre-ignition ) is mainly the cause of "HOLED PISTONS".

Just a word of caution !!!
And just because SOMEONE else may have used a different PLUG without issues, does not mean it will work for everyone else. Where, and at what operating range of the engine along with the fuel, are just some of the variables that might allow one to work and one NOT TO work correctly. And one failure of the KNOCK system at precisely the wrong time can have very dire results.
Manufacturer's not only test as many variables as possible, when calibrating an engine, but build in a margin of robustness. And one last point about using OTHERS experience as a basis for no BAD RESULTS. Do you think there are NOT changes to both software and calibrations as standards CHANGE from year to year? Those darned engineers need something to do !!!!
Personally, I see no reason to use anything other than stock plugs. They work and they were calibrated for our engines.
Is this a quote from someone at Harley or Delphi ? Very good write-up
 

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First, thank you FatbyRR for posting that information. I have added it to my subscribed threads for safe keeping. I am a sponge for information and you appear to be quite knowledgeable regarding the ION detection system.

Please correct me if I am wrong. I believe you are saying the ION detection system monitors the resistance at the coil and compares it to an established allowable range. The ION system will adjust the timing as required to prevent detonation.

A comparable would be a closed loop system which monitors the AFR based on a mapped range and adjust the fuel to keep it within the desired range.

So what happens when the established range is changed? When the turbo is added the plugs are changed to a cooler plug. The cylinder pressure is also increased when boost is applied but returns back to normal pressures without boost? Can the data provided to the ECM be captured and mapped? Can the parameters be altered by adding or removing resistance in the circuit to offset modifications to the engine?
 

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Red-Rod said:
... Please correct me if I am wrong. I believe you are saying the ION detection system monitors the resistance at the coil and compares it to an established allowable range. The ION system will adjust the timing as required to prevent detonation. ...
The ION sense system doesn't measure the resistance of the coil. This system applies a 400 volt DC bias on the spark plug gap in between spark events via pin "A" on the coil (gray with blue stripe wire). This connects to the spark plug through the coil secondary winding. This bias voltage will ionize the combustion gases and result in an "ion current flow" in this ion sense circuit. The shape of the current flow vs. time in this circuit is analyzed to determine when knock has occurred. In a way it is measuring resistance of the secondary winding but the variable is not the coil but the resistance of the combustion gases. The heart of the system is the circuit within the ECM that determines when knock occurs.
 

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Discussion Starter · #19 ·
Guys I am impressed, seriously impressed. I will keep monitoring the plug situation.

I have to say that these bikes are something else. Currently mine seems to have a mind of its own thinking about spark plug differentiation and still working out how many miles is left in my Ricks Tank!!
 
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