Operating temperature question...
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Tourer
Joined: Apr 2015
Posts: 444
Likes: 92
From: xx
Operating temperature question...
I know this question gets asked once in a while, but all I could find was about older HDs. Since this is my first proper Harley, I just want to have a piece of mind knowing my bike is not doing something crazy. So...
Today was 87F, 68% humidity, and it stopped raining. I just got an iPhone holder in the mail, so what's the first thing I did? Mounted the phone and put it on view sensor data from my FP3. Cruising at steady 70-75MPH, the engine temp stabilized at around 255F. This is with Twin Slash Cut Ovals, K&N filter in stock housing, and autotuned FP3 map.
From what I've read, that seems ok, I just wanted to make sure. I don't think I've ever seen over 240F on my prior liquid-cooled bikes, but that's not a fair comparison.
Today was 87F, 68% humidity, and it stopped raining. I just got an iPhone holder in the mail, so what's the first thing I did? Mounted the phone and put it on view sensor data from my FP3. Cruising at steady 70-75MPH, the engine temp stabilized at around 255F. This is with Twin Slash Cut Ovals, K&N filter in stock housing, and autotuned FP3 map.
From what I've read, that seems ok, I just wanted to make sure. I don't think I've ever seen over 240F on my prior liquid-cooled bikes, but that's not a fair comparison.
I think it may be reading something different... Head Temp maybe.
Mine runs that neighborhoed on HT, but ET stays around 200 +/- a few, up to around 220 in traffic, and that has been true all the way up over 100 ambient down here in San Antone.
Mine runs that neighborhoed on HT, but ET stays around 200 +/- a few, up to around 220 in traffic, and that has been true all the way up over 100 ambient down here in San Antone.
Road Captain
Joined: Mar 2007
Posts: 538
Likes: 15
From: Eastern MA
I know this question gets asked once in a while, but all I could find was about older HDs. Since this is my first proper Harley, I just want to have a piece of mind knowing my bike is not doing something crazy. So...
Today was 87F, 68% humidity, and it stopped raining. I just got an iPhone holder in the mail, so what's the first thing I did? Mounted the phone and put it on view sensor data from my FP3. Cruising at steady 70-75MPH, the engine temp stabilized at around 255F. This is with Twin Slash Cut Ovals, K&N filter in stock housing, and autotuned FP3 map.
From what I've read, that seems ok, I just wanted to make sure. I don't think I've ever seen over 240F on my prior liquid-cooled bikes, but that's not a fair comparison.
Today was 87F, 68% humidity, and it stopped raining. I just got an iPhone holder in the mail, so what's the first thing I did? Mounted the phone and put it on view sensor data from my FP3. Cruising at steady 70-75MPH, the engine temp stabilized at around 255F. This is with Twin Slash Cut Ovals, K&N filter in stock housing, and autotuned FP3 map.
From what I've read, that seems ok, I just wanted to make sure. I don't think I've ever seen over 240F on my prior liquid-cooled bikes, but that's not a fair comparison.
The FP3 is reading the Head Temp
Seasoned HDF Member
Joined: Jan 2006
Posts: 11,463
Likes: 2,990
From: Charleston, SC
You know I saw a screen shot of the FP3 interface the other day. I'm wondering how they are calculating head temp?
There are only a few temp sensors on the Twin Cam. Engine Temp sensor which is actually on the rear of the front head and the air intake temp which is inside the TMAP.
If you have a Twin-Cooled engine there is a coolant temp sensor as well, but there is no dedicated "Head Temp Sensor" anywhere to be found in any system.
Wondering how the FP3 is figuring that...
There are only a few temp sensors on the Twin Cam. Engine Temp sensor which is actually on the rear of the front head and the air intake temp which is inside the TMAP.
If you have a Twin-Cooled engine there is a coolant temp sensor as well, but there is no dedicated "Head Temp Sensor" anywhere to be found in any system.
Wondering how the FP3 is figuring that...
Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
You know I saw a screen shot of the FP3 interface the other day. I'm wondering how they are calculating head temp?
There are only a few temp sensors on the Twin Cam. Engine Temp sensor which is actually on the rear of the front head and the air intake temp which is inside the TMAP.
If you have a Twin-Cooled engine there is a coolant temp sensor as well, but there is no dedicated "Head Temp Sensor" anywhere to be found in any system.
Wondering how the FP3 is figuring that...
There are only a few temp sensors on the Twin Cam. Engine Temp sensor which is actually on the rear of the front head and the air intake temp which is inside the TMAP.
If you have a Twin-Cooled engine there is a coolant temp sensor as well, but there is no dedicated "Head Temp Sensor" anywhere to be found in any system.
Wondering how the FP3 is figuring that...
Road Warrior
Joined: Jul 2013
Posts: 1,624
Likes: 13
From: Fort Worth
You know I saw a screen shot of the FP3 interface the other day. I'm wondering how they are calculating head temp?
There are only a few temp sensors on the Twin Cam. Engine Temp sensor which is actually on the rear of the front head and the air intake temp which is inside the TMAP.
If you have a Twin-Cooled engine there is a coolant temp sensor as well, but there is no dedicated "Head Temp Sensor" anywhere to be found in any system.
Wondering how the FP3 is figuring that...
There are only a few temp sensors on the Twin Cam. Engine Temp sensor which is actually on the rear of the front head and the air intake temp which is inside the TMAP.
If you have a Twin-Cooled engine there is a coolant temp sensor as well, but there is no dedicated "Head Temp Sensor" anywhere to be found in any system.
Wondering how the FP3 is figuring that...
There are several temp related channels within the Delphi ECM. The most common channel used is Engine Temperature which is based directly off the 0-5V signal from the ET sensor on the front cylinder head, this channel is reported on the databus as ET. Generally speaking when we speak of engine temp we refer to the data from this channel, we usually consider 240-320F about the normal range relative to conditions, engine mods, and other variables. The second channel is Head Temperature which this is a bit more complex, it is a model the ECM calculates based on the ET sensor, the intake air temp (IAT) and other factors. Head Temp is used within the ECM primarily for Spark Temp correction, for most combination it will run between 260-400F. Note: Heat Temp has been recently added to the PV channel list an is reported as HeadT. The last channel is Coolant Temp which is active on twin cooled and V Rod applications. Hope this info helps...
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My head temp reads 122° when the bike hasn't ran in days... the rest of the temps, ET, IAT, AAT and CT usually read the same.
I figured it had to be a calculated number.
I figured it had to be a calculated number.
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Seasoned HDF Member
Joined: Jan 2006
Posts: 11,463
Likes: 2,990
From: Charleston, SC
It is not a function of the FP3 as PV has the same channle, the calculations are done by the ECM. Here's a reply I got from Jamie regarding it.
And, here is the entire thread: https://www.hdforums.com/forum/touri...ead-temps.html
And, here is the entire thread: https://www.hdforums.com/forum/touri...ead-temps.html
Thanks!
Last edited by lp; May 10, 2015 at 06:50 AM.