I'm more confused now. I have attached a log that I ran with my PV. I have the LJ fans on my bike. While I was sitting at traffic light, my HT dropped from 340 degrees to 329 degrees. My ET didn't move at all. It stayed at 253 degrees. I'm guessing that my HT dropped because the fans blow directly through the head channel and on the sensor. If the temp sensor is a ET "hard reading" as you indicate, how come my my ET didn't decrease.

 

I don't buy it.. The head and engine temps of PV are the same head and engine temps for TTS and the HD tuners. Why? When you get right down to it. The aftermarket tuners are nothing more than an interface to modify the ECM (IIRC Cole adds some code).. Core ECM code that the unit runs is the same across all flash tuners. Why change naming / function? The flash tuners still rely the core code to run the motor. The algorithms are pretty sophisticated.

If you look at Tmax, they call the temp sensor in the head, head temp but then they are a complete replacement ECU. Nothing is from Delphi.. This is probably the main reason why I found out it was different. 2 Temp on the Delphi system where Tmax only uses 1.

CHT temps will change first because they are calculated.

The LJ fans are not being given enough time. Really need to see more time..Still the engine temp may not do anything. Switch the fans off. Chamber temps will change faster than engine temps. It's where the source of the heat is coming from. Stall /stop the motor with and without the fans and log the temps. You'll find some interesting things.

 

BTW This is a good thing.. I've thermocoupled up big carbed motors. Roll too a stop and temps jump up..

 

Your HT (which is not a hard number, but an algorithm derived number) dropped because you were stopped, no longer putting a load on the engine. Even without the fans, that HT number will drop when you come to a stop.

If you are stopped long enough, it is likely the HT number will get very close to the ET number.

Your ET did not drop when you stopped because the actual temperature of the left rear part of the front cylinder head (where the sensor is located) did not drop. If you did not have your fans on, likely it would have increased.

As I noted in my previous post, the HT number varies quite a bit, based on a variety of factors...ET and load on the engine are two of the biggest. So as you are riding, especially if you are accelerating, that number will move quite a bit, and quite quickly.

The ET number is much more stable and slowly moves up and down as the actual temp of the part of the cylinder head where the sensor is located changes.

One thing you can do to get a better feel for how it works-

Have the display of the PV set to show the ET
Start the engine and let it set (fans off) and watch the ET go up
(Don't let it go over 260*)
Around 240* turn the fans on.
You will either see the temp start dropping a little, or at least slow down in how fast the temp is rising.

 

I'll give that a try.

One more question/comment. My oil temps generally run 220 - 240. At the same time I am seeing ET on my PV at 230 - 260 and HT on my PV at 320 -330. Are you saying that the actual temperature of the sending unit screwed into the front head is what is being reported as ET on the PV? How can that sending unit's temperature be the same or similar to the oil temperature that I'm seeing? I would think it would be much hotter since it is screwed into the hottest part of the engine?

I would think the temperature of the head sending unit would be the actual HT and the PV would report such as HT. Then the ECM does whatever it does with "load and algorithms and what not" to report a calculated ET. I cannot believe my oil temperature measured in the oil pan is the same or very close to the sending unit temperature in the head. What do you think?

 

Why would the HT's change first because they are calculated? Wouldn't whatever the HT's were calculated from change as well?

I don't understand why the HT's dropped 10 degrees and the ET's didn't move at all. If the HT's are calculated, they are calculated from something right. DK indicated that they are calculated from the ET. So how did the HT's drop when the ET's stayed the same?

 

CHT is directly from the sensor, I dont think it's calculated from anything.

CHT went down because your fan blew on it. Your ET didnt go down because it was supposed to go up after you stopped, so all the fan did was preventing it from going higher.

Did u try to wait for a longer period of time and see if it drops or not?

 

That is kinda what I thought, but DK said otherwise. I was just seeking some clarification/thoughts from him.

 

One thing to note is that the sensor is not screwed into the hottest part of the motor.. YOU can see a 20 to 40 degree spread between the intake side and exhaust side of the motor.. Try and IR heat gun sometime.

ET is the heat temp sensor.. They can track within 0 -20 easy. Some of it depends on the lifter flow to the heads..

 

Show more of the table.. What were you doing before? If you just started the bike I would expect them to go up but since they are going down, I would assume that you had just come to a stop. They are calculated from engine temp + load like in the table I showed.