Want to know your ICE RPM's?

MrFixit

MrFixit

Well-Known Member
There gas been a great deal of discussion about the RPM's of the ICE. The context of this has revolved around the Angry Bees, but also at other times when the engine is running with no apparent rhyme or reason. Some have gone so far as to quote numbers (ie: sounds like 5,000 RPM's) when the reality is that nobody's ear is calibrated enough to really render a useful quantitative measurement.

Today, I decided to attempt to answer this burning question. I connected an OBD2 scanner to the car, and set out on a ~30 minute journey. I chose this trip specifically such that I was in EV mode for approximately 1/2 of the trip, at which point I knew the EV miles would reach zero, and I would be on gas for the remainder. To my delight, the OBD2 port does report the RPM's of the ICE. It is of course zero when you are entirely electric. When you transition to 'hybrid' mode, then the ICE continually cycles on and off depending on the terrain and your demand.

Here is a graph that shows the vehicle speed and the ICE RPM's throughout this 30 minute trip:

upload_2019-1-4_17-12-4.webp
Note that at around 950 seconds, the EV miles reached zero, and the ICE began to operate. It ran at a steady 1500 RPM's, and then up to 1800 or-so for another stretch. We stopped for a few minutes (to get gas), and started up again at around 1200 seconds.

In order to see the detail a little better, here is a plot that zooms in from 1200 to 1500 seconds:

upload_2019-1-4_17-16-57.webp
The ICE seems to 'like' running at ~2000 RPM's with some variation between 1200 and 2300. I did try briefly going into HV-Charge mode (the last spike on the blue curve on Plot 1. HV-Charge just seemed to run at a very steady 2000 RPM.

As expected, the engine RPM's do not correlate to the vehicle speed (ie: not the normal transmission behavior since the engine is charging rather than driving the wheels).

Note - This my first look at this. It was for one convenient trip. I am sure there can be a lot of variation depending on the driving scenario.

What would be of great interest is the behavior with the Angry Bees! I have not experienced the Angry Bees (and I am not sure that I want to)... However, if someone can tell me precisely how to summon the Bees, I may be willing to log a test run in order to put to bed the discussion of what the Bee RPM's actually run.

BTW - it is 'easy' to set up to log your RPM's. I used a $10 OBD2 device that communicates with a smart phone via BlueTooth. I used the 'Torque' App which is capable of generating log files, which can be downloaded as a .csv file and plotted with your favorite spreadsheet tool. If someone actually wants to try this, I can provide more details.

Although the RPM's are available, I did not find much else that seemed useful. I would love to somehow access the wealth of engineering data that probably exists somewhere, but Honda will never be willing to release details of a diagnostic API (or similar).
 

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MrFixit said:
There gas been a great deal of discussion about the RPM's of the ICE. The context of this has revolved around the Angry Bees, but also at other times when the engine is running with no apparent rhyme or reason. Some have gone so far as to quote numbers (ie: sounds like 5,000 RPM's) when the reality is that nobody's ear is calibrated enough to really render a useful quantitative measurement.

Today, I decided to attempt to answer this burning question. I connected an OBD2 scanner to the car, and set out on a ~30 minute journey. I chose this trip specifically such that I was in EV mode for approximately 1/2 of the trip, at which point I knew the EV miles would reach zero, and I would be on gas for the remainder. To my delight, the OBD2 port does report the RPM's of the ICE. It is of course zero when you are entirely electric. When you transition to 'hybrid' mode, then the ICE continually cycles on and off depending on the terrain and your demand.

Here is a graph that shows the vehicle speed and the ICE RPM's throughout this 30 minute trip:

View attachment 3266
Note that at around 950 seconds, the EV miles reached zero, and the ICE began to operate. It ran at a steady 1500 RPM's, and then up to 1800 or-so for another stretch. We stopped for a few minutes (to get gas), and started up again at around 1200 seconds.

In order to see the detail a little better, here is a plot that zooms in from 1200 to 1500 seconds:

View attachment 3268
The ICE seems to 'like' running at ~2000 RPM's with some variation between 1200 and 2300. I did try briefly going into HV-Charge mode (the last spike on the blue curve on Plot 1. HV-Charge just seemed to run at a very steady 2000 RPM.

As expected, the engine RPM's do not correlate to the vehicle speed (ie: not the normal transmission behavior since the engine is charging rather than driving the wheels).

Note - This my first look at this. It was for one convenient trip. I am sure there can be a lot of variation depending on the driving scenario.

What would be of great interest is the behavior with the Angry Bees! I have not experienced the Angry Bees (and I am not sure that I want to)... However, if someone can tell me precisely how to summon the Bees, I may be willing to log a test run in order to put to bed the discussion of what the Bee RPM's actually run.

BTW - it is 'easy' to set up to log your RPM's. I used a $10 OBD2 device that communicates with a smart phone via BlueTooth. I used the 'Torque' App which is capable of generating log files, which can be downloaded as a .csv file and plotted with your favorite spreadsheet tool. If someone actually wants to try this, I can provide more details.

Although the RPM's are available, I did not find much else that seemed useful. I would love to somehow access the wealth of engineering data that probably exists somewhere, but Honda will never be willing to release details of a diagnostic API (or similar).
Click to expand...

Wow, this is great. I can’t help with advice on how to summon the Bees, but I’d love your detail on which OBD2 device you are using. This looks like fun.


Sent from my iPhone using Inside EVs
 
I don't want to appear to openly endorse a product here (may be frowned upon),
but I will send a PM indicting which device I used to interested individuals (jorgie393 - I will PM you).
 
I'm interested as well. Let me know if there are any EV battery or other parameters provided.
 
Ray B said:
I'm interested as well. Let me know if there are any EV battery or other parameters provided.
Click to expand...

There is a list of parameters within 'Torque" that I believe are 'generic'. These all look like parameters that apply to a conventional vehicle however. The only one that I saw that was active (and seemed interesting) was this engine RPM. As such, I saw nothing that was more specific to an EV. I would love to see quantitative battery drain / charge rates or similar. Having said that, 'Torque' allows you to define custom PID's. I have a strong suspicion that there are some EV parameters available through the OBD2 interface, but you would need specific technical information in order to define and therefore view them. I think I remember seeing in another forum, that someone had PID definitions for an Accord Hybrid which included some EV parameters. There may be some overlap with the Clarity. I think it would be extremely difficult to reverse-engineer other parametric data, and it is unlikely that Honda will willingly provide technical details.
 
JCEV said:
Try some agressive driving from stop to stop to get angry bees. Very interesting !
Click to expand...

I don't think I could bring myself to "drive aggressively stop to stop" in the hope that the Bees might swarm...
Maybe there is some procedure that is a little more specific that someone has found?
 
Thanks for the data and the charts. The charts show exactly why it is currently impossible to compute an mpg with this car. You can get a macro view of gallons used over a given distance but the truth is the car switches often between EV / Regen / ICE running and that creates a mix. The battery is charged by the ICE, being plugged into AC, and through regen. Further as you indicated the ICE isn't connected to the wheels in your chart; its generating electricity. Even if I could record miles traveled only while the ICE was actually running I'm not sure what good that data would be.

Sorry I've only had angry bees once and the circumstances made no sense. I was driving down highway 5 in California. The car had been in HV mode for hundreds of miles without us being able to hear the engine at all. The battery had at least 1/2 charge. There was a slight elevation increase (almost unnoticeable) and suddenly the angry bees appeared. The sound continued for less than 5 minutes. At that point we began the steep climb up into the mountains (on a road usually referred to as the grapevine) when the angry bees went away and just high revolutions could be heard working hard to carry us up the hill.
 
What would be obstacles/difficulty/cost associated with setting up a real time RPM digital display and ideally also average RPM during a run from start to stop?
 
The State of Charge (SOC) of the traction (main high voltage) battery is available from the OBD2 data. The engine coolant temperature takes a custom PID setup as Honda does not use the normal data output for ECT. The throttle position sensor output is also available (this is not the "gas" pedal position but the throttle plate in the air intake). There are others that one can see in the Torque app list when one wants a custom output screen (add a gauge feature) and there are some other Honda unique PID's which can be found on other Honda (Civic mostly) websites. I have not yet carefully looked at the data list that Torque provides to see exactly what each output data channel provides. I suspect, since the Scan Gauge tool can show data such as the maximum battery amps (condition of the traction battery) that there are other Clarity (or other Honda Hybrid) specific data outputs available if one knows the PID's and output data format.

LeoP
 
Thanks -
It would be interesting to be able to interface it with AA to get a gauge cluster like this...
 
Robert_Alabama said:
What would be obstacles/difficulty/cost associated with setting up a real time RPM digital display and ideally also average RPM during a run from start to stop?
Click to expand...
That is essentially what I had... It wasn't just logged data, I was watching this real-time (on an Android tablet) - my wife was driving... Nothing special required except an OBD2 dongle and an android tablet or smart phone.
 
leop said:
The State of Charge (SOC) of the traction (main high voltage) battery is available from the OBD2 data. The engine coolant temperature takes a custom PID setup as Honda does not use the normal data output for ECT. The throttle position sensor output is also available (this is not the "gas" pedal position but the throttle plate in the air intake).
Click to expand...

Yes, there was an engine coolant temperature (non-operational), and a Throttle Position (operational). I did not see anything related to the traction battery (SOC or otherwise). Perhaps a custom PID setup for a similar Honda would have helped. My 'Torque' only had two canned 'custom' options, neither of which resemble a Honda. Perhaps I need the Pro version... I am using the free "Lite" one at the moment.
 
MrFixit said:
I don't want to appear to openly endorse a product here (may be frowned upon),
Click to expand...
Don't hesitate for a minute to mention specific products that work. It's super useful information that makes forums valuable! Give all us data junkies the hardware info ;)

@AnthonyW was doing some beta-testing for Scangauge, but I'm not sure where that is now.
 
One must add the custom PID's by oneself. They are not in the Torque lite or Torque apps. I do not know if the Torque lite allows custom PID's as I bought the full app for $5 since the app is so useful. The SOC is shown in the Torque app list of available and operational data for my setup. The ECT is a custom PID as Honda does not output that data on the normal channel (PID).

It would be nice to have the Torque app work on the center display. I have yet to try this with my Bluetooth communicating ELM327. My understanding is that non-phone Bluetooth communication with Honda civics 2018 and later is blocked so this might not work for Clarity's.

LeoP
 
Dustin said:
Angry bees should swarm if you accelerate up a long hill with a dead battery in hv charge.
Click to expand...

Atkinson said:
You beat me to it.
Click to expand...

Things are pretty flat around here... I can probably find a hill that lasts for maybe a mile. Not sure if that would be adequate.

A couple of questions -
  • You specifically state a long hill in HV-Charge. This is a catch-22 in the sense that HV-Charge will soon produce [some charge] in the battery, and it will no longer be "dead". Are you suggesting that HV-Charge will bring the bees better than HV because the engine is already running steadily and it is the additional demand that brings the bees?
  • By "dead", do you mean an EV range of zero (2 bars), or should it be worse than that? Theoretically, the vehicle will never let the charge go below 2 bars. I suppose I can force that condition by sitting at the bottom of the hill with the heater running for a while... I don't want to feel like I am somehow abusing my car !
 
I think just keep it in regular HV that will simulate a low battery. I found if I had a location with lots of stop signs or red lights I could easily get the car to rev high. Find a slight hill and the car will temporarily rev very high to generate charge. Also try to limit your Regen when stopping which would mean applying the break a little more agressive vs coasting. Alternatively you could find a hwy ramp and in HV boot it to the speed limit .
 
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