Hondata

Howdy gents,

Is there a way to modify the idle speed inside FlashPro Manager to remove the differential between the <5 MPH idle speed and >5 MPH idle speed? Specifically I'm looking to reduce the moving idle speed down to the same 850 RPM that the engine idles at below 5 MPH.

Special thanks for adding the ability to remove the ignition advance during startup as well as helping us out (via 8thcivic) regarding eliminating the cold start rev hang/erratic idle issue that was coming from the air being introduced through the injectors. Cold drivability has improved unbelievably!

Thanks,

Dave

Possibly. It is not just a simple table like the earlier generation Honda ECUs use.

Maybe you can give me some ideas as to why I'm burning more fuel at idle over stock.

Mods that didn't change and are:

AEM "V2" CAI
P2R Throttle Body Spacer
Intake Manifold Gasket
Vibrant Header w/HFC
Vibrant Street Power Exhaust (2.5")

Only thing that changed:

I went back to eliminating the throttle body coolant
FlashPro MAP tune with Daniel Butler at CAT

Fuel flow as per my ScanGaugeII was ~.19-.22 GPH @ 850 RPM and ~.25-.28 GPH at the moving idle of 950 RPM.

Fuel flow now is ~.30 GPH @ 850 RPM and ~.37 @ 950 RPM.

Fuel flows while under load seem to be in line with what I was seeing before FlashPro.

The scangauge does not measure fuel consumption using injector duration, and I have not found it to be accurate.

A better test would be to datalog the injector duration with the display window control set to average the value over 10 seconds or more. Change the calibration, and then see if that affects the duration. If so, start looking at closed loop operation.

Do you know offhand what the ScanGauge is using to calculate fuel flow?

Anyway, as you mentioned, datalogging the two would be a surefire way to spot any differences. What calibration should I try using to closest resemble my Hondata Reflash state of tune?

While I can't verify whether the scangauge is accurate at all loads and all RPMs, I can say that I get remarkably consistent results using it in both my '05 CR-V and my Si to the point that there is usually less than 1/10 of a gallon difference between the pump and what the scangauge reads when filling at the same pump and regardless of whether all of my driving has been city, highway or a mix of both.

Thanks for letting me pick your brain.

-Dave

The ScanGuage uses air flow, with an assumed air fuel ratio.

Hondata wrote:The ScanGuage uses air flow, with an assumed air fuel ratio.

That's kind of what I was guessing, especially after the load feature (LOD) dropped as a useful feature once I switched to a MAP tune. I now use the MAP reading in kPa to give me an idea how I'm loading the engine, especially since it matches up with the columns in FP Manager.

Should I be flashing back to stock for my comparison?

Alright, I datalogged a trip to and from starting with my tuned calibration (which has been running for about a week so idle is stable) and then reflashed with the 2007+ return to stock calibration. I came up with the following details with my tuned calibration on the left and the stock calibration on the right.


850 750 RPM
190F 194F ECT
78F 78F IAT
1.84 1.9X Inj ms
14.6 14.6 AFR
14.4 14.4 VDC Batt
-8 -9 S. Trim
0 -8 L. Trim

I'm not experienced in this but my guess is that I multiply the injector duration (minus latency) by frequency (RPM) to get an idea of fuel flow on a relative basis. In this case there’s not much difference between the two durations (~5%) but there is a difference in frequency of 100 RPM (13%) and that could be making a difference.

Is there any reason why I can’t move the idle speed down from 850 RPM to the stock 750? Also, is there something I need to do about the short-term trim hovering about -8% at idle and under steady cruise?

Thanks,

Dave

I tried lowering the idle speed to 750 RPM in the 149/176/194 cells and datalogged on the 5 mile drive home. The engine is still idling around 850 RPM. Any ideas why?

The minimum idle speed for the AFM calibration is 750 rpm, and the race calibration is 850 rpm.

Thanks for clearing that up. Why does the idle need to be so high for the MAP calibrations? My '05 CR-V uses speed/density and idles at 650 RPM.

OrdnanceMarine wrote:Thanks for clearing that up. Why does the idle need to be so high for the MAP calibrations? My '05 CR-V uses speed/density and idles at 650 RPM.

I believe the optimal idle speed for the K20 is 830 rpm or so.

VitViper wrote:

OrdnanceMarine wrote:Thanks for clearing that up. Why does the idle need to be so high for the MAP calibrations? My '05 CR-V uses speed/density and idles at 650 RPM.

I believe the optimal idle speed for the K20 is 830 rpm or so.

Why would the Hondata AFM tunes and Honda's stock program be set to 750 then? I can understand why it's different than my CR-V's K24 because the head and intake manifold are completely different but why the difference between AFM and SD on the K20Z3? At any rate, it would be great Hondata made it available for tuning in FP Manager.

Thanks,

Dave

OrdnanceMarine wrote:Alright, I datalogged a trip to and from starting with my tuned calibration (which has been running for about a week so idle is stable) and then reflashed with the 2007+ return to stock calibration. I came up with the following details with my tuned calibration on the left and the stock calibration on the right.


850 750 RPM
190F 194F ECT
78F 78F IAT
1.84 1.9X Inj ms
14.6 14.6 AFR
14.4 14.4 VDC Batt
-8 -9 S. Trim
0 -8 L. Trim

I'm not experienced in this but my guess is that I multiply the injector duration (minus latency) by frequency (RPM) to get an idea of fuel flow on a relative basis. In this case there’s not much difference between the two durations (~5%) but there is a difference in frequency of 100 RPM (13%) and that could be making a difference.

Is there any reason why I can’t move the idle speed down from 850 RPM to the stock 750? Also, is there something I need to do about the short-term trim hovering about -8% at idle and under steady cruise?

Thanks,

Dave

Why don't you tune your part throtle? your Sfuel trim is not very good.

nunoctr wrote:[Why don't you tune your part throtle? your Sfuel trim is not very good.

Already done. I hadn't done it since I was tuned on the dyno last month. I'm seeing 1-2% at idle.