Investigations from 12-4-2004:
We had a great day of learning, Round Rock Donuts, coffee and Popeye’s Chicken.
Attendees: Duc, Big Al, Bill, Wmoore, Johnnycheese, highnote, and a few other of Johnny’s customers that just like to “hang and learn.” Great to meet you guys. Duc and BigAl, always great to see you.
Background:
The discussions surrounding Cliff Randall’s “enriched” map has been driving a lot of good discussion and some inspired quests for information. Several folks have loaded the map and claim excellent results. However, others remain unconvinced.
Many thanks to Cliff Randall for putting this map together and making it available for testing and to Johnny for helping support my habit of tinkering.
Cliff Randall’s recent post “PC3 Mapping 101” is the latest of the discussions. Here is the link to this recent thread:
http://www.vtxoa.com/forums/viewtopic.php?t=46243&highlight=
I mentioned that I was willing to load Cliff Randall’s map and give my honest opinion and additionally do some WOT pulls with the map loaded to do an apples to apples comparison to my custom map.
Cliff Randall asked me about my configuration and created a map specific to my configuration. I refer to this as “Cliff’s HN Map.”
A few months earlier in August, jimsol1’s post “cliff’s map” was a good conversation that drove additional curiosity from my perspective. Here is the link to the thread:
http://www.vtxoa.com/forums/viewtopic.php?t=32496&start=25
My open curiosity from this thread centered around the A/F ratio transient response to a step-function increase in throttle starting at various points in the range:
1) Is there really a transient A/F
ratio spike when the throttle opened in a step-function
manner?
I had only seen dyno pulls starting at around 1k or 1.5k rpms and there was always a transient lean condition.
2)
What is the amplitude of the A/F ratio spike if the throttle was suddenly opened
1k, 2.5k, 3k RPM
3) How long do these
transients last at 1k, 2.5k, 3k RPMs
4) Is the momentary lean
condition "a good thing?"
5) Am I pi$$ing up a rope?
I had enabled the accelerator pump feature with the settings for “street riding” and had been running it like this for 5 months. I had not yet dynoed with the accelerator pump.
I have an ’02 1800C, Thunder Teardrop intake, V&H Bigshots, Quiet Baffles with ceramic wrap, Bosch 4419 plugs, desmog, Mobile 1 red cap oil, Barrett clutch springs, ground fix.
All tests were performed by Johnny at Johnny Cheese Performance. Pflugerville, TX
Objectives:
Install Cliff’s HN Map and objectively compare the rideability attributes
Compare Cliff Randall’s Map on the Dyno to my custom dual map based on WOT pulls
Tweek my Dual Cylinder map because Johnny learned some new tricks since he did my last map
Conduct some roll-on experiments to characterize the A/F ratio transient response to throttle increases
Test Results:
· Rideability:
The Rideability attributes were tested via an 8 mile ride from my house to Johnny Cheese Performance.
The engine ran rough in the low range RPM, similar to a lugging feeling, however, pulled strong above 3000 RPMs
I did not notice any difference in the shifting.
Strong smell of gas at stop lights and during Dyno runs.
Plugs examined before and after the installation of the map looked identical both times (The plugs indicated a rich condition prior to Cliff’s map being installed.)
· WOT Dyno Pull Comparison (Figure 1) showed the highnote custom map out performed the Cliff’s HN map across the range of RPM.
· Accelerator pump with a static setting 90/15%/20 is way too fat for my bike (with my custom map) and stays rich for much longer than 20 engine revolutions resulting in a power loss (Figure 2).
o Once the Accelerator Pump hits its duration threshold, the A/F ratio goes leaner than if the pump were disabled.
· The accelerator pump enriches an already enriched Cliff’s HN map thus dropping performance even more in the low range. (Figure 3)
o Once again, the remainder of the pull is significantly leaner
· Improvements were achieved by making iterative adjustments to the cylinders (Figure 4)
· Roll-on under load at all engine speeds produced transient lean conditions (Figure 5)
· The bike and dyno is fairly consistent. The final run from 1 year ago is close to the map we did today. (Figure 6)
Conclusions:
· Cliff’s “modified for highnote” map is extremely fat (for this bike) which resulted in a loss of HP and Torque, however, above roughly 3200 RPM I could not detect this power loss and the dyno shows this loss to be nominal.
· The Seat of the Pants performance loss in the low range of Cliff’s HN map could be due, in part, to the accelerator pump enriching an already enriched motor.
· A flat A/F ratio is not the objective (Fatter is better down low on this motor… to a point)
· If the accelerator pump is to be used, it should be used to optimize the A/F ratio transient response to the throttle step-function, but not to the point where performance is lost due to the mixture being too rich. (Dyno is recommended)
· The two “typical” settings in the accelerator pump installation manual result in a mixture that is way too fat for my bike
· A map should be created after the accelerator pump settings are chosen when the feature is enabled
· The black condition of the plugs (indicating a rich condition) were most likely caused by the settings of the accelerator pump feature.
· There was more optimizing to do on the highnote custom dual map, but we ran out of time. Plan to schedule time in 2 weeks.
· Johnny is awesome and professional. He is a pro, but he approaches his work like it is a hobby!
Open Questions:
· Why is the A/F ratio leaner in the upper range if the accelerator pump is enabled?
· The Accelerator pump is only supposed to squirt extra fuel for 20 engine revolutions, however, the enriched condition lasts for a much longer time. What is the cause of this lengthened enrichment.
· Why is tuning dual cylinders an iterative process
o Why does the A/F ratio of cylinder 1 change after a change in cylinder 2’s map?
Next Steps:
· Check the plugs for color to see if rich condition is now gone
· Make some minor adjustments to the Dual map at 2750, 3200-3500 (See figure 4)
· Install Accelerator Pump, but turn the knobs way down and repeat Roll-on Tests to optimize for roll-on response.
· Remap with validated (via dyno) accelerator pump settings
· Try Al’s Headlight test.
· Publish results
All four plugs were dark which indicates a rich condition. They were this way before Cliff’s HN map was installed. Later, we found out the accelerator pump richens things pretty good. Very likely, the culprit. See below.
Photo 1: Johnny holds a nasty looking plug
Figure 1: Cliff’s HN map vs. highnote final dual map
Cliff’s map made for highnote (Cliff’s HN Map) compared against highnote’s custom map.
Test environment:
The highnote custom map produces higher horsepower and torque across the entire range of the run.
The highnote custom map produces a leaner A/F mixture across the entire range of the run.
Figure 2: highnote custom map with and without accel pump
Dynorun.027 – Accelerator Pump Disabled
Dynorun.012 – Accelerator Pump Enabled
When I installed the accelerator pump option from Dynojet, I referenced the FAQ in the Installation instructions. This is what is printed:
Some Racers have selected the following:
75% Sensitivity
20% Fuel Increase
15 Engine Revolutions
Some Street Riders have selected:
90% Sensitivity
15% Fuel Increase
20 Engine Revolutions
I chose to enter the “Street Rider” version. According to the instructions, after 20 engine revolutions the Accelerator Pump disengages.
The chart shows an “enrichened fuel state” from approximately 1750 RPMs to 2750 RPMs.
The settings I used with the Accelerator pump feature were clearly not optimized and the result was a loss of power immediately after the throttle is cracked.
Notice the subsequent “leaner” state after the accelerator pump disengages after 3000 RPM
Open Questions:
Is the Accel Pump increasing the fuel for this long or is there another influence?
Figure 3: Cliff’s HN Map with and without accel pump
Cliff’s HN Map with and without the accelerator pump feature enabled.
Dynorun.003 – Accelerator Pump Enabled
Dynorun.020 – Accelerator Pump Disabled
Dynorun.023 – Accelerator Pump Disabled
All three pulls go off the richness scale (limit = 10:1 A/F ratio). This map is extremely FAT for this bike throughout the RPM range, but particularly between 2k and 3k RPMs.
Things to note:
Non-conclusive Theory: The ECU is responsible for the leaner condition due to it is not sensing as much load. There is more thinking to be done here.
Rideability observations:
This was mentioned to Johnny upon arrival and before any Dyno runs were made: “The low-end of the bike is quite sluggish. It feels like it is lugging up to about 3000 RPMs. However, from about 3000 RPMs upward, I did not notice any decrease in performance from my map”
Question: if the Accelerator Pump were disabled the upper range would presumably be richer. Would the drop in performance shown in the chart then be detectable via SOP (Seat of the Pants)?
Figure 4: highnote base map and dual map comparison
Dynorun.017 was when Johnny finished the front cylinder and just before he started on the rear cylinder. The O2 sniffer is on the front jug. Dynorun.027 is the final dual map pull for the day. The O2 sniffer is on the rear jug.
Note: The map was a dual map to begin with, so the modifications to the rear jug was only minor.
Johnny went back to the front again because he learned the results are iterative.
Questions: Why is the tuning iterative? Could the crossover be affecting the other cylinder’s A/F ratio that much? Does the ECU detect a load change and compensate?
Figure 5: Roll-on Tests compared with Dynorun 27
For this test, the bike is stabilized at the target cruising RPM in 4th gear under a nominal load. They dyno sample is started and the throttle is cracked to WOT. The objective is to characterize the A/F ratio after the throttle is cracked.
Dynorun.3250 – Roll-on starting at 3250 RPM
Dynorun.2750 – Roll-on starting at 2750 RPM
Dynorun.2250 – Roll-on starting at 2250 RPM
Dynorun.027 – Same old final run with dual maps
The transient lean condition is confirmed immediately following the cracking of the throttle. I believe the Accelerator pump feature can flatten this out. However, as seen before, a leaner condition will occur after the accelerator pump cuts out. For this reason, the accelerator pump must be set up first, then the map.
Figure 6: highnote map - November 2003 and December 2004
This shows the final highnote dual map from this experiment compared to a single map from 1 year ago, under roughly the same air quality conditions:
Dynorun.027 – Final WOT run of this experiment
Dynorun.013 – Final WOT run 1 year ago
Not much change except perhaps optimization due to dual maps and a map more optimized at the low-end.
