Currently running the Sportster Stage 1 air cleaner setup using the stock air box cover. Always liked the ham can air cleaner cover as it is iconic to the Sportster but, I've decided to go with different look.

I have a Screaming Eagle Chisel Extreme air cleaner coming. The bike has been flashed and autotuned for a high flow air cleaner and the Cobra pipe/muffler, is any setup considered a Stage 1 the same tuning wise? Or would it be smart to run another autotune session when I install the new air cleaner?

 

Put it on and run the bike. You will know fairly quickly if you need to retune.

 

Almost without exception, your engine is capable of only a certain maximum amount of air flow regardless of air cleaner. Yes, I know, most "high flow" cleaner manufactures want you to believe their product can magically increase air flow by some significant amount. The truth is, they almost never can. Air flow is bound by certain physics and without substantial changes downstream of the air cleaner, very little will be gained or lost by simply changing out an air cleaner.

Just talk to most any lawn mower repair shop and they'll tell you horror stories of customers coming in with almost completely clogged air cleaners and the crazy mower still runs...maybe not great but it still runs. A new filter will usually allow the mower to run much better but it will not magically double or triple the engine's hp output.

 

My experience with an M8 Softail may be different than a Sporty, but for what it's worth.... I used the FP3 to load one of V&H's standard Stage 1 tunes and when it came to specifying air cleaner, it was just a "yes" or "no" on whether the user had replaced the stock air cleaner with a high-flow cleaner. I think Pine Tree said it well.

 

I really can't see the smaller round air filter in the new air cleaner flowing any more air than the filter setup that is already on the bike, as it is an exposed oval K&N filter sitting behind the stock ham can cover. I kind of figured a high flow air cleaner is a high flow air cleaner... Was just curious if I was missing something.

I haven't decided if I want to route the breathers out of the new filter like I've done to the existing one. The Chisel Extreme backplate is available by itself for all other models except the Sportster, If I were to screw it up somehow I would have no way to replace it other than to buy another whole air cleaner assembly. I would prefer them routed out of the air cleaner but, there are tens of thousands if not hundreds of thousands of Harley Davidson motorcycles running around that are left as they came from the factory having no issues. Decision, decisions.

 

Something simple first, wind speed.
If you are heading North at 70 mph with a 10 mph North wind you effectively have 80 mph of cooling air flow over the engine.

Heading south you have 60 mph of air flow cooling.
(east or West wind would effect cooling from the right or left side slightly, Air filter size/area)

If you have a SET AFR of 13.5 at 4000 RPMs the ECU will be in open loop and not adjusting the Injector duration based on the O2 sensor volts. Hopefully your VE values are perfect


The 2014+ XL tunes have a Closed Loop Lambda Range for Closed loop operation.
The 2014 DJ Stock Improved tune has this at Lambda 1.023 - 0.964 (AFR 15.0 - 14.2)

A couple of things you might look at, O2 Volts and Fuel Trims.
What are your O2 Volt F/R readings at 4000 rpms at your 70 MPH?
13.5 should be around 0.844 volts (you may only see voltages in +-0.02 volts ranges)
13.4 ~ 0.850
13.3 ~ 0.855
13.2 ~ 0.862
13.0 ~ 0.870
12.8 ~ 0.880
12.5 ~ 0.891

(The O2 volts will vary some, maybe +- 0.040 volts)

(To calculate the O2 volts average to 3 decimal places would require the ability to log sensor data like the PowerVision does)

The ecu will also extend the Long Term Fuel trim (AFF, Adaptive Fuel Factor) from your closed loop operation
range to the Open Loop, Higher MAP ranges of the tune.
(based on the rpm and lower MAP ranges)
(the short term adaptation is not extended out to higher MAP regions, you should see a CLI F/R (Closed Loop Integrator) of 100 in open loop)

Can you monitor the Adaptive Fuel Factor (AFF) for the the front and rear cylinder with the FP3?
An AFF of over 100 is adding fuel, under 100 is subtracting fuel based on your tunes VE table RPM/MAP.

Differences in weather can effect AFR.
The HD ECU can adjust for differences in Air Pressure.
Your MAP will change due to Air Pressure. (may also change your ignition timing MAP/RPM)
It also can adjust for differences in Intake air Temperature, Both VE and Ignition timing.
The VE change will be reflected in the CLI Short Term fuel trims in closed Loop.
The Ignition timing has a Spark Advance By Air Temp table in the tune.

 

I can see compared to me you have a PhD while I haven't even entered preschool. I do appreciate the input.

I hooked up the FP3 and rode the bike about 20 miles west, turned around and rode the same 20 miles the other direction. I saw the head temps drop around 30*F compared to the SE Stage 1 air cleaner setup that had been on the bike. A/F ratio at 70 mph and 4,000 rpm was at 13.2-13.5. As I said in the other thread I started about this temp drop, I am somewhat convinced the ham can air cleaner cover was blocking airflow to the rear cylinder as I have no other idea what else could cause such a drop as I changed nothing else other than the air cleaner, and I would have a hard time believing it could be more restrictive than the one I replaced it with..

Before installing the new air cleaner I was seeing head temps in the 380-390*F range, and had seen them on several occasions. Changing nothing but the air cleaner those temps dropped to the 350-360*F range, and that was in ambient temps of 90*F, same as I was seeing temps in the 380-390*F before.

Bike runs great, head temps down, oil temps are still good (200-210*F range), plugs look good, so I'm happy.