Ok guys new Harley owner here. Ive had it for about 2 months, and 3000 miles, so bear with me.


Why do you have to retune the bike when/if you change something as simple as an air cleaner?

Arent these complex machines, with even more complex technology driving the fuel injection. I mean Ive been working with cars for years, and fuel injection learns itself, and make modifications to itself. So why the tune.

I can understand people wanting to change mapping, Ive done that type of thing with a few of my car builds, but, I only want to change an airfilter, I dont want to spend 3 hrs labor, 450 for the tuner plus an a/c. Doesnt this seem a little bit much?

Yeah yeah yeah I know welcome to the harley club. I fully expected that when buying a harley I would want to spend $ to customize it and make it mine, but its just a damn air cleaner.

Are tunes really required when changing an a/c?

 

I have been told no...if you do an a/c change or an exhaust change only then no tune needed...if you do both then a remap is needed. When I did the Stage 1 on all my bikes I did both so I had to remap and/or tune.

 

You don't. Harley should tell you the O2 sensors once the bike is warm will send a signal to the EMS to adjust. The thing is I've not heard of this working well.
The sponsor of this site is Fuelmoto. Besides offering a really nice air filter, chrome, they also sell piggy back fuel management systems. I have an old power commander. There are a lot of fuel management systems on the market. They can be prest to match any changes and rest as needed.
I have an 07 RK. FM air cleaner and slip-ons, and a PC.
Finding someone who can dyno right is hard. The cat and O2 sensors are EPA mandates that deminish preformance and add heat. By useing a fuel manager you can reset, yourself, as you change exhaust parts.

 

On the bikes with a cat you don't need to retune if you just change the a/c. You can also do slipons and it still runs acceptably. Beyond that and you are outside of the stock ECU's adjustment capability, and it's not optimal.

 

I have removed the cat. But I still cant see why an air cleaner change would cause such a change. Oh well.....

 

The additional air flow may be outside the parameters of the ecu.
( some would think that there is obsolescence built in)

You know what you are doing, and can identify the signs of a lean operating condition.

So, change it. ( and I suggest the Ness big Sucker $115 on ebay from easternpc- get the chrome backing plate version- it has a washable oiled filter media- unlike the screaming eagle and is a tidier install at less cost).---- some guys just take a hole saw to the sides of the plastic plate- you may have to tune out whistles if you do that.
The advantage to the Ness or Screaming Eagle hi flow air cleaners is the air horn which orders the air entering the intake

I have the Ness on my 09, I have stock no cat headers ( so the exhaust crossover can contribute to scavenging) and supertrapp megs tunable mufflers.

In my case, my bike in stock trim slightly pinged under certain conditions, 3000 rpm going up a 6% grade ( which we lots of here in AZ)- that was stock.

Understanding that the bottleneck to flow is more the ac than mufflers on non-cat bikes ( and I believe that the cat is more restrictive than the stock ac housing on current models)
- I put on my mufflers and tuned them to the bike ( ***-dyno)

Pinging was same, as i had expected, but not worse.

I used Nightrider.com XIEDS- basically a resistor network inline with th eO2 sensors, they drop the sensor voltage to the ECM, causing the ECM to increase the pulse width.
- about $125 shipped

Pinging went away all together, plugs are fine, no tailpipe soot and mpg dropped maybe from 44 to 43...maybe.

Changed my ac to the Ness, *** dyno says good, no pinging, retuned mufflers again to match.

This stage 1 is the least expensive power gains to be found on an H-D. expect 7 to 10 HP, perhaps cooler running, the richer mixer can produce a slightly lower exhaust note.

So that's what I did--- $240 + the mufflers I took off my old bike before I sold it--- I've been using that pair of mufflers for over 10 years.

But with your background and ability, I'd suggest you swap AC and see if the ECM keeps up.

ps the stock "football" air cleaner cover does a nice job hiding the sensor wiring on the aft side of the intake, and is also the "budget choice".
The ac's can supply flow in excess of demand so the "ram" air cleaners out there are just a fashion statement ( and get in the way of my boot when braking)

Mike

 

****, I only wish I were getting 43 mpg, Im running about 35 right now.

 

Your first mistake is thinking that the H-D EFI is anywhere near the sophistication of todays automotive EFI systems; not even close. No matter what mods you make, the only adjustment the H-D EFI will make is under no load condtions, i.e., cruise and idle; verywhere else your locked in to a "stoich" AFR of 14.7; great for water cooled V8s but not so much for an air cooled VTwin. These motors come from the factory way lean to meet EPA regs.

Second mistake is opening up the A/C and not the exhaust; a waste of money IMHO. The first upgrade most new H-D owner do is the Stage I, A/C, pipes and some sort of adjustment to the ECM. If you are opening up the A/C open up the exhaust; a set of Cycle Shack, Rush or Fullsac slipons will make a difference. If that is as far as you want to go, get a Dobeck/Techlusion DFO/TFI system. Easy to install, great customer service and you can adjust fuel yourself, no dyno time required. You cannot adjust timing but don't need to at Stage I. Do it all; you will thank me.

Both my bikes are old so I can't intelligently discuss the pros/cons of removing the cat but there two sides to that as well WRT performance benefit.

 

Cat was removed for heat purposes,

Air cleaner, I simply dont like the stock one.

 

Just be aware of those wires I mentioned above--- some riders go to something sleek, then all the crap hidden by the football is exposed.

By then they've already shelled out for the new thing

mike