Does a heavy breather air filter effect fuel consumption? - Harley Davidson Forums: Harley Davidson Motorcycle Forum
 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 06-24-2013, 06:54 AM Thread Starter
Junior Member
 
Join Date: Jun 2013
Location: South Africa
Posts: 1
Does a heavy breather air filter effect fuel consumption?

Hi there all

I have a 2013 Fat Bob and recently replaced the original air filter with a screaming eagle heavy breather, Is it my imagination or is my fuel consumption now worse than ever?

Do you have to tune the bike after replacing the filter?

Thanks

Wynand
wynandroos is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 06-24-2013, 07:29 AM
Member
 
Join Date: Jun 2013
Location: Raleigh NC
Posts: 37
Normally you do the breather coupled with an exhaust and a tune...the breather and exhaust drastically affect your air/fuel mixture so you end up getting a new tune programmed for your particular exhaust/breather.
RedRider0151 is offline  
post #3 of 9 (permalink) Old 06-24-2013, 07:45 AM
Senior Member
 
chasarms's Avatar
 
Join Date: Sep 2011
Location: Bettendorf, IA
Posts: 5,627
Images: 2
Garage
Your bike has O2 sensors. Those sensors control the air/fuel mixture. Since you are taking more air in, the bike needs more fuel to match. So, yes, you are probably burning more fuel.

I am surprised it is that significant though. With everything else being stock, I wouldn't have guessed to be more than a 5-10% difference.

Were you expecting it to improve fuel economy?

2011 Ultra Classic Electra Glide FLHTCU
Jackpot 4" Dyno Tuned Mufflers | Jackpot 2/1/2 SPC Head Pipe | Cobra Fi2000 PowrPro
chasarms is online now  
post #4 of 9 (permalink) Old 06-24-2013, 08:47 AM
Mississippi Cajun
 
kd5cqt's Avatar
 
Join Date: Dec 2006
Location: Ocean Springs,Mississippi
Posts: 10,973
Quote:
Originally Posted by chasarms View Post
Your bike has O2 sensors. Those sensors control the air/fuel mixture. Since you are taking more air in, the bike needs more fuel to match. So, yes, you are probably burning more fuel.

I am surprised it is that significant though. With everything else being stock, I wouldn't have guessed to be more than a 5-10% difference.

Were you expecting it to improve fuel economy?
OK, while I totally agree with the O2 sensor, fuel/air mix thingee that you just stated, I have one here that sort of contradicts: my fuel mileage started to really suck last few trips. I had a very dirty stage 1 air filter that I couldn't soak clean and ordered a new one....which I had to wait for since they were out of stock. Got some of the HD de-greaser/cleaner and hosed the filter (got all sorts of funk out of it). Next tank of gas, mileage was up 3mpg. Next one was up 4. More air, better economy would SEEM to contradict the mixture idea. Better breathing, more efficiency?

USAF Veteran, PGR Member, Retired Old Fart! 2011 Electraglide Ultra Classic
kd5cqt is online now  
post #5 of 9 (permalink) Old 06-24-2013, 09:10 AM
2014 FLHXS
 
Wrgiacona's Avatar
 
Join Date: Oct 2011
Location: El Dorado AR
Posts: 2,604
Garage
I just added a heavy breather and Stage 1 flash last week and I'm think I'm seeing worst mileage. But I'm not going to blame the bike. It seems to breath so much easier than it did before that I'm running much higher RPMS and staying in gears lower gears longer for the performance increase.

On my little 25 mile highway run to my favorite weekend watering hole I noticed that I'm staying in 5th on the highway where I used to be in 6th.

I assume the new will wear off at some point and I'll get back into using the higher gears.
Wrgiacona is online now  
post #6 of 9 (permalink) Old 06-24-2013, 09:19 AM
Senior Member
 
chasarms's Avatar
 
Join Date: Sep 2011
Location: Bettendorf, IA
Posts: 5,627
Images: 2
Garage
Quote:
Originally Posted by kd5cqt View Post
OK, while I totally agree with the O2 sensor, fuel/air mix thingee that you just stated, I have one here that sort of contradicts: my fuel mileage started to really suck last few trips. I had a very dirty stage 1 air filter that I couldn't soak clean and ordered a new one....which I had to wait for since they were out of stock. Got some of the HD de-greaser/cleaner and hosed the filter (got all sorts of funk out of it). Next tank of gas, mileage was up 3mpg. Next one was up 4. More air, better economy would SEEM to contradict the mixture idea. Better breathing, more efficiency?
At some point, the "very dirty" filter is going to affect performance to the extent that you are forcing it to work harder just to suck air into the motor. In a naturally aspirated engine, a high-flow air filter doesn't force more air into a motor, it simply restricts the engine's ability to "suck" air less. That's why they run like crap or not at all when you take the filter completely off. They are sucking too much air.

The motor has to have a given amount of air and fuel to run, so when you are overly restricted, you have to work the motor harder to get it to suck enough air to run the way you want it to.

Both of my H-Ds lost fuel economy when I did the exhaust/AC/Power Commander mod. It's hardly noticeable at highway cruise and as much as 10-15% when you are cranking hard on it around town.

2011 Ultra Classic Electra Glide FLHTCU
Jackpot 4" Dyno Tuned Mufflers | Jackpot 2/1/2 SPC Head Pipe | Cobra Fi2000 PowrPro
chasarms is online now  
post #7 of 9 (permalink) Old 06-24-2013, 09:31 AM
Senior Member
 
StreetBob4's Avatar
 
Join Date: Jun 2013
Location: Tennessee
Posts: 563
Images: 2
I've got the Screamin' Eagle Pro Stage IV Race Kit installed in my new 103 Street Bob. (three weeks old this past Friday). It has 916 miles on it and I'm getting around 41/42 mpg. (93 octane / with REAL gas).....I don't really have anything to compare to but I don't think that's too bad, then again, I haven't been running it real hard yet.

It IS rather 'cold hearted' though. If it sits for more than two days, it takes longer to warm up/run smooth. Characteristic of the motor.

"Nothing wrong with a good shooting as long as the right people get shot"....Robert DiNiro

SE 'PRO' Stage IV Race Kit installed, SE Variable Pressure Clutch, Thunderheader Racing 2 into 1 Exhaust System, SE Orange 'Phat' plug wires, a few other top secret highly classified goodies, mag wheels buffed out by hand, orange engine paint accents done myself, and too much wax...lol
StreetBob4 is offline  
post #8 of 9 (permalink) Old 06-24-2013, 12:17 PM
Mississippi Cajun
 
kd5cqt's Avatar
 
Join Date: Dec 2006
Location: Ocean Springs,Mississippi
Posts: 10,973
OK, Chas, that makes sense. Tnx.

USAF Veteran, PGR Member, Retired Old Fart! 2011 Electraglide Ultra Classic
kd5cqt is online now  
post #9 of 9 (permalink) Old 06-24-2013, 04:01 PM
Luke 22:36
 
Kainam's Avatar
 
Join Date: Oct 2006
Location: Kansas City
Posts: 19,973
Images: 149
Garage
Quote:
Originally Posted by kd5cqt View Post
More air, better economy would SEEM to contradict the mixture idea. Better breathing, more efficiency?
What happens is, yes you do get more air and thus more fuel as well to mix with it at a specific throttle position...


But what happens is you do not need to open the throttle as much to get the needed air/fuel mixture into the motor to go a specific speed.


I only need to open the throttle on my bike 1/8 to 1/4 to cruise 75 MPH where on a stock bike someone would have to open the throttle higher to cruise at the same speed..... and I'm STILL getting 40 MPG on a carbed bike!

'05 Carbed Night Train
111 rwhp, 112 rwtq
Best 1/4 ET 12.557s
Best 1/4 MPH 108.59
Kainam is online now  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Harley Davidson Forums: Harley Davidson Motorcycle Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome