called dealer today and asked if i just wanted to change slipons what would be required to do this. he says need to tune for just slipons .i know i have read here that people were doing this and having no problems .has anyone actually checked a/f ratio after just replacing the mufflers?

 

Visit Fuel Moto and begin reading near the bottom (the large blurb) where it says: "Because of the large amount of questions"

http://fuelmotousa.com/harley_davids..._commander.htm

I am in the same boat as you but think the answer is really yes, you really should put in some form of Power Commander because you are making a "lean motor" even leaner. I myself will buy from Jamie when he has the 09 EFI PCIIIs ready to go.

 

edited to be nice.........

 

i did find the part you were talking about .guess i'll be doing some srt of tuner even for slipons thanks

 

The question is back pressure.
If the new slip ons decrease back pressure as all good exhausts should the engine will run leaner.
I they some how do not then you would be fine.
Question is, how would you know with out a dyno.
I still think having the bike dyno'd after all the engine mods and then flashing the production ECM is the correct way to go.

 

pled55;

I just did the research on air cleaners and slip-on muffler replacements. According to the HD parts manual, EITHER a high-flow AC or pipes will require a remapping of your ECM/dyno tune, or the addition of something like a Fuelpak device (no dyno tune required if you're using V&H pipes).

These things run lean from the factory anyway - opening up the exhaust without doing anything else would just lean everything out even more, creating more heat. Not a good thing for an air-cooled v-twin.

I've become convinced that if we're going to change both air cleaner and exhaust to open the engine up, the additional fuel management device is mandatory. It takes into account the additional flow characteristics of the high performance parts AND leaves you with a fatter fuel/air ratio. Fatter fuel/air ratio means less heat, better throttle response, more HP and torque.

Hope that helps.


Bryon

 

just did a install of Kuryakyn Krushers and no additional mods, bike runs same and back pressure is noticable but no to much to cause alarm

 

On page 505 of the 2009 Harley Catalog of parts-Screamin' Eagle Stage I air cleaner for twin cam models has an * stating "recalibration is required..." as well as other air intake systems on the following pages too.

For the exhaust section about Screamin' Eagle slip-ons pages 516-525 nowhere does it mention the need to do any recalibration. The only * is to remind you to buy muffler clamps.

I guess the needs to be recalibrated may be one of those extra profit margin items that gets mentioned to try to boost profit for exhaust only sales.

Just a thought- I'm not sure.
Hoagie

 

i see what you are saying .lots of good feedback here and i apreciate everyones response
but i think i will more than likley lean toward some kind of tuner just to be safe .i really need my head examined because the bike runs great and it really don't sound all that bad.

 

The 09's do sound good, and with that 2-1-2 system, probably not to shabby on efficiency.

Instead of pipes/pc III or fuelpak, why not just get a TTS Mastertune ($425 or so delivered).

Tune it for max power without all the noise. Put on a high flow Air Cleaner and tune it again. Only go with more open pipes if it just doesn't make enough power, but it will get noisey.

Just my nickle.