2 Dyno or not 2 Dyno - Harley Forum

vin2k · #1 10-21-2008, 10:00 AM

That is the question...
Here are my specs:
2008 FXSTB, Stage II, SupperTrapp exhaust, free flow air filter, Power commander. Also, this is a closed loop EFI system.

I want to put on an after market air filter, probably a wimmer or force winder. I was told that I would have to put the bike on a dyno after the air filter is installed. Is that true? Doesn't the PC module and the closed loop EFI detect the changes and automatically adjust?

Thanks in advance for ya'lls advice.

frisco-rigid · #2 10-21-2008, 12:57 PM

Hey Vin

EFI has a small amoumt of adjustment in it, some more than others..

You can get to the point where it doesn't adjust anymore.. You're probably not there yet..

However, with those changes it might be good to at least see what the A/F numbers are at diff RPM's..

A dyno run for this would not mean a "horsepower-torque" run, it would mean just going through the gears easy style as though you were rolling down the Blvd. and one a wee more aggressive like you are entering the Freeway and having the sniffer read the exhaust..

Have a ball..

rjrivero · #3 10-21-2008, 02:55 PM

Do you have a PCIII USB or a PCIIIEX USB? The reason I ask is because the PCIII bypasses the o2 sensors, and eliminates the "closed loop" areas of the ECM Map, whereas the PCIIIEX maintains the o2 sensors. It does not modify the closed loop areas of the ECM program, mandated by CARB.

grandlp Tom · #4 01-02-2009, 12:02 PM

For your piece of mind and a better running bike, YES.
probably dont have to although.

#5 01-02-2009, 01:03 PM

DYNO tips at Harley DYNO Testing