[Namato1]

I have an 04 Sportster and when I installed the V&H Straighshots the deater told me I had to also change the air intake so I put on the SE1 free flow air cleaner and rejetted carb. Bike runs and sounds great. My buddy just brought an 08 and wants to put on the same pipes I have but the dealer is telling him he does not need to change the air intake? What changed on the 08's or do you all think he should still change the intake and reset the FI?
Thanks.

[wvak47]

You mentioned what changed on the 08's. It is now FI. It may need calibrated but the sensors should take over and control the fuel mix through the injectors. Atleast that is what I have been told.

[ringo912]

The new bikes from HD are not equiped with a true closed loop system. Hd has what is called a bias-closed loop system. This system will only make adjustments to the air/fuel mitxture up to 40 mph. After 40 mph the ECM reverts back to the main map.

[hotroadking]

Basically if you just change the pipes to a SE version or something not super free flowing like a 2-1 or drag pipes the ECM's fuel settings will be ok,

However if you put on an Air filter package the bike is really going to lean out.

You can put on a V&H fuel pak or DFO to add some fuel, however if your friend will consider cams, heads, bigger pistons, stroking any further performance mods I'd suggest he look into a SERT (Screaming Eagle Race Tuner) Powercommander or best is Zippers Thundermax with Auto Tune

The zippers replaces the HD ecm and narrow band o2 sensors with a new self learning ecm and wide band o2 sensors, it basically tunes the bike as you ride.

Add cams, it can relearn, you may only have to change a base map setting if that.

Cheaper long run than a sert or powercommander and dynos