I currently have the H-D heavy breather (08 street bob) and was thinking about switching to the big sucker style a/c
will I need to have the bike re-calibrated and re-tuned?
thanks,
jeff

 

I wouldn't. Even though both are free-breathing, I don't think the difference requires retuning. Awhile back someone had posted a chart with the different a/c units and how much air they drew, but I can't find it.
See how it runs and then decide. Is your bike a carb or EFI?

 

It`s EFI

 

I think the EFI will adjust enough for the small difference in flow there may be.

 

What fuel management system are you using? If your o2 sensors are still in tact, the ecm will compensate in closed loop, the difference will not be enough to cause any ill effect in open, although it could if your o2 sensors are bypassed by a PC or other device(cause your open at idle and cruise with those systems). It really will depend on what system you do end up changing to and how it flows vs the heavy breather at X rpm's.

 

I have the SE stage 1 A/C i was thinking of changing to the heavy breather and was wondering the same thing i am running a SERT for the management!