I installed a set of Rush's with 1.75 (conservative baffles) because the Harley tech rep said 2.0 - 2.5's might be pushing the current ECU curves. I haven't noticed any improvement in performance ... other than it now sounds like a real motorcycle.

I asked the rep what it would take to install a "big sucker" the one that has a K&N at the end of it .. and for which they sell a rain sock ... the guy about floored me ... said it would take upwards of a $1000 ... said I would be smart to install a programmable aftermarket ECU and then the big sucker ... and install and dyno time ... plus reprogramming ...

Has anyone installed a big sucker and aftermarket pipes without re-programming? How does it go??

 

get a pcv and a canned map. should be close or get a thundermax and no dyno tune needed as it tunes as you drive or add $1 work of resistors and run the stock ecm and run a little rich but much cooler

 

I suggest you make the investment in TTS Mastertune. Do it right the first time. TTS allows you to remap the Harleys factory Delphi ECM which is a proven and very reliable unit. Although I have never used Thundermax, which is an aftermarket replacement ECM, the feedback I have read has indicated failures.

TTS used to fave the Harley contract for programming the Delphi ECM. They know it. And if you decide to make additional mods in future, you don't have to remap & dyno. You can do it yourself and approach the performance as a dyno-tune. It is without a doubt the best performance mod I have made for my Fatboy.

 

I had a dobeck(250 down the drain thanks dealer) then went PCIII without a dyno tune then had my indy Dyno tune it,I could tell the differance then with no dyno....cost 700.00 for PC and Dyno.I run the Rush 1.75 with full flow AC....Big pic I know....