I wanna use v&h big radius on breakout can I use it without buying fp3

 

You can, but you would have much better results with a tuner of some sort.

 

Just make sure you check the build year of yr bike as the O2 sensors changed from 18mm thread to 12 mm thread from 2012 and later for certain models. And as stated by skid_pimp you will need to do some tuning to get the bike adjusted to this modification, otherwise it will just be an esthetic mod.

 

And as well with no tune you will have most likely decel pops which are with a big radius 2in 2 quite loud. I've had that experience with mine V&H. After adding some more fuel during the decel phase in the tuning settings it got resolved. I hope you will like the loud sound.

 

Why would you want to? These bikes run lean, changing exhaust only worsens the issue. You have invested money into a nice bike, treat it with the care it deserves!

 

What is another $399 bucks to make the exhaust your spending $700 on actually work for you?

 

i have that exhaust, on a fxstc. The popping is pretty bad, and the bike heats up alot if you dont tune it once the pipes are on there. You can ride it without tuning it when you put on pipes but if you plan on keeping the bike for any length of time i would get the FP3 if i were you.