Please tell me the difference between se pro street tuner and the Vance&Hines fp3 fuel management system and which is best thank you.

 

SE Pro Street Tuner actually changes the fuel maps in the ECU and the FP3 interrups the fuel mappings between the ECU and the main harness, the Dynojet PC3 and PC5 do the same, the Dynojet PowerVision will reprogram the ECU as well.

 

Over this side of the pond the Vance and Hines will negate your Harley-Davidson warranty if you have one, the Screaming Eagle will not.

 

On this side they have to prove that the damage is caused by the tuner.