I went from wild pig slip ons to the Thunderheader 2 into 1. My dyno tuner said to gain power go to the Thunderheader.On the dyno I gained 3 hp and5 ft lbs of torque on my 06 street glide. Everyone I ride with says the sound is REAL BALLSEY!

 

I have thunderheader slipons with samson 2-2 head pipes on 04 road king custom. It sounds and runs awsome. Everybody makes thunderheaders out to be extremly loud, I dont think they are obnoxiusly loud they just sound damn good.

 

Just be careful with the Thunderheaders and Performance Parts because they will get louder the more Pump that you throw at them

 

Setup/numbers in sig.

 

As stated above the more engine mods you do the more Ballsey it will be and sound. I love my 2-1 Thunderheader. Is it the best 2-1?? Probably not, but I think it sounds the best.

 

Some of the 2-1 guys act like your gonna get 20hp more than slip ons. We all now the 2-1 is better for performance but your talking about a couple horsepower. and a few ft pounds of torque. I'llkeep my slip ons until I see a dramatic increase.