Can I add thunder header slip-ons without adding a tunner? Planning on keeping the stock air cleaner. The HD dealer told me I could do any slip-on except thunder headers?

 

No tuner required for slippons & stock AC. Sound like HD wants your $$$ though.

 

slip ons you do not need a tune.......and by the way thunderheaders sound awsome....my buddy has a set...and i love them...

 

I've had TH slip-ons for about 2 weeks ('bout 500 miles). I'd heard they blued almost instantly, but mine are still shiny as the day I put them on. I've checked my plugs a couple of times and they show no signs of running too lean and hot. They do gurgle on decel which sounds awesome, but no backfires or pinging.

 

You can't be the sound of the thunderheader. I've ran one on all my previous bikes except this one. I went with bassani slipons this time. They sound good, but they aren't nearly as deep sounding as the thunderheader.

 

06 Classic with vance true duels and thunders, u SHOULD tune with these as decell pop is bad for valves. running power commander and gained almost 12 horse with this setup on stock motor.