I've got 2 Harleys. 1 is 2015 Street Bob, 1 is 2013 RGU, so both are 103 engines. Bob is fitted with a Bassani 2-1, RGU is fitted with FuelMoto 2-1. Both with PowerVision's with maps from Fuel Moto.

Bob pops a bit under decel, but runs pretty good. Could use some more fine tuning I think.

RGU runs great throughout the rev range and sounds just as good.

My issue is with heat with the RGU. It's pretty bad, especially on warmer days. From what I can tell, the heat is really radiating from the exhaust pipes.

The Bob runs much cooler and much more bearable when it gets warm outside.

My question is, does exhaust type make a difference in the heat output?

Granted, I am not really using the most scientific method to gauge this (my hand to gauge heat right when I get off the bike), but my hand is calibrated to strict ASTM standards.

 

if you have the fairing lowers on, these direct and order air to the motor...better flow and cooling. ( could be the Bob isn't transferring heat to the air as well)

that means the heat is exchanged to the air...which is then directed at your thigh. the blow dryer effect.
if you have thicker jeans that'll help, and if you keep your thighs to the gas tank, the hot air will keep flowing by and not eddy at the gap between the leg and tank.
most of the discomfort will be on the back of the thigh

luckily, this is a natural riding position for me.

radiated heat:

a "true dual" will have more equal amount of heat on each side of the bike, rather than all on one side.

currently you have all the exhaust on the one side and it can radiate at you.

heat shields on the headers help- and some guys try wrap under the shields there are also ceramic coatings- these are designed to keep the exhaust gasses hot inside the pipe- the hotter exhaust gasses have a higher velocity which is good for performance....if the gasses were to cool in the pipes ( by exchanging heat) the gasses would contract and slow and perhaps eddy



I prefer a 2/1/2 on my baggers for reasons of cost and performance. my fxr has a 2/1


that's me


Mike

 

RGU is running a little lean which causes more heat.. Bob is running a little rich cause of decel popping which will run cooler.. I myself would rather run a tad rich than lean..
Just my 2cents..

 

On my RGU with the lowers on there's a space of still air that roasts your right leg even with the cat removed. My almost perfect fix which increased the airflow to this area was to remove the air deflector that's between the fairing and the tank. Only remove the right one though so the other one still creates enough of an updraft to keep the turbulence down.