What are they, what do they do,,

They help restore some of the low end performance that is lost when people put straight pipes on their bikes.

If you're running mufflers or baffles, cones won't help you.

A Little deeper down the rabbit hole :
http://www.nrhsperformance.com/tech_arcones.shtml

 

The graph itself shows that they basically don't work, certainly not enough to feel on the road.

 

Knowledge Is Power,,
Research Is a must when we mess with these bikes..
I've talked to several,,they do serve a purpose undercertain conditions.

 

Question, I only have SE slip-ons. I removed the baffles altogether, would I benefit any from torque cones?

 

Maybe - maybe not. You'd benefit more from putting them back in.

 

Yeah put em back In,,If ya want remove some of the stuffing,,not much
tho,,,,

 

with bikes in general a slight change will alter how the bike runs. even more so with efi models. Torque cones restrict exhaust flow. There is no adjustment to them, therefore to get the fuel gas and exhaust mixture would be hard to adjust.

 

This Is very true,,
The Sportster engine was developed to work with a specific pipe diameter.
Changing that one exhaust component Is a Mistake In most cases,,IMO