I was wondering is the theory the same on the touring bikes if you have a header and say 4" "mufflers" with nothing in them, since it get som much bigger won't the velocity dropping
Work as back pressure at least to a point. Just a question and idea for the op

Thanks

 

NO...... Allows for more reversion.....

 

Thanks I wonder how much faster that old shovel would have been with more than torque cones and 3 inch tips
I guess I'm the odd one don't like quiet bikes

 

No..... You can have loud pipes and Performance. You just need the right pipe....

 

Answer, every bike out there with wide open pipes have a improper tune, they can't be tuned.

Redneck translation of last post:

Drink a 12 pack of Natural Light, eat Mexican and your back end will have waste coming out it faster than your body is prepared for, your body isn't going to be able to run in this condition or fill the stomach quick enough and called scavenging.

Drink 24 of any beer you can get your hands, eat Mexican plus 6 White Castles, your body is going to have excessive waste out the back end plus the inlet is to going purge not allowing anything else to enter the stomach, this has similarity to reversion

 

I disagree. Dr.L's Sportster has a proper tune and open pipes. I had no trouble tuning it with some logging.

 

Not possible to get a perfect tune, numbers might be right going down the road but will be lean during decel at any speed with open exhaust and even EFI can't recover when getting back on the throttle. Data logging systems are slowed down to blend AFR's for tuning but live the open exhaust leanness is alarming.

 

I want lean on decel. There are points where I turn the fuel off on decel. That's about as lean as you can get. I guess it comes down to "what is perfect?" The bike runs great and has no flat spots.

My point is that if you have complete access to the fuel maps, an oxygen sensor, data logging and some time, you can have no problem tuning out any issues that an open exhaust may cause.