Originally Posted by FBRR

I can't believe how a "little" information can be turned around!

"removing the baffles could add reversion" THIS IS WRONG

First, removing the baffle "decreases" reversion, it does not increase reversion! Reversion acts to increase low to midrange torque. Therefore if reversion is reduces ( less backpressure by definition equals less reversion!) you may feel less torque at low to mid throttle.
Less backpressure can lead to more Max. Hp. at wide open throttle, IF!!
BIG IF you can get enough fuel to take advantage of that decrease in backpressure!

" it is a closed loop so the ECM will only allow so much air or fuel regardless" This is also technically wrong!

Second! The ECM has no control over AIR into an engine ( except in the case of drive by wire where the throttle is opened by the ECM software but opening the throttle is not part of close loop control ECM control during closed loop is a fuel only correction! Not AIR). But even then the restriction to airflow is the intake ( aircleaner and exhaust) not THE ECM software control.
The ECM only attempts to maintain the correct air/fuel ratio through closed loop operation! ( by changing delivered FUEL, the ECM cannot change airflow! That is a function of restrition in the air cleaner!)

The "ECM" or more correctly the ecm software the controls fuel, can modify fuel slightly. And if you only open the exhaust, there should be enough "learning" to compensate for a little less backpressure. If you also open the intake ( aircleaner) you then would need to have fuel modified through either re-programing or an add on device!

Even with "just an open exhaust" there is a possiblity that during open loop operation at Wide Open Throttle(WOT) you can still have an overly lean condition! Some closed loop "learning" affects "open loop" fuel delivery.
But it may not account for every "speed and load" point during WOT operation! And without proper A/F ratio at WOT, you will not gain any Max. Hp. by the decrease in backpressure!

Bottom line, you will most likey not need a "fueling" device for just an open exhaust. You will most likely loss some low and mid-range torque. Without adding fuel you will not gain HP. at WOT!

I hope that allow you to make a more informed choice!