Shawn Smoak talks about cat removal and loss of power?

[mstngken]

At about 2:45 in the video he claims stock spyders walk away from cat deleted stock muffler ones. What are others view that have done this my thoughts is this ACE engine would be tuned to run with cat?

Here is the video

 

[Bob Denman]

A certain amount of backpressure is needed... It helps to build the bottom-end pull. :thumbup:
If he works for a dealership; it'd be understandable that he's going to be reluctant to suggest that anything other than a stock setup Is best...

 

[PMK]

Shawns a smart tech no doubt. If he was riding the Spyders that got smoked or he had solid dyno run on machines that had enough time between runs to let the computer reset itself and get smart, then posted his results I would be more accepting of his blanket statement.

My rear end, and the wifes is pretty certain or machine pulls stronger with the bypass installed running a stock 14 RTs muffler than an entire stock exhaust.

Yes some back pressure is needed. A straight through setup may not be best.

The again, Dennis posted he felt the two brothers with the cat was best, but required the muffler outlet restrictor. While Shawn really was displeased with the Two Brothers.

Now what. It is all words until the dyno spins and logs the data...

PK

 

[farmer4ia]

tests in gen discussion

check out the post in the general discussion on sharing performance modification data. It gives 1/4 mile speeds with cat and bypass and 2 bros pipe. Very interesting

 

[jcthorne]

I also felt a marked improvement in performance with the bypass pipe into the stock muffler on my F3S. Really would be good to get some of these on a dyno for real numbers though. Shawn compares to a Two Brothers with the bypass. That may indeed be too free flowing and decrease torque. Would really like to see bypass with stock muffler against cat with Akropovic.

 

[one2doo]

I also felt a marked improvement in performance with the bypass pipe into the stock muffler on my F3S. Really would be good to get some of these on a dyno for real numbers though. Shawn compares to a Two Brothers with the bypass. That may indeed be too free flowing and decrease torque. Would really like to see bypass with stock muffler against cat with Akropovic.

I agree