removing the cat.

[Wildrice]

I doubt if removing the cat increases anything. I have friend that runs a dyno shop. When I had my 2014 Harley Street Glide Special & there were 3 variations for the Exhaust. One upgrade was to run straight dual exhaust, another was to split off behind the header & run twin mufflers, the third was the stock version which ran thru one muffler & then split off at the very end to give the appearance of dual exhaust--on this stock version approx 70% exhaust exited via the pipe in line with the muffler & the remaining approx 30% exited via the fake side.

Any guesses as to which configuration provided the most rwhp & torque??

Well--it was the stock version--straight dual exhaust came out in last place. This is on a Harley, not a Rotax--but most engines without modified tuning will produce more rwhp as is--it needs the back pressure or the ECU parameters need to be custom modified to match the new exhaust configuration. The pants seat evaluation is BS, reminds me of the time a friend said he got rubber in 2nd or 3 rd gear

I do have the chrome Akrapovic on my F3's--love the sound--get's better after 2000 miles

Darrell

 

[rosebelle]

Yeah some of us have gone through the era when more "sound means more horsepower" ,was just a perception.

On the otherside I still get amused at the hype behind mufflers; that people are forced to pay megabucks as if they are some magical modern day technology, when simply they are mufflers that have increased in size because of Decibel reduction required by law.

Granted on the outside they may have nice finish, but essentially they are simply a large pipe with some internal pipe, some plates and some fibre wool. No real magic and no real surprize that removing some inerds often leads to increased performance because they are just a legislated add on.