How restrictive is the stock boxster muffler?

[mts]

Originally Posted by mptoledo

Now that is a great answer, not just an opinion, but supported by facts. Kudos I really would like to know if you gain any resonable HP by bypassing or removing the cats. My first car was a mgb ltd. 1st thing I did was take off the cat and put headers on it. it really put some pet in that tiney engine. I have been following some of pedros mods, but he never tells how much hp you gain or even an estimate. Since I am keeping this I want to squeeze out as much juice as possible.

http://www.pedrosgarage.com/Site/DIY%20Projects.html

My car dyno'd in the 5-7 additional peak hp range before/after adding the Fabspeed cat bypass pipes. Better than nothing, but not a lot better than nothing. On the bright side they are a heck of a lot lighter and sound cool.