That 8-10 HP is a joke. If you get any performance gains its because that muffler is less restrictive and it would only be worth 1-2 HP maybe. And I highly doubt it. Also your going to have to do some custom fabrication as our exhaust is 1.75" not 2.5". So if you did what Mazdamatic has done and straight pipe 2.5" then 8-10 HP would be possible but that's not due to the tin can at the end.
do you guys recommend anything else? im just looking for muffler no exhaust system as i'm not really into performance that much yet. The only decent exhaust i have found is the Racing Beat exhaust which is a bit a pricy for me though
Youtube is your friend. If you wanna go cheap, just throw a glasspack on there. Personally, I would go with a reputable exhaust company. I have a borla muffler.