+ your not going to notice the gain. You will notice the noise in your ear though.

 

i have a 5/16 plenum spacer and z tube
looking to get the mrev2 soon

 

Holy ****!
You found yourself a Gold Mine.
It's called The Exhaust 250 Top Of The Line
It's the exhaust that HKS & ARK based their design on.
Your So Lucky!

 

Well, 1st make sure it is that and not some knock off.

 

heres another pic

 

its an ebay knock off. They are great exhausts for the money imo...

 

Gains, yes. Noticeable, no. You're lookin at a handful of hp tops. The more you have done to your car, the bigger the difference....but still, it's not going to be like you just strapped a rocket to your pants. If you're lookin to have a loud car, go for it.

 

its most likely a replica HKS sold on ebay as X02 or M2 or various other names. and you can get a brand new one for $350 i wouldn't waste my money on this. they are also known to have some fitment problems