i am planing on running all motor have motor dyne spacer & MREV, cold air intake ,test pipes , looking for a good exhaust to go with my setup also light in weight really dont care about price but need rwhp tuning when done with all.

 

no exhaust out is going to satisfy you as far as creating RWHP. I've been on her for almost 5 years and considering that you have most of the parts that free up horsepower on our engines, looking to an exhaust to add a significant amount of power isnt going to happen.

My advice because I've put on (and removed for various reasons) many different test pipe and plenum options, the plenum spacer and test pipes along with an intake make the most power. Exhaust on our cars (except when turbo) add a tiny amount of power and are more for sound. However, Id suggest a true dual exhaust. When i had my greddy evo II converted to an x-pipe rather than a y-pipe, i gained a noticable amount of torque..

Pick something you like the sound of. Greddy = quieter than most. HKS = louder and sound great, price doesnt justify for me. Nismo = I think muffler hangs too low and will get dented when lowered. Note, your test pipes are going to make any exhaust sound mean...especially a greddy...i loved mine when I had test pipes.