Are there any mods to the stock 2005 MCS exhaust that will increase flow without replacing the whole thing? I have 15% pulley and jcw style air intake. I feel this is the next thing holding back performance and the logical third step after reduced pulley and high flow air intake.

 

I did a resonator delete on my 04 JCW. I like the sound better and I think it freed up the flow a little. Cost me $30 at a muffler shop.

 

Is the one ball mod for performance or mainly for better sound?

 

You remove a bit of restriction and weight, then you have a bit more sound. There can only be gain, no matter how little it is.

 

I just want to set realistic expectations. I wouldn't say that the exhaust is "holding back performance". Even a full exhaust replacement would yield only a very small gain (hard to measure or feel). However, you may enjoy the car more because of the sound. Get an ECU tune if you want real added performance.

 

remove the cat and one of the mufflers, there will be a difference. the cat ussually stays with most people tho.

you could cut both of the stock mufflers off and put magnaflow mufflers on, they will flow better

 

Has anyone tried just pipes with JCW resonator?