We can modify the stock muffler for $140 for more flow. It looks stock, sounds mostly stock. Flows a little better.
http://roadraceengineering.com/blog/?p=1161
We make an axle back muffler that replaces the rear section of stock exhaust system. It is $380 installed.
We also sell the Magnaflow cat back exhaust system for $540 installed. It sounds a little louder and sportier than our axle back exhaust (they both use the same muffler) It looks like this:
http://roadraceengineering.com/ralli...naflowcatback/
An aftermarket intake will not make much additional power with the stock turbo. Just go with a drop in filter from Cosworth. $43
http://clubralliart.com/showthread.php?t=207
A stock blow off valve from the EVO X will hold more boost than the stock plastic RalliArt blow off valve. They are $160 new. Used as cheap as $75 or so. The BOV from the EVO 9 works also as an upgrade, essentially the same thing.
If you will one day be upgrading the turbo to the larger turbo form an EVO X then the AEM intake for the RalliArt will work now and be adaptable to the EVO X turbo later on. $250 for the AEM intake and $80 to install it.
http://roadraceengineering.com/ralli...rts/aemintake/
This is what we do for a basic power upgrade on the RalliArt:
Modified Stock Muffler $140 Installed
or
RRE Axle Back Exhaust $380 installed
or
Magnaflow Cat Back $540 Installed
EVO X FMIC Used $200 to $300
EVO X BOV New $160 or you find one used
Install EVO X FMIC $200
Cosworth Drop in Filter $43
Custom Dyno Tune $400
This works out to 255 WHP to 270 WHP depending on which exhaust system you go with. Stock RalliArts make about 210-215 WHP on our dyno. With just the airflow mods they make about 220-225 WHP.
At this point everything is still very reliable and can be easily reversed if the car needed to go back to the dealership for warranty purposes.
Mike W