Leo2005 wrote:I'm going to do a custom exhaust with borla muffler.
A few suggestions if you are going custom exhaust:
1) If you are doing a cat back system, do not get rid of the resonator (located under the middle of the car). Instead, fit the largest/longest flow through muffler you can. Not sure what Borla sells, but Magnaflow has a series of 4" diameter (2-3" piping) round mufflers that are ideal for this. The resonator really helps tone down noise at highway cruising speeds with no effect on performance.
2) Look at the Altima and Sentra guys for exhaust system ideas. They have pioneered exhaust systems for the QR25DE motor.