[Noir]

Originally posted by mbtoloczko
The best first mod you can make to your exhaust system (if its legal in your area) would be to cut out the primary cats. Cutting out the primary cats allows the primary pipes coming off the exhaust manifold to act as header pipes. This is because among the cylinders on one side of the engine, there is no exhaust overlap, so at any given time, only one cylinder is exhausting into a primary pipe. Once the primary cats are removed, exhaust scavenging (by means of sound wave reflections using the secondary cat chamber to cause the reflection) will be improved. Cutting out the primary cats should give a boost in HP around 5000-6000 rpm.

There two technicalities with performing this mod. 1) The exhaust tubing before and after the primary cats are different diameters, and its important to maintain the same tubing diameter. 2) The tubing diameters are non-standard sizes for US tubing. 1.875" diameter tubing matches the diameter of the tubing before the cats, but its kinda rare.

If you can find the tubing, the mod should cost no more than $100 (including the tubing). This mod should improve power and add some growl to the exhaust note.

Hehe. That's exactly what I'm doing to mine.