Exhaust Systems....Researched

[mrnickleye]

Well, it is estimated that going cat back , and larger pipe (2 1/2" in our N/A's), will get you about 5-10 hp.

In alot of cars, it is estimated that putting headers on will get you about a 10% gain. But that because those cars had restricted exhaust manifolds.

The N/A motors have a nice, free flowing, and light-weight manifold from the factory. Toyota spent a lot of time and $$$ developing that manifold to give you the best "bottom-end" torque, with out a big loss on the top-end.

I still have my factory one on. I drive it every day, city mostly.

As you read in the first post, "Before this exhaust mod, the car would max out at 125mph.

After this mod, I can easily go 145mph any time I want."""""

Some of the other folks here may be able to tell you about their experiences with headers, and what gains they have gottn,