New 2008 Sedan need some tips please

[WeeYari]

Springs

On stock springs, the Yaris has a gap approaching 3" between the top of the wheel and the bottom edge of the fender. Lowering springs will offer a cosmetic improvement by eliminating much of this gap. How much depends on the drop provided by whatever spring. A nice drop is around 1.5"

Performance wise, new springs will be stiffer thereby providing better response and less body roll when cornering. OEM ride quality can be maintained by getting springs with a progressive spring rate as opposed to a linear rate. Progressive stay soft during normal driving, but get progressively stiffer the more they are compressed in cornering.

Exhaust

Aftermarket exhausts are typically loader. Some very load, others with a nice throaty rumble. They will also offer slight performace gains as they are more free-flowing than OEM exhaust. Headers are at the engine side of the exhaust system. Aftermarket ones again provide slight gains by being less restrictive than OEM header.

Intakes

These replace the stock air intake box on the engine. They provide slight power gains by feeding the engine more, slightly colder air. They also add an aggresive sound to the engine under hard throttle as the sound of air being sucked into the engine is not baffled like the stock air box does.

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