- Flywheel weight
- decreasing the flywheel weight decreases the momentum gained through rotational mass. This decreases MPG and increases the RPM necessary for a smooth idle operation. A weight reduction of 3-6lbs from the stock flywheel is recommended for daily-driven, or similar vehicles.
- Camshaft duration
- duration refers to the time that the valves remain open. Increasing intake and/or exhaust duration can aide in engine performance by allowing the potential for a greater air throughput, and possibly a more efficient exchange of gasses. However, the longer duration, the larger the load duty required for ideal intake velocity. This means a rougher idle and can mean decreased “bottom-end” performance. For a street-driven vehicle, a camshaft duration (intake or exhaust) of no more than 270 is recommended, with 260-264 being more reasonable for daily drivers.
- That being said, many people run upwards of 280 on daily vehicles, but it will be noticeable.
- Compression ratio
- This is a bit more forgiving for a street vehicle, and the range is wider. Running anywhere between 7.5:1 and 11:1 is perfectly acceptable. A good, solid value for performance is 9.5 or 10:1.