
Originally Posted by
GTPpower
Is4 is too big of a cam. It is poorly designed for our heads, it sounds cool, but you will end up building a quicker car with an is3.
Is3 and xpz will make similar power, but the xpz idles a lot smoother, which is why I chose it for a daily driver. However for a toy or track car, you may want something that sounds meaner.