a 1.6 5th gen ej should run high 15's...your bolt on's won't do shit in a straight line though. All it does is change the pattern of your power ban. You may get higher hp in the high end, but you're getting lower hp in the low end. In autoX it may make a dif, but in a straight line, your implimenting the full RPM and power band which doesn't really help you.