For the most part, sizing the cross-section areas is the controlling feature. Taking this yet another step, it's possible to broaden an overall torque curve by tuning the intake and exhaust ...

In today's Thread of the Day, we want to know if you prefer your M3 with high revs or a fat torque curve. Where the 4.0-liter made peak power at 8300 rpm, the 3.0-liter makes peak power at 5500 rpm.