[Sebringjetta]

Originally Posted by bradleyland

The Z4 isn't naturally aspirated either. The engine used in the Z4 GTE/GT3 cars has nothing to do with the production engine. I believe they still run the BMW P65 engine, which is a flat-plane, race-only engine.

My point is that it's not unusual at all for manufacturers to run a different engine in race cars than they do in street cars. That's not to say I think they're going to continue running the P65 though.

As Blipit and tallshortguy are discussing, we're at a bit of a transitional point in automotive racing. FIA F1 has gone forced induction again, and the smart money is on IMSA (and other sanctioning bodies) following suit to make their rules more favorable to forced induction.