So I want to build a autocross track car but with the N18 engine restrictions I can't accomplish what I want. Since the n14 is much easier to tune I am toying with the idea of swapping my R58 to a n14 engine to keep the mininess of the car intact. Besides the engine, ECU and wiring harness. What else do I absolutely need to bring over for a problem free swap? I'm assuming being the frm from the n14 will make things easier as well since it's all vin coded. Maybe the cas as well? Currently a hypothetical idea but am strongly leaning to it. Thanks.

Edit Example of why I'm asking this. RPM powered has accomplished a 650HP n14 mini build but hasn't achieved over 350HP N18 with same turbo and bolt ons.