Increasing the performance of an engine via the crankshaft doesn’t seem obvious at first glance, but it’s worth taking a closer look.The mechanical efficiency of an engine, which together with the thermodynamic efficiency and the delivery ratio determines the nominal power of an engine, depends fundamentally on the diameter of the crankshaft bearings and the friction in the bearings.Of course, you cannot change the diameter without further ado, but you can change the friction, which in turn depends on the bending loads and the resulting vibrations of the crankshaft.This is precisely why the use of high-quality titanium connecting rods is of little use if the resulting significantly reduced rotating masses on the connecting rod base are not also taken into account on the counterweight side of the crankshaft.Because only a perfectly constructed crankshaft that is calculated for the connecting rod weights actually results in lower bearing friction through eliminated vibrations and thus an increase in performance.Furthermore, this crankshaft is speed-resistant up to 11,000 rpm and tested in continuous operation up to 10,000 rpm.A pleasant side effect is of course reduced load on the crankcase and less wear.The crankshaft that can be ordered under this item number is designed using the most modern calculation options using CAD and the FE method (Finite Elements), but is still FIA legal for historical motorsport and compliant with Appendix K, but is designed exclusively for operation with steel connecting rods.The focus was on the FIA regulation that “no material may be added” and that when a new component is manufactured, the original or the newly manufactured component may be lightened, which is exactly what was implemented in this crankshaft.If you want to use this crankshaft with titanium connecting rods, use the crankshaft with item number 1.01201B, which is designed for the lower rotating masses of titanium connecting rods.Failure to observe the mass balance will sooner or later result in the crankshaft breaking at maximum speeds.Furthermore, this crankshaft is an authentic replacement for every standard crankshaft of the 911 from 1965 to 1971, i.e. every 2.0l and 2.2l engine.You can easily replace any 911T crankshaft from the 2.0 or 2.2 that does not have factory counterweights with this crankshaft with counterweights.