[Henry Schmidt]

All 911 based, air cooled Porsche engines since 89 have this type of oil flow. 946, 965, 993, TT all have reduced flow with no indication of head temp or oiling (additional wear) problems.
It is true that all of these engines ran improved cooling with duel coolers.
The duel coolers were added in conjunction with the removal of the engine mounted cooler. I'm guessing that the Porsche engineers calculated BTUs generated by the 3.6 engines (both NA & Turbo) and using hydrodynamic and thermal conductivity calculations, determined oil flow and cooler efficiency before proceeding down this path.
They (Porsche) had 9 years of production and 17 years of highway testing with no apparent indication of any problems.
Supertec has used this restricter technique since the mid 80s and we have never seen an issue in our early engines in both race and street applications.
We actually made restricters before we could buy them.
Now it's easy, just call Pelican Parts and order yours.