It's not Porsche specific but gives a good insight on what is needed for high output motors. http://dsportmag.com/the-tech/how-to...of-any-engine/

 

In the perspective of 944 engines, just points out the same issues it has: weak and dancing cylinders. Other aspects like head flow, rigidity (16v head), head clamping, crank strength are good, even stock rods are good for 500hp if redline is not raised much.

If one eliminates two main issues with 944 engine, oiling (dry sump) and weak cylinders (Darton sleeves) then it is an excellent engine.

 

Having the headstuds so far apart doesn't help but there's not a lot you can do about that.

I'm talking more about the motors that are built or being built for over 500bhp and 6000rpm. More like 650+ and 7500-8000rpm.

 

Patrick, I have something interesting for you.
http://www.fullboost.com.au/fb/index...hp-mazda3-mps/

This is my mates car, a Mazda 3 MPS. 2.3L (built bottom end) 16v some decent head work, stock cam, custom intake, custom headers and a few other things.
It has a GTX3076R turbo on it. Not sure on the rear housing, either a .82 or .63

550hp @ 30psi at the front wheels!!

 

Yes, agree, that when wanting 150+ hp per cylinder for prolonged periods it is different, but my point was that 944 engine is quite good platform despite its few issues.

The famous other engines also have its problems (RB26 engine oil pump issues, BMW M engine VANOS problems etc).

I ma using basically stock 944S bottom end (milled pistons and 951 RARST rods) and it holds fine at ~500hp though I have not taken it to the track for 30-40 minute sessions or similar. Just few drag races, auto-x, sprints.