Not a Datsun Z related topic - but I thought I would share and good info none the less.
Just got back from a dyno run on my Turbo Corolla (4AG engine) and I changed the exhaust cam sprocket to the HKS adjustable "slide" one. I only did the exhaust side as we did not want the power band to shift too high (if the intake side was also done). Only took 20minutes to change and make sure everything was lined up.
I retarded the exhaust cam sprocket 2degrees and picked up 3hp at the wheels, and the midrange power band was greatly improved. In other words, the rpm band where you would drive daily was improved - to me this is very important as I do not believe in winding the beejezzus out of my car.
The car had a welded diff, so I am sure the 3RWHP would translate to an easy 20-22% driveline loss or an easy 4hp at the crank.
May not sound like much - but really I thought this was great especially the midrange improvement. Any gain is definately an improvement no matter how small.
Thought I would share as, there has been many conversations back and forth as to what the real gains are to adj. cam pulleys on a twin cam engine, but no real results have been posted as yet. Sorry I have no dyno graph to post as the printer was not hooked up when we did the dyno run.
The car ended up pulling a total of 202WHP at 7psi which I was very happy with and is much much better to drive.
Regards - Yasin