I am not sure you worded that correctly, but the process takes into account 'known' gains in IT prep. The 9448V and 16V do not respond to IT prep like average motors. Experts can chime in here and describe why.
Not tha I would call myself an expert and not going the JME route by doing it mostly l on my own, here is what I have learned after 2 1/2 years of eeeeeking out every bit of hp from the S that I can:
#1 Cam Timing: is such in the head of a 944 S that you can not change it (inexpensievley). I've been told that you can play around with shims under the cam tower at 1/10,000 change per dyno run - disassemble, add or subtract, try again...very time consuming and $$$
#2 DME: Porsche has made the dme propriatory and diffficult at best to dynamically change. There are a few companies out there that make street chips, but none that I have found that makes them for our purpose. Once again, JME guts the dme and puts in a Motec - $$$$$ and minimal gains from what I have heard.
#3 Headers: no one has made to date an 'engineered header' for the S. I built one out of pieces and parts from a 928 header, sent it off to MSDS Inc. who made a really nice header for the car. Then Irish Mike and I spent several days playing around with marrying up an exhaust and muffler combination that gave us the most significant power gains than all of the above. Now, other 944 S owners have purchased that header from MSDS only to have it not fit their car. There is no room between the chasis and the clutch housing so it fits some and not others.
Legally, we are not allowed to touch anything else on the motor so we have nowhere else to go but the suspension.
Other than that, there is really very little more to do to the car that it will respond to. Jim Higgs of JB Racing (a real expert amongst real racers) basically says that when PORSCHE originally brought the 944 S to market, they had already built one hell of a power plant that is about as close to 'race ready' as you can find in an off the show room floor back in 1987 with the technology at hand. With that in mind, I have found the 944 S to be a great track car. Most races I only have to torque the wheels, check the water, oil, and air pressure, and watch everyone else work on their cars. No complaints there.......I still would recommend an S for many reasons and I continue to race it in SCCA, PCA, PBOC, and any other venue I can run in.
Mark