Chips & Headers were taken away because there were actual dynos to show that people could make significant HP with many hours of dyno tuning various chip & header combos. This year, custom chips made for GTS were shown to make 4-6 on a spec car. Taking these away was simple, had little to no net cost for those affected, and made making HP in 944 Spec motor much more difficult. All good things, and needed to be done. Even the best rule changes like this hurt (it took SoCal at least 2 years to recover), but are sometimes needed. The lesson is that we should not take rule changes lightly.
No one has shown that 147/142+ is currently possible without chips & headers. IMO, that rule change has done its job. There is lots of speculation about what is possible, but current reality is that a home built motor won every race at Nationals, running away from "pro-optimized" (to coin a term) motors by nearly 2 sec per lap in the Championship Race. Right now, a national championship caliber motor can be done for around $3K, and last for several seasons. This is not Spec Miata. As Joe, mentioned, the sky is not falling.
What about the future? With regards to "pro optimized" engines, it is a time for close surveillance. We need to look for outliers, find how they make power, legal or otherwise, and tighten the ruleset as needed. It needs to be known that if you are exploring "gray" areas in the rules, you may become a guinea pig on how to tighten the rules, and have your gray area made black and white going forward. Don't complain when this happens, you have been given fair warning. Conversely, if you are not pushing the envelope, you should be able to enjoy a stable ruleset, without having to deal with dynos, or uncertainly. While TM data is not precise enough to justify DQ'ing people over, it may be good enough to identify those motors needing closer scrutiny. Certainly dynos are good enough to make this distinction. We should take a close look at those "outlier" motors to find how they're making more power (when this happens), and tighten the ruleset as needed. Minimal pain (we only hassle the guys making the most power), and we learn how to improve a good ruleset, rather than go an entirely new direction.
As far as low compression motors. I've run one most of the last three years and, like Joe, I'm of the opinion they can compete. However, this remains an issue, and given the choice, we'd all like 10.2 pistons, I suspect. I see several options here:
1) Gather more data about the actual differences (head to head dynos of fresh low & high compression motors?), and make no rule changes now.
2) Allow a spec'd offset crankpin to fix the timing issues that shaving a head causes
3) Spec a widely available, lower cost aftermarket replica of an '88 piston.
4) Spec a weight penalty for '88 pistons (simple, but can be a slippery slope).
Keep the comments coming guys!