I'll say this. Not in defense of the CRB, but as just a factual issue, ITB seems to have the greatest cross section of cars in IT. Seriously, there are cars from the 60s, and cars from 6 or so years ago. So it represents a huge change in technology. And that makes classing difficult.

I'll let Andy expand upon the factor applied to cars in ITB, specifically the 30% 'standard' for 16V cars going into ITB. He's got the best handle on the situation, but, generally speaking, when first adopted, I think the Process represented a bit of fear of 16V cars. (I was just coming on board the ITAC at this point) I think this was due to some problem children that were 16V. As it turns out, those cars were over achievers for different reasons, like under rated factory HP. But the Process suggested higher power factors for those cars. It also said "Discuss to make sure this makes sense" for every classification.

In the Great Reorg, certain cars were classified with higher factors than 25%, especially in ITA. See reasons for that above. And subsequently, there have been some classifications of 16V cars in ITB. (2 at 30% that I can think of) The CRB has been very insistent that 16V cars going into ITB MUST be at 30%. "That's how we were able to agree to put 16V cars in ITB" they say.

(It should be pointed out that, some people have set ideas of what 'kind' of car fits in what class. For example there was a distinct opposition among certain ITAC and CRB members against putting the American Pony cars into ITR. "They'll ruin the class", "It will look like a stock car race", "ITR is for SPORTS cars", were some of the remarks. And there is, among some members, the feeling that ITB isn't the place for "new" technology, like 16V cars.)

Anyway, somewhere along the way, the "Check to make sure this makes sense" clause resulted in most 16V cars NOT getting the higher gain factors, and in some cases, lesser factors than standard. it became the operative standard to start at 25%, and entertain evidence to the contrary. If none existed, the cars are classed at 25%. It's been that way for -3+ (?...Andy?) years now.

Additionally, adjustments where we knew something have been made. If the data exists and has the confidence vote of the ITAC, the weight will be calculated using actual hp. The recent RX-8 adjustment is an example.

So, at the time I left the ITAC, there was disagreement regarding a number of cars in ITB, most notably the MR2. The CRB insists that 30% is the right factor, the ITAC insists 25% is the standard, and that's before actual numbers are used. A case could be made to use 20% based on evidence.

Now, why haven't the issues occurred in other classes? Well, ITC sees little committee action. ITA...I dunno. ITS and ITR have their situations, but they are different.