Significant Recant - The New M3/4s are not Under Rated (long, technical)

[Moderator]

Originally Posted by KennyPowers

its because you, whether you realize it or not, have a confrontational tone in your posts and the thread was almost certainly trending in a direction to have another argument about simulation vs dynos which was completely off topic in that thread.

Absolutely correct. And other members have now also been warned as to their argumentative attitude and history of taking a thread off-topic for the sake of arguing and disagreeing for academic sake. There have been numerous complaints about certain members from the general membership over a long period of time now.

Such posts and attitudes will continue to be moderated, and there will be no discussions/debates as to this policy.

[swamp2]

Originally Posted by KennyPowers

A lot of people asked the same questions of dinan as you did, swamp. its not like you came up with some sort of special question that no one had thought of.

Not correct. I raised many of the same questions as others and raised many absolutely no one else have asked. Again refer to numbered list above.

Originally Posted by KennyPowers

its because you, whether you realize it or not, have a confrontational tone in your posts and the thread was almost certainly trending in a direction to have another argument about simulation vs dynos which was completely off topic in that thread.

Hey, a thread with "data" showing a controversial and frankly, not very believable result deserves discussion. If you don't see the role of simulation in such discussions then you are missing the forest for the trees. I'm sure you also realize that your tone also escalates to ad hominem as well. Also, since when is confrontational either impolite or against forum rules? I never deny being confrontational or aggressive but I very rarely break forum rules. Similarly, because I feel like a long term community member here, I very often try to help self-moderate threads with suggestions to stay on topic and keep the discussions about the topic not about the people.

Originally Posted by KennyPowers

As for the F type, looking at the power curve (supercharged car), it is almost a blend of a normal N/A curve and the flat f8x curve.

See here

http://www.dynocomp.com/blog/2014/01...ar-f-type-v8-s

Thanks for that. Of course whether or not that is the "correct" shape/character of the cars power depends on ones belief that chassis dynos and engine dynos produce the same results, which they dont... Either way the conclusion from that dyno is a 4% under rating.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

And your flip-floping is also duly noted. However, this time I'm also using your prized Quarter Jr software....

I assume you meant my initial comment in this string?

"First, thanks to Swamp for a ton of work, and some really good insight. I know he understood how controversial his position would be, and he was looking for some educated discourse and points of view.

And he got those, for the most part.

Having said all that, my opinion is that the M4 really is pretty significantly underrated, or the BMW marketing guys were sneaking into the garages at night and turning up the boost screws on all the press cars. Here's why I think this:"

If so, re-read, please. I applauded your effort (and still do), not your results.

Originally Posted by swamp2

See numbered list above. Let's have the details. I do not for one moment challenge their experience however, losses are elusive, period, we both know that. Equally so on inertia. What loss did they use and how was it obtained? Their thermal control appears wonderful and I commend them for the amazing attention to detail in that process, as noted above. However, there is a fundamental difference between repeatability and absolute accuracy.

I am not suggesting such questions should not be asked or answered. My respect for Dinan remains, however, so I am quite sure they haven't made any rookie mistakes.

Originally Posted by swamp2

Also, what happened overnight to your pretty strong agreement that the car is making right around 450 crank hp? Heck, what is 30 hp among friends, right? Your credibility via an instant change of mind on this isn't looking so hot either.

I continue to stick with my 450 HP estimate, as I have all along. This 484 HP number is out of wack, but more or less matches those 420 plus chassis numbers generated elsewhere. Of course, you know my position in regard to the more or less "automatic" use of correction factors, which are obviously not warranted while testing the new M engine.

Therefore, the only real question in my mind is what sort of correction factors Dinan uses. If they used little to no correction (based on their control over ambient conditions, and/or knowledge of how BMW manages power under all sorts of conditions) then I might have to revise my estimate upwards, as I have a lot of respect for their shop.

Originally Posted by swamp2

I only wish I knew everything I know now at the time of that GT-R debate. However, I still do recall some significant consensus that the initial model year of the car was probably under rated at least somewhat. So yes I adjusted my thoughts on that just as I have here.

That really was a hell of a debate, was it not? Everybody learned something.