Originally Posted by pistonhater

I think it is totally reasonable for people who read the thread to simply ask for some explanation/evidence.

Originally Posted by Flashwing

Asking is one thing. Some of our members tend to demand which is totally different.

Originally Posted by HiFlite999

Not trying to be a smart ***, but then why don't they? What's the limiting factor if not the ports?

Originally Posted by Charles R. Hill

The reason rotary builders keep things mum about what they do when building/modifying engines (at least in my own case, anyway) is not a concern for quality but moreso because the rotary engine lacks many things that piston engines have. As such, there is little opportunity for us to differentiate ourselves from one another and we prefer to keep our methodologies to ourselves.

Originally Posted by Charles R. Hill

In a community as passionate, well-informed, and quirky as rotary enthusiasts are, there has been nothing offered as evidence/proof which has settled debates on anything around here......... nor should there be. Any documentation offered can be altered to present a desired outcome. Any claims can be explained in a way so as to sound plausible. Anyone who has spent enough money can be convinced there was some sort of benefit derived from their expenditure.

As for which approach to any situation is the best; I would opine that the only one capable of making that decision is the individual.

Originally Posted by Charles R. Hill

In the context of this specific thread, I would like to offer my own opinions if I may;

1) MazdaManiac can say what he wants about this particular engine and it's airflow characteristics but his measuring abilities are nowhere near what they need to be to make such observations with credibility. His own discussions in the past on this forum as regards the MAF sensor, the PCM, and the nature of his work indicate as much. Without the proper air meter and an engine dyno, any alleged airflow "improvements" are merely speculative and subjective.

2) Evaluating a given rotary engine's performance based primarily on the nature of the "brap" is also nonsense. Disrupted idle airflow, ESPECIALLY with the Renesis, is in no way indicative of the torque output across the RPM band. Such idling characteristics in modern engines is actually unnecessary with proper set up and tuning, and the flattest, widest, highest torque band is what all OEM engineers are striving for when designing any given engine. As such, just like with so many other things automotive enthusiasts and hobbyists do with their own cars, it seems we have here yet another modification of an engine that has, most likely, undone a lot of research and engineering that mazda pout into this engine. With the Renesis, Mazda attempted to squeeze a little more life out of an engine that was having a difficult time remaining relevant in an age of impressive airflow engineering as rotary engines are notoriously inefficient at converting gasoline into motive energy.

3) The location of the pinholes in the ports is quite likely to actually REDUCE airflow at various points in the RPM range. See "The Bernoulli Effect" for a brief example of my concern.

4) The reason rotary builders keep things mum about what they do when building/modifying engines (at least in my own case, anyway) is not a concern for quality but moreso because the rotary engine lacks many things that piston engines have. As such, there is little opportunity for us to differentiate ourselves from one another and we prefer to keep our methodologies to ourselves. In BHR's case, our customers receive a log of all their engine's clearances after I am finished building their engines. Further, whenever we present our work to the public we far more often experience a bunch of criticism form internet "know-it-alls", "armchair quarterbacking", and/or claims from others that they would have done it differently or could have done it better. Those of us who perform these services for our livings already know who the good builders are and who the questionable builders are and most of us are way too busy to be critical of one another's work.

5) To say that $7,000 was spent on an engine build and that another car was faster is an unfair comparison. I have no idea who it was that charged that much to perform an engine build (mighta been one of my engines for all I know) but the only thing we rotary builders can do is use parts that are suitable for use, clearance the engine parts properly, and assemble everything properly. Whatever power the engine makes after that is dependent on many other factors which are often out of the builder's control.

Originally Posted by bse50

Just dyno it and prove us all wrong!

Originally Posted by DailyDriver2k5

Hopefully by the end of next month or no later than August. So be patient, to put car on a dyno in my neck of the woods is not cheap. About $180-220 for an hour session.

Originally Posted by Charles R. Hill

My comment had nothing to do with any alleged "bad blood" between Jeff and myself. It had to do with technical matters, only, and Jeff's own opinions as posted elsewhere on this forum.

What do you suppose it might be with that $7,000 engine that is causing it to underperform to your specs? What are we builders supposed to do to guarantee power output with our builds after we have (assumedly) properly determined which parts to re-use, properly clearanced the individual parts, and properly assembled everything according to the service manual? I am not trying to be argumentative nor controversial; I ask these questions because I am always curious as to the path of logic people take when developing their opinions about things.