Ok, got it. Well, I am going to leave the detailed performance discussions to those of you who have the education, insight, knowledge and gumption to analyze all of the important aspects of whether one performs better than another.
What I can say from experience flying with this setup is; with the ECi IO-340, ECi forward facing cold air induction, ECi fuel injection, Van's stock IO-360 cowl and snorkel, Vetterman 4-pipe exhaust, 1 slick, 1 Lightspeed Plasma II is that I have no complaints about the ability of my engine to breath! She is breathing pretty well with the stock cowl and snorkel. Here is a pic flying back from OSH last year. If you examine all the parameters displayed not sure what you could garner from the data other than the engine is humming along rather nicely!
I kinda like the MAP reading considering that is pretty much where the breathing part comes in.
Way back in the last decade when I was building I contemplated going with the Sam James Cowl. After a great deal of reading and talking with everyone on this forum who would discuss it, Vans staff, and even Sam James at Sun n Fun, I came to the realization that there was going to have to be some additional fiberglass work if I went the SJ route. There was no additional composite work with the Vans cowl. After it was cut I did not have to build up anything, add any fiberglass or redesign anything.
The same goes for the snorkel. Many have posted they had to cut the snorkel and re-glass it to make it fit. Did not happen here! I bolted it up to the intake flange and custom built the bracket on the pilot side intake to hold the K&N Filter and the top of the snorkel. That was it. It fit like a glove (and I am not talking OJ style either
I am sure the SJ will be great but just in case you wish to see how the other side lives please do come say hello at HBC after July 22nd. Lets talk RV's.
Live Long and Prosper!