It is impressive!Impressive - would like to learn more on engine build to support this.
And the chances of you finding out are ZERO!!!!!! You are absolutely right. A LOT of secret stuff, and the ones going fast don't want the ones not to find out how. I forget if this is the class, but basically its externally appearing stock, and internal mods even as far as displacement are allowable and pushed to the just past the letter of the rules.It is impressive!
I too would like to know. My guess a lot of money and secret squirrel stuff going on!
I like the exhaust manifolds too! Maybe they are extrude honed for better flow? (secret stuff) lol