I have a tornado I bought for my old CRV. It slowed the air down a lot as it
nearly blocked the intake. It saved gas because you could only accelerate slowly!
I think it helped on the old 8 cylinders it was developed on but more modern
engines are already well designed.
This turbulator helps flow. If you have a tube and try to flow air through it only a
small area will flow (say 2" tube flows 1" diameter of air). If you add some turbulence
a lot more air will flow (say 1 1/2"). That's the theory anyway. I've heard of it curing
flat spots and my impression on the Super Sherpa was it made it more torquey. It
definatly did something. Many times there isn't a measurable difference but seat of
pants feels better (IE K+N makes most bikes feel smoother).
The Yager has a flange at the head but the fuel injector is very close to it. You'd need
something like this with a 28 mm hole;
This is the input;