Hi Wayne,
I appreciate the civil attitude you have cultivated here, these things can get out of hand. I can be really bad myself at times, but, I always start out respectful. I hope others make a concerted effort to remain cordial as well.
In reading through everything, and having a pretty solid working knowledge of the way engines work in regard to fuel injection, air induction and such I have some insight I'd like to share. I hope this opens a discussion and learning opportunity for everyone to better understand how things work.
Funny, back in November I got into a thread discussion where a guy who was claiming that Variable Valve Timing was a way to eliminate pumping loss, I thought he was full of it, but this led me to research the whole VVT thing and really cemented for me how it is that intake systems control the power of engines. The thread is
Warm Air Intake (WAI) vs Cold Air Intake (CAI) ... School Me and worth having a look at.
Based on this, and the knowledge that Pumping Loss is the only real area that the Gadgetman groove concept can have an effect on to improve fuel economy, I see no way the his modification can improve an engine in order for it to run more fuel efficiently. At the end of the day, I think the engine management system will compensate for any perceived imbalance that it sees between what the Mass Air Flow sensor is telling it and what the Throttle Position Sensor is indicating.
His trick in theory is to put the engine in a lean burn condition whereby the fuel air mixture leans out due to more air being "snuck" into the engine via his modification to the throttle body, I could be wrong, but I believe the engine management system is smarter than this and will compensate for the extra air and keep the fuel air mixture the same.
Modern engines are 98%+ efficient at burning all the fuel that goes into the cylinder, so looking to improve fuel efficiency by claiming to promote “Better Combustion” is ridiculous. Pumping losses are a result of the cylinders in our engines needing to pull a small amount air into the cylinder in relation to what the cylinder is capable of pulling in. These result in about 3% of the energy produced by the engine being wasted on this process. No modification of the throttle body can eliminate this loss.
So the only 2 efficiency losses in an automobile that a throttle body modification can possibly have an effect are already very small, and the mod does nothing to improve either.
Your car needs X amount of power to go a certain speed, and unless you can improve the efficiency of the engine to create the same power with less fuel, you can’t get better mileage. Since there is no way for an air intake system change alone to improve the fuel efficiency of the engine, the idea of modifying it to improve mileage is doomed from the start. People who say otherwise are simply trying to baffle with BS because they know 99.7% of the people out there don’t have a clue about how the air intake functions to control the power of a car to begin with.
As always, there is a 1% chance I’m wrong, and would love to learn more if I am, so school me.