by panic » Sun Apr 12, 2009 4:16 pm
On a highly developed engine using a tuned intake length (and different cams), changing the intake length will bump the peak torque around slightly - but typically it will not raise the actual torque, and a spacer will reduce the effective RPM, thus lowering peak power.
In a VVT engine with a few thousand hours of research and dyno time in it - don't you think one of the few thousand Toyota engineers would have said "why are we killing ourselves developing more cams - let's just put a spacer in here?"
There really aren't any easy and cost-effective ways to increase the efficiency of any of these engines. Those products are made by a process that exists in the cosmetics industry: it doesn't matter if it does anything, because no one will buy it twice, and few will admit they made an error (classic example: when your girlfriend was horribly butchered at the beauty salon, she still tipped the beautician, didn't she? And she still went back there the next time?).
What does matter is that it sounds like it will do something ("this miracle cream reduces the appearance of fine lines due to aging"). They also learned from the cosmetics people that appearance and packaging is even more important than function: a Clairol box and bottle costs more to make than the product inside. Therefore: billet and blue-anodized.
Speed equipment is quite different. Someone invents something that works, and he discovers that he will make more money making them for 1,000 people than he could by winning races against them.
Vic Edelbrock: first the successful product, then the marketing.