OK, found a pretty conclusive counter to Ecotek's claims:
http://homepage.ntlworld.com/cains1/Fuel_saving_ecotek.htm. He soundly argues why the valve doesnt, no CANT, do what it claims. He also points out the problems of relying on adecdotal/unscientific claims from drivers
http://homepage.ntlworld.com/cains1/Fuel_saving.htm. (also check the links at the bottom of the page for the run down on other performance addons)
Ecotek site claims the improvements come from increased turbulence, yet the patent on the device describs it as an air bleed value to alter air/fuel ratio. Bit strange dont you think?
Consider this. Its established that increasing the turbulence improves the combustion due to better mixing of the air and fuel. Yet a Racer will spend ?'00 on port polishing that does exactly the opposite, smoothing the flow of the air to the cylinder. Once there, there is plenty of turbulence introduced when the mixture goes over the valves. This article
http://homepage.ntlworld.com/cains1/Fuel_saving_turbulence.htm also points out the angle of entry is desgined to do this and shows a simulation of the airflow where bleed valves operate.
Consider also that a manufacturer spends millions developing the engine for a acceptable economy/performance balance (depending on the target market and regulations). How much does a replacement ECU cost? Yet Ecotek reckon their little ?50 valve makes all that research and technology redundant. They only own a patent on the *design* of their value, not the air bleed valve idea, so why dont the manufacturers fit them?
Then, if you read their FAQ's they admit that ECU controlled engines will adjust to compensate, so the only benefit is the alledged turblence effects.
Lastly, can you remeber seeing an advert for one? No? Thats because all their claims (except being "new") where soundly arse kicked by Advertising Standards:
http://www.asa.org.uk/adjudications/show_adjudication.asp?adjudication_id=37807. So they basically cant advertise and have to rely on a few planted editorial stories.
To be fair, it seems to me that you will see some improvements to throttle responce, but you'd get the same effect by rigging your throttle to to remain open a little more than it should be at idle. You'd also see a bit of improved fuel consumption on a carbed engine (and probably K-jet too) due to the leaner mixture.
sorry to go on, but i dont like scams.
