Intake Runner length??
 

Long runners are good for low RPM power, short runners are good for high RPM; or so I've read. My Focus has a vacuum activated intake runner controller, presumably to maximize low and high RPM power instead of compromising. Would wiring the control arm in either position give me a boost in MPG?

It might help if you could detect which position is is in and try to keep it in the long runner position as much as possible.

regards
mech

And chances are great you'll feel a HUGE difference in drivability, and not in a good way.

Thanks guys but I misunderstood my equipment. Turns out that the 2.0 engines came with "tumble flaps" and not adjustable length runners. The 2.3 engines got both the tumble flaps and the runner control. Gotta love the internet for adding to the confusion by everyone using the same name for similar, but different, equipment. Apparently the tumble flaps are an emissions and driveability mechanism, swirling the air and directing it a certain way for a more complete burn. Seems they can be removed but it hurts low end and really needs a tune to compensate.

My intrepid had 2 tuning valves in the intake, played with them a couple times and never noticed any difference in mileage, power above 4k rpm was lacking and above 6k it would barely accelerate.

A previous posting on this topic:

http://ecomodder.com/forum/showthrea...tml#post279769

I was gonna say, I thought the SVT was the only Focus with a variable intake setup...

Acura 2.0 has variable intake and you can really feel when the short side kicks in (wot), eco driving, can't feel any difference.