Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec Best place to get Mondeo ST220 UIM & LIM?

Yeah, there is an advantage to the 3L oval plenum being a bit larger and also a shorter, more straight shot into the manifold but that again may only manifest as a benefit in certain operational rpm ranges.
All I can say is the dual runner hasn't proven to be a restriction, has proven to provide a wider/flatter curve on the basic production motor, and similar on 3L hybrids.
As for FI, I ran it and it was not apparent to me that there was any significant restriction from it for FI. With the secondaries still working it did restrict airflow below IMRC (obviously) with the turbo and that did reduce some of the potential torque around the 3000+ to 3800rpm where the IMRC opened. However, below that it did not impact it and above that it did not.
THis was a benefit in that it allowed traction, but then the sudden onset of power with IMRC open point would easily break traction. It was a moot point for racing type driving because I could and did launch so quickly that IMRC wasn't a noticeable issue, but if I were driving normally, it enabled the car to run very nice, stock-like and with good economy of fuel. Best of both worlds I think.