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Mudgey · 03-04-2013, 02:11 PM

Hey guys, I have been doing some researching about cylinder deactivation, displacement on demand or AFM... however you want to name it.

Engine: Honda K20a with VTEC and VCT on intake cam (iVTEC), stock form they are 200bhp, and with my supercharger it is 305bhp.

My quest is to get as best FE as I can out of the car, they do a 2ltr version of this engine in the accord that gets just under 50mpg (UK) and I am considering these mods:

1. Regrind of cams to same spec as economy cam, but keeping the K20's agressive VTEC lobe for high rpm fun. The economy cam essentially runs the engine in 12v mode with the other valve opening very minutely to stop fuel puddling. This creates swirl and concentrates the fuel droplets towards the spark plug making it richer there but overall it allows the car to run at AFR's as high as 20:1.

2. Run displacement on demand by regrinding the VTEC cams so they are flat, this would allow me to run only 2 cylinders at highway speeds, unfortunately I will lose top end torque, but this could be made up for by using a big rotrex blower with its massive ramp up of boost to help overcome the restriction at the top head.

3. Combine the above two with the reground economy cam, but use a custom made butterfly valve just infront of the injectors on the cylinders I wish to close off, by now allowing any intake charge into the engine I should still be able to take advantage of the 'spring' effect that GM use on their V8's.

Has anybody tested anything similar? What are your thoughts on the above?

03-04-2013, 02:11 PM	#1 (permalink)
Mudgey EcoModding Lurker Join Date: Mar 2013 Location: UK Posts: 12 Thanks: 0 Thanked 0 Times in 0 Posts	Cylinder Deactivation Hey guys, I have been doing some researching about cylinder deactivation, displacement on demand or AFM... however you want to name it. Engine: Honda K20a with VTEC and VCT on intake cam (iVTEC), stock form they are 200bhp, and with my supercharger it is 305bhp. My quest is to get as best FE as I can out of the car, they do a 2ltr version of this engine in the accord that gets just under 50mpg (UK) and I am considering these mods: 1. Regrind of cams to same spec as economy cam, but keeping the K20's agressive VTEC lobe for high rpm fun. The economy cam essentially runs the engine in 12v mode with the other valve opening very minutely to stop fuel puddling. This creates swirl and concentrates the fuel droplets towards the spark plug making it richer there but overall it allows the car to run at AFR's as high as 20:1. 2. Run displacement on demand by regrinding the VTEC cams so they are flat, this would allow me to run only 2 cylinders at highway speeds, unfortunately I will lose top end torque, but this could be made up for by using a big rotrex blower with its massive ramp up of boost to help overcome the restriction at the top head. 3. Combine the above two with the reground economy cam, but use a custom made butterfly valve just infront of the injectors on the cylinders I wish to close off, by now allowing any intake charge into the engine I should still be able to take advantage of the 'spring' effect that GM use on their V8's. Has anybody tested anything similar? What are your thoughts on the above?