Turning off 4cyl mode on the 392?

Ben_

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Does anyone know a way to prevent cylinder deactivation? The exhaust sounds odd and I think there’s lifter issues where oil isn’t being supplied to the deactivated lifters, but they are still moving (not sure on that last part).

Anyway, can this mode be disabled? I know if you kick it into manual mode, it won’t deactivate cylinders. But then you have to click through gears.
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Livernois Motorsports

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The shameless plug solution is, if you get a PCM unlock, tuner, and bypass cable from Livernois Motorsports, we absolutely can disable it for you. Better yet, our 392 is in transit, and ready for us to start tearing into it for upgrades!
 

cpost6

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The shameless plug solution is, if you get a PCM unlock, tuner, and bypass cable from Livernois Motorsports, we absolutely can disable it for you. Better yet, our 392 is in transit, and ready for us to start tearing into it for upgrades!
PM me with your best price. Want to correct speedo and raise top speed limiter also. I see that can be done.
 

Outrun

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The shameless plug solution is, if you get a PCM unlock, tuner, and bypass cable from Livernois Motorsports, we absolutely can disable it for you. Better yet, our 392 is in transit, and ready for us to start tearing into it for upgrades!
It would be cool to be able to manually turn it on/off. Like long flat boring freeway trips to save gas.
 

MaineBumpkin

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If I use the manual gear selector and set 8th as highest in my RAM it kills the annoying VVT 'Eco' mode. Not sure it would work the same in a Wrangler 392 but worth a shot.
 

Young04

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How often do the cylinders deactivate in city/suburban driving?
 

weeitsmikelee

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Seems to activate under 1500 rpm for me.
 

Livernois Motorsports

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It would be cool to be able to manually turn it on/off. Like long flat boring freeway trips to save gas.
We can do a tune with it still enabled, but there is no "defeat button" other than using manual mode

If I use the manual gear selector and set 8th as highest in my RAM it kills the annoying VVT 'Eco' mode. Not sure it would work the same in a Wrangler 392 but worth a shot.
Same idea, manual disables it

How often do the cylinders deactivate in city/suburban driving?
It does depend on how you drive, but I have had it turn on within an intersection
 

Sean L

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Does anyone know a way to prevent cylinder deactivation? The exhaust sounds odd and I think there’s lifter issues where oil isn’t being supplied to the deactivated lifters, but they are still moving (not sure on that last part).

Anyway, can this mode be disabled? I know if you kick it into manual mode, it won’t deactivate cylinders. But then you have to click through gears.
When MDS is active the pushrod is partially disengaged, the roller is still in contact with the cam but a solenoid moves a part of the pushrod out of the way to prevent the valves from opening. Oil still gets to the moving parts as needed. My old Ram gave me no troubles and I hardly noticed any significant difference in exhaust note (although I was still stock). I can imagine a Tazer for the 392 is in the works that can prevent MDS and probably already exists for other models with Hemi engines.

Mechanically, you shouldn't be worried over the MDS.
 
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