HULKGREEN

As much as I have tried to help ..............

I just don't know the answer to that one .......... Not in the JK !!

PROLLY ............. WICKED FAST !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! lol

LuffMarine

the MDS or Multi-Displacement System on the 5.7L hemi automatically makes the engine fire on only 4 cyl instead of all 8 when ur not mashing the petal to the floor. if it acctually works then it may accually pay 4 itself in the life of the car with the difference in gas mileage, but depends on ur driving habits --- the MDS wont run 4 cyl unless u keep a steady pressure on the petal, not stop and go traffic.
http://www.theautochannel.com/news/2...20/004504.html

RevyJKU08

THAT IS INCORRECT....MDS does not kick in till you reach speeds of around 25mph with granny starts....babying the gas. You are always running on all 8 cylinders when you idle or sit in traffic. Once you hit speeds of approx. +25MPH up to approx 85 mph MDS will kick in to 4 cylinder mode if you are gentle on the gas pedal.

The only time it will kick out of 4 cylinder mode between 25 & 85 mph speeds is when you get on the go pedal or are starting an incline and you need more juice to get up a hill then it will deactivate and shift to 8 cylinder mode. Once you reach speeds over 85 mph the MDS will disable and kick into all 8 cylinders. Did some testing on my 5.7L and as well noted these speeds with my MDS indicator light that I self installed.

kntr

I talked with AEV and they do the 5.7 MDS.

RevyJKU08

Which 5.7L HEMI MDS?

340HP/390lb ft - 300C, Magnum, Charger?? or

350HP/390lb ft - Daytona Charger?? or

335HP/370lb ft - Durango??? or

345HP/375lb ft - out of the Ram Truck?? Or

330HP/375lb ft - out of the Jeep vehicles??

kntr

I got this from AEV.

"The engines are all the same, its the cal and the intake/exhaust that are different. So...we use the Ram manifolds and the WK/XK calibration, probably somewhere in between the 330 and 345"

souprdawg

I recently had a 6.1 put in my 07 Rubicon Unlimited. Screamin Lizard in TX did the swap and absolutely did a fantastic job. First of all.... if your going to drop 20-24k to get power in your ride then go for the 6.1. The weight is not much more on the 6.1 and it fits very well under the hood and looks factory as can be. I have stock D44 with 35" Toyo's and my mileage is avg. 13.5-14.0 .... not that it's any big deal. My mileage before with the mini-van motor and my 35" with auto was at most 1 mpg higher. HMMMMM 200hp at 14.5 mpg vs. 440hp at 13.5 mpg.....pretty darn good. I can't wip the damn smile off my face everytime I crank it and drive it.
Bottom line....if your going to invest more $ and juice up your JK....you will never regret going with the 6.1. I am sure the 5.7 is a great option as well but the 6.1 is everything it's cracked up to be and way more.
On the Hemi Conversion thread I will be posting a pic stream in a couple of days from start to finish on my build for anyone interested.

Go on...just do it!!!!

cormac827

daaaamn.....i couldnt imagine having a 6.1.....spending that much money boggles my mind, although if i had it i cant say i wouldnt do it .....ive driven 5.7's and they are amazing, very nice power and smooth, doing 90 and feels like youre going 40. and thats why i got pulled over by the navajo nation coppers....



.they dont like us new yorkers, let me tell you!....holy shit.