Factory Flash to remove MDS
#41
11-01-2007, 10:36 AM
RE: Factory Flash to remove MDS
ORIGINAL: HankL
There is a past post out there somewhere
where a Magnum 5.7 MDS owner with an aftermarket
"ScanGauge" studied what engine conditions were necessary for MDS to engage, and if memory serves me right
he posted that the PCM computer needed a minimum oil pressure (maybe 40 psi?) and that by 'hacking' the oil pressure sensor with a resistor similar to the old IAT hack it was possible to keep the MDS from engaging.
Don't take this as a recommendation that MDS should be removed, or that it is somehow bad, or that skilled re-programmers can't make MDS and high performance modifications work together....all of that is false.
What MDS does is give the typical owner about half the MPG improvement he would get if his transmission, diff and tires all had the optimum ratio for part-throttle highway cruise.
If MDS gives you a 2 MPG boost at 70 mph....you could get a 4 MPG boost if the drivetrain ratios were optimum...but with the optimum ratios you have to downshift to pass vehicles or climb steep hills.
It is worth noting that CVT gives optimum MPG, and Chrysler admits this by purchasing CVTs from the Jatco division of Nissan....but the CVT can't give instant power as quickly as MDS can.
The double drive shaft DirectShift manual transmission developed by the USA company Borg Warner for Volkswagon gives nearly instant power shifts...but they always have a jerk.
Chrysler announced last year they were developing a trans similar to the DirectShift.
The multi-mode transmission jointly developed by Chrysler/GM/BMW has other tricks to give nearly instant power boosts to engines that were cruising at part-throttle
There is a past post out there somewhere
where a Magnum 5.7 MDS owner with an aftermarket
"ScanGauge" studied what engine conditions were necessary for MDS to engage, and if memory serves me right
he posted that the PCM computer needed a minimum oil pressure (maybe 40 psi?) and that by 'hacking' the oil pressure sensor with a resistor similar to the old IAT hack it was possible to keep the MDS from engaging.
Don't take this as a recommendation that MDS should be removed, or that it is somehow bad, or that skilled re-programmers can't make MDS and high performance modifications work together....all of that is false.
What MDS does is give the typical owner about half the MPG improvement he would get if his transmission, diff and tires all had the optimum ratio for part-throttle highway cruise.
If MDS gives you a 2 MPG boost at 70 mph....you could get a 4 MPG boost if the drivetrain ratios were optimum...but with the optimum ratios you have to downshift to pass vehicles or climb steep hills.
It is worth noting that CVT gives optimum MPG, and Chrysler admits this by purchasing CVTs from the Jatco division of Nissan....but the CVT can't give instant power as quickly as MDS can.
The double drive shaft DirectShift manual transmission developed by the USA company Borg Warner for Volkswagon gives nearly instant power shifts...but they always have a jerk.
Chrysler announced last year they were developing a trans similar to the DirectShift.
The multi-mode transmission jointly developed by Chrysler/GM/BMW has other tricks to give nearly instant power boosts to engines that were cruising at part-throttle
I'll tell you what, that Mercedes Transmission that they put in the Dodge Nitro R/T's will full electronic shifting is awesome. I test drove one a couple of times, and every time under every condition the second you touched the throttle, the power was to the wheels, always in the right gear, never downshifting or jerking.
I'm still not convinced with CVT's, They are OK in light cars, but I don't think they belong in Heavy trucks/suv's. CVT's have been around for a very long time in the snow mobile industry, and more recently in the ATV industry. But I speak from experience, when you put them under load, the fail every time. With a gear transmission, When you put power down, it transfers that power to the wheels, if there is not enough traction, the wheels will slip, Somethings got to give... Well on a CVT what gives is the drive belt, If you tires have alot of traction, instead of the tires slipping, the belt will slip and burn up the belt/pullies.
-ThaChad
#42
11-01-2007, 02:42 PM
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RE: Factory Flash to remove MDS
sure you truck has the weight ratiing you said
"Gross Vehicle Weight Rating (GVWR) - Standard [lb]
8510"
But as it says gross, thats full fuel, full payload, so your truck is actually closer to 6k
Ive had cars in the past with CAI and such, and yes you can feel the difference. Granted its not cheap, but if you want it, you gotta pay for it. Turbos and supercharging is always an option, and if you can justify the cost, then go for it, otherwise be happy, lol.
"Gross Vehicle Weight Rating (GVWR) - Standard [lb]
8510"
But as it says gross, thats full fuel, full payload, so your truck is actually closer to 6k
Ive had cars in the past with CAI and such, and yes you can feel the difference. Granted its not cheap, but if you want it, you gotta pay for it. Turbos and supercharging is always an option, and if you can justify the cost, then go for it, otherwise be happy, lol.
#43
11-02-2007, 05:01 AM
RE: Factory Flash to remove MDS
I am also a skeptic about high torque CVT reliability.
I would not personally buy one for a pickup truck unless
a company like UPS or Federal Express had tested them successfully
for a 2-3 year trial period in package delivery vans.
I would rather have a DirectShift style manual transmission
with 7 or 8 speeds,
and the option for computer control
when you don't feel like manual shifting.
I would not personally buy one for a pickup truck unless
a company like UPS or Federal Express had tested them successfully
for a 2-3 year trial period in package delivery vans.
I would rather have a DirectShift style manual transmission
with 7 or 8 speeds,
and the option for computer control
when you don't feel like manual shifting.
#44
01-22-2008, 12:07 PM
RE: Factory Flash to remove MDS
what year do you have? ,,,mines an 08 ,,i had a 04 i loved the way it drove ,this 08 shift thing is annoying i feel like im driving a klunker........ whats the difference between my 04 1500 slt ,tow pack.quad,hemi & this new 08 1500 big horn,tow pack. quad hemi ...???? i know i hate all this electric .computer stuff on it,but whats the difference w/ muffler ,engine ECT... why is the n08 shifty sputterry????? 04 did'nt do it?
#45
01-22-2008, 12:19 PM
RE: Factory Flash to remove MDS
does your truck idle at high 1500-2000 rpms at starting ?? if so how long till they come down ??? reason i ask is i have a 08 1500 hemi ,, and at start it idles high too high and i nfeel it takes too lng to idle down ,,,, i usually end up just putting it in drive and go on my way (then the come down)but even after driving for 30 min or longer you can shut it off and when you restart right away it does it again ,,,, my husband went outside 1 day and started the truck ,i was in the house and i was thinking he was out there revvingthe engine ===== nhis foot never was on the gas???? sounds shi**y!!!!! my 04 never did this even when cold out
#46
01-22-2008, 03:26 PM
RE: Factory Flash to remove MDS
ORIGINAL: tdmopar59
alright guys thats enough of that this is a dodge forum not a ***** forum
alright guys thats enough of that this is a dodge forum not a ***** forum
I can't believe there really is such thing!
