HEMI MDS questions

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Tincup

Tincup

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After talking with Chris at Hotwire, I found out that my MDS will not work. It seams that because I have the truck tranny, he supplied me a truck computer that does not support MDS (05). He also said that the diablosport tuner does not work on 06 up computers ( I don't get that ). My question is, is there any way to hot wire the MDS to turn on/off with a switch?
 
How could an '05 truck ECM not support MDS? That was the first year for MDS on the Ram...if he had provided you with an '03 or an '04 ECM it would make sense but not for '05....
 
xlexl said:
How could an '05 truck ECM not support MDS? That was the first year for MDS on the Ram...if he had provided you with an '03 or an '04 ECM it would make sense but not for '05....
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The first year for MDS on a Ram was 06.
 
Tincup said:
The first year for MDS on a Ram was 06.
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Wow not sure where I had gotten that information, I remember when I had my '04 (pre-stolen sawzall hack job) I was doing research and for some reason had run across enough that I came to the conclusion that '05 came with it... you inspired me to recheck information, and it appears that I was grossly mistaken, I appologize, I seem to have added to the notion that the first post is always an idiot lol.
 
Tincup said:
After talking with Chris at Hotwire, I found out that my MDS will not work. It seams that because I have the truck tranny, he supplied me a truck computer that does not support MDS (05). He also said that the diablosport tuner does not work on 06 up computers ( I don't get that ). My question is, is there any way to hot wire the MDS to turn on/off with a switch?
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UMMM what??? I have a Diablo tuner on my 2007 R/T charger, best 300 bucks you can spend, they work to the best of my knowledge on ALL hemi's regardless of year so he is FOC IMO.
 
I would think you could operate the solenoids easily enough with a toggle switch, but shutting off everything else associated with the system might be hard. You'd have to cut the fuel injectors too if you're not running a carb at the least as well as the coils. Not sure what else is tied into the system. I have read there are a ton of parameters associated with turning it on and off in the computer, but not sure how many of them really matter (oil pressure, oil temp, rpm, wheel speed, etc.).
 
my superchips programmer works great on my 08 Ram, including enabling/disabling MDS.
 
I have a Diablosport U-7135 tuner for my 09 Challenger, it works great. Is yours an older model?
 
Diablo isnt as friendly for the trucks as it is the cars.
Theres no switch you can add to easily enable/disable it...the best/only way is through your programmer.
I too have Diablo on my car (MagnumRT) but chose SCT for the truck (04 Ram)...its alot less finickey.

And yes, 06 is the first year for MDS on the trucks. 05 was for the cars (all of em had MDS)
 
I talked with Chris this afternoon, and the MDS won't work with a switch due to not being able to shut off the fuel. The Diablo problem is for hot rods only, the 06 computer need additional inputs that the 05 does not, so it dosen't make sense to use them.
 
ok back up. The dablo will work on the 06 and up rams. And does work really well. Only the 1500's have mds with the exception of the mega cab witch Is really a 2500 with a few slight tweeks that I'm not 100% sure on. The 06+ pcm might not support mds in any hot rod application as there are about a dozen peramiters that need to be met. Some of witch require the body control module if I'm not mistaken.

now lets see what your asking here. I assume you have an mds motor correct? I also assume your wating to keep mds functional. I have to ask why? Ican only assume it's for fuel economy. I had an 04 hemi and now own an 06 both being ram 4 door trucks. Both are 1500's and I can tell you mds is garbage. The hype wants you to believe it is 100% seamless. And that it's not noticeable. Well it's a load of BS. I notice it. I can tell when it's in mds and it's sluggish to transition outof mds. There is no real fuel savings. I had heads and cam and every possible bolt on under the sun with my 04. I averaged 16mpg calculated baised off miles driven and gas consumed. My 06 gets 17.5mpg. So your able to go awhopping 150 miles further on 100 gallons of gas. Or aprox 30 miles on a 20 gal tank. To me it's not really a savings at all. That's not even 1 trip to work for me. So who cares. Don't believe the hype. It's not all it's cracked up to be.

on that note I feel for you that you were lied to about what you got. But I think it's really a blessing in disguise. Hope that shed some light on the subject.
 
I absolutely love the MDS on my Challenger, as I take a LOT of long trips. I have gotten as high as 28.5 mpg on those trips with a 4100 lb. car that will click off a high 13 with the trunk and gas tank fully loaded.
 
the problem with comparing the cars is that the pcm is different. The weight of the car is different ect. The ram pcm will not behave like the car pcm. There are too many diffrences. And you drop the hemi in a 3000 pound car (ie an a body) vs a 4000 pound car or 5000 pound truck and your going to get way better fuel milage. (assuming the driving style doesn't change) because the motor has so much less work to do to maintain speed. And a non mds hemi will probably see 25mpg at a cruising speed going donw the highway.
 
adamsredlines said:
They certainly support them but their truck tuning is certainly not without issue.
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it's mass produced it will have issues. The cars have issues too. Granted not as many, because the aftermarket is better for the cars (ie more people mod cars than trucks) diablo is not always at fault though the 03 pcm is uique to 03 and the 04 trans controls have not been nor will they be cracked by diablo. (they gave up on the 04's) the 05 and up have full cotrol.
 
Having issues is one thing, killing PCMs and such is another. Its more than just the 03 PCMs also, they seem to have issues throughout the years...its hit and miss.
 
Hello,

If I am not mistaken all 4 MDS soleniods are pulse width modulated rather than straight 12 volts on to keep the sols cool while operating. You will simply burn them out. Also you have no way of shutting off all for injectors unless you switch them also and timing that would be critical. Spark occurs all the time so that does not matter. For an install into a muscle car , it porbally is not worth the work to get it operational. All of the inputs/ outputs have to be operational and most inportantly the BUSS has to be functional also. with out a VSS signal it will never work.
ALSO if you want the MDS to operate 5-20 only. I have seen cases where 5-30 will shut it down

All of the orginal doner electronics have to installed probally, too much work for a small gain.
 
My 05 Magnum RT had the MDS, and it worked reasonably well, my only complaint was the added drone through the Magnaflow exhaust. Don't misunderstand me, my motor has the setup so it would have been nice to use it. If for some reason I didn't like it, I could always shut it off with the Diablo. I plan on driving my car to a number of shows in NY and PA, so why not take advantage of a system my motor already has. I would not spend a ton of money to get it, but if it worked, why not use it.....
 
Also another very important tip.

If the motor has been sitting for a long time or you have had the oil pump off, make sure you fill the pump with assy lube. Most of the times these pumps will not self prime and you can have engine damage before you know what has happened.
 
HemiEd said:
I absolutely love the MDS on my Challenger, as I take a LOT of long trips. I have gotten as high as 28.5 mpg on those trips with a 4100 lb. car that will click off a high 13 with the trunk and gas tank fully loaded.
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X2 here I get 30 mpg's with the mds ON, off holy crap can you say suck gas???? and the transition is not noticiable when I am not using the diablo tune, but it is noticable(slightly) when the 91 tune is in, but is sure doesn't bother you, IMO only thing that leads me to beleve anyone that says mds is crap, might be do to it being on a truck, I have not driven a truck with mds, so maybe for that it is crap, but that is the only way to go on a car IMO. I have heard they are gonna put them on the 6.1 AND the 6.4 not sure about the 6.4 but I know they are going/or are doing it for the 6.1's
 
I hated MDS on my Magnum, felt like the trans was slipping or pulsing. I thought something was screwed up because everyone says its not something you can feel but i disagree completely. Got my Diablo, turned it off...no more twitch.

The best i averaged on a long trip was 23.5 MPG w/ MDS. With it off, i got 22...
maybe they made it more seamless later on as my Magnum is an 05 but i say good ridance to it.
 
adamsredlines said:
I hated MDS on my Magnum, felt like the trans was slipping or pulsing. I thought something was screwed up because everyone says its not something you can feel but i disagree completely. Got my Diablo, turned it off...no more twitch.

The best i averaged on a long trip was 23.5 MPG w/ MDS. With it off, i got 22...
maybe they made it more seamless later on as my Magnum is an 05 but i say good ridance to it.
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did you update your tuner over the internet? they release a new tune practicly every other month, you need a serial cable and power pack to do it, I have a 2007 RT so maybe they did make some mod to the mds. If you haven't updated your diablo you should, it makes a big difference IMO.
 
My diablo is updated to the most recent one for 05s that still retains EGR delete. Diablo said all the croms after that were for newer model years and would cause an issue on the 05 (lose a few options because of PCM differences).
 
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