SUPER CHIP 3815/MDS UPDATE
installed the unit yesterday on the 87oct tune.noticed alot firmer shifting as advertised.yesterdays temp dropped about 15deg and the wind picked up to about twenty mph.all that being said i still managed 19mpg avg round trip.as we all know the colder it gets the richer the burn hince more fuel used.i would love to see this thing work in the summer.unfortunately on the 07 you can't adjust the shift points.you 03-06 guys can i'm told.maybe this is something that can be updated via internet in the future for the 07 on.overall i'm very satisfied with the performance of my truck even though i thought my 03 5.7 ran great too.after this tank i'm going to the 91oct tune and take it down to Procharger for a dyno pull.just as a side note todays weather here in k.c. is overcast and 49deg.i'll post an update on mpg tomorrow.

 

Hello Ram owners... 07 Durango owner here with 5.7 Hemi. I too put on a single in dual out magnaflow on my durango about a week ago and the rpm fluctuation is about to drive me nuts. My muffler is 3 ' in and 2.25' outs. They said they had to use 2.25 outs because of the bends and clearance they needed. I was wondering if this would change any performance if they would have been 2.5' outs.

When I a set my cruise at 70... my rpms fluctuate from 1900 rpm to 2100 rpm constantly.

You all have talked about the PCM reset ... will the same steps apply for that in a Durango?
Also, takin it out of OD... would that be pressing the tow/haul option on my shifter? When I press that button it makes my rpm sky rocket.
AND... Has it been confirmed yet that your rpms will RISE when you are in MDS mode or should they drop? There seems to be differing views on what actually constitutes that your motor is in MDS mode. I wish there was some type of add on that had an indicator light which told you that you were in MDS mode or not. Please advise on what I should do for my situation.

 

Im starting to see some differences in these systems(mds)...some of you are having different results than others. Makes me curious ifmine is working properly or is mine fine and others not. This is a mystery.

 

This shouldnt be a mystery. Rpms will always be higher when MDS is operating, thus to reduce load and detonation. When cruising consistantly at a certain speed, you should see rpm increase about 200 rpm.. As for low speed operation and mds engaging, it is normal, as anything 7-15% throttle or below will allow it. This is perfectly normal. I have had three Dodges with MDS so far and all have behaved this way. One of those was even a charger. This will not hurt anything, I think observations of rpm lowering during MDS operation are simply backwards(I dont mean to sound mean, but I am just trying to get this sorted out). Do not worry about this. Your truck is normal. It is just easier to hear and notice the switch between the two modes with aftermarket exhausts.

As said, the pcm reset for MDS operation seems incorrect. Not enough backpressure is lost to greatly reduce torque. Of course do the reset to benefit form mods by pulling fuse 11 I believe, but not to aid MDS.

All and all, this is just how it operates. To be honest, its not so "seemlessly and smooth operating" as Chrysler says, but it works.Drive the hell out of it and don't worry, unless the truck is bucking violently.

 

I've always seen my rpms drop when mds kicks in. Can definitely hear it in the exhaust with the cutout, and the rpms drop about 100-200. I actually tested it out today. The only other possibility for the rpm drop I can think of is the torque converter locking/unlocking at the same time mds is changing modes, but it does it every time.

 

I have to agree with Hemiboss. On the way to work I set cruise at 65mph. I watched the rpms go from 1750 (OD) to 1950 (MDS). I reset the computer mpg and watched it climb to 18.9...... I came to an overpass and watched the rpms actually go back down to 1750 (OD) when I started up the hill. The mpg went down to 18.5.... On the way down the hill the rpms went back up to 1950 (MDS) and the mpg started climbing back to 18.9....

At 70mph had a hard time kicking in and out of MDS. An indication option sure would be nice.

 

I am beta testing the Edge Products programmer for the 07. It shows when your in V8 or V4 mode. I can confirm what Hemiboss and ericflesser have said about the MDS and RPM's. With an aftermarket exhaust your going to notice the MDS a lot more, ie noise and shifting. Get use to it. Its OK. or return to stock untill something else comes out to deal with it.

 

hi pappy i run mine on 87 and get better gas mileage than 89 .......thats because it sounds meaner w/89 and i beat it up more. new dual out w/ side outlet flowmaster

 

Hemiboss and the rest of you guys...i really appreciate your advise and Im glad to hear my truck is normal. Im just nervous in that i want things perfect i guess. We paid alot of money for these trucks...I would hope they work like they should. I will quit complaining about it now that I know its normal.

 

I still complain about it and I know it is normal!! Ha!! In reality it isnt really that bad. I am the one who wanted the aftermarket exhaust so I will have to live with it. The Daiblo tuner when it comes out will have the ability to disable MDS, that is one the of the main reasons I plan to buy it. During the week 80 miles a day to work, MDS on, on the weekend out goofing off, MDS gone.