Yesterday i was messing around with my superchip, i disabled MDS and switched from 91performance, to 87... And raised my rpms to 5800 from 1st to second ....WOW...

I had taked a 200 mile trip on a highway going and coming my MPG went up to 18-19.5 the whole way..Also my throttle reasponse was significantly faster then before. Anyone know why this is....
I recommend Disable your MDS...

 

the increase in mpg may have just been because of a tailwind. you will get snappier throttle at highway cruising because the 8 cylinders are already on instead of down to 4. but unless there is some strange condition, your mpg shouldn't be better without MDS.

as an engineer, MDS hardly makes any sense to me. Yes you can avoid putting fuel in thsoe cylinders, but you have to put in more fuel in the other 4 to keep making power to keep the truck moving. the only thing you save is the frictional loss from air moving into and out of the dead cylinders...energy equivalent to a leaf blower as i've recently discovered

 

but even when i am driving around town and give it my truck down shifts quicker and it has a lil bigger kick to it then usual. Maybe it just went to my head.. lol But the highway going and coming gave me alot better mpg...

 

When I had my superchips it was fun having it on 87 running 89 becuase around town it felt like it had a lot more torque to it with that tune, however, on the highway while the throttle responce was still there, the truck did not pull as hard as with the 91 tune. Also 0-60 times were faster with the 91 vs the 87.... If you really want a snappy throttle look into getting a ported TB you'd love it!!

 

think msd would be better if it ran off 6 rather than 4?

i agree about the 91 tune, the tow/haul works well too i think.

 

doubt it. for the same reason it doesn't do wonderful things running off of 4, the rings are still going up and down and the rod is still going around and around, all frictional losses that are greater than the friction losses with air that you save. also, i bet balancing an 8 running on 6 isn't fun at all.

 

I agree with you there truckin, i am running the 87 tune with 91 octane.. And i feel an improvment while crusing..BUt i havent ran MDS off on 91 tune so maybe that would be a better route to follow, but for now this is a good setting for me...

PORTED THROTTLE BODY..... can you get me some info on this....

 

This is where I got mine from

http://www.thefastman.com/

The site does not have an option for the 5.7 but he will di them and does a great job getting them done and to you very quickly, also helps you and gives great support if anything should go wrong with the setup.

My experience with the Knife edge
https://dodgeforum.com/forum/3rd-gen...e-goodies.html

My experience with the non-Knife edge.
https://dodgeforum.com/forum/3rd-gen...ported-tb.html

 

Thanks Truckin really helpful treads i just finished reading up on them... I just emailed Dan (TheFastMan) so lets see what he says...

Also I did a 1/4 mile run today with my new setting on my SC 87 tune MDS OFF, and i did a 15.6, and my last best time i belive was 15.31 on 91 tune 1/4 mile time... just thought id run it out to you guys.

 

i can say a fastman tb is a great mod i havent got one for this ram but i had one on my last one and its well worth the flow....im glad i stopped in to read this thread as i am playing with tunes also good stuff i am switching to the 91 perf tune today and gonna see how i like it.....