Challenger Video on MSN.com

[BobF's 6POINT1]

Nice 5 minute walk-through

http://video.msn.com/v/us/v.htm

[Cam]

That's it, they make it, I buy it. Nice find.

[rossb]

The dude in the video said the 6.1L SRT motor in the car has MDS.

[shiltz]

That would be really nice if it's true, that's the one thing that really anoys me about the current SRT-8's, they have the wonderfull MDS system which has no impact on perfomance and give a nice boost in fuel economy and then they they don't use it on the 6.1 so it gets poor fuel economy, a 6.1 with MDS and say 15 city / 21-22 highway would be great.

[bradkaye]

The MDS would be great on the 6.1. With the extra power of that engine the MDS would be able to stay engaged more often, potentially even beating R/T highway mileage. That could be a win/win... WIN.

Also, the MDS would benefit from having a 2nd smaller exhaust valve per cylinder, pneumatically actuated by the computer that opens to the exhaust manifold when MDS is engaged on that cylinder.

Saving the energy that it takes to compress those 4 off-duty cylinders to 9.3/1 compression, I'm sure would push the efficiency margin of the MDS beyond 20%.

[shiltz]

Well unfortunatly it wouldn't actualy work that way since at 65mph it only takes something like 40-50hp to maintain that speed so the extra hp would just be wasted, I belive the only reason it drops out of 4 cylinder mode when not accelrating is because the cylinder is starting to cool down and it needs to heat it back up, but either way it would still be much better than the current SRT-8, that's for sure.

[bradkaye]

Well unfortunatly it wouldn't actualy work that way since at 65mph it only takes something like 40-50hp to maintain that speed so the extra hp would just be wasted, I belive the only reason it drops out of 4 cylinder mode when not accelrating is because the cylinder is starting to cool down and it needs to heat it back up, but either way it would still be much better than the current SRT-8, that's for sure.
Actually, it kicks into MDS when the engine is below 30% load and falls back out of MDS when the engine hits 40% load. The load at any given RPM would be less if the engine had more HP & Torque, letting the MDS stay engaged longer. I have the ScanGauge (http://scanguage.com/) in my car, so I know exactly when it comes in and out and why.

As for it kicking out due to issues of cool down, it cycles out for a moment then back on, not the same as when you simply can't hold the MDS activated on a slight grade at 70mph. If this were a huge issue, they could program in alternating sets of 4 cylinders to be deactivated as to keep the entire block up to the relative same temperature.

The SRT 6.1 would be a ~212hp 4-cylinder with MDS on vs the ~170hp on our R/T's. Those additional ~42hp would go a bit further to keep that MDS on and in a fuel savings mode when, and if, you're able to keep your foot off the floorboard. (obviously, we're not actually talking about 212hp, that's the engine's peak, but whatever hp you've got available to you around 2100-2700 rpms when you're cruising in 5th gear)

course, i'm just speculatin on a hypothesis. i know i don't know nuthin from nuthin.