etorque does more than help with starts and smooth out shifts ....

[cruz-in]

Not often talked about is etorque works to keep the truck in cylinder deactivation longer. Quoting from a forbes article:

"since most roads aren’t completely level, the engine often ends up cycling back and forth between four and eight cylinder modes. With the mild hybrid system, the BSG can give the engine enough of a boost on gentle grades to keep the engine in four cylinder mode to keep the other four cylinders shut down. "

Link to Full Article

 

[CompuDav]

Thanks for posting the article! I hadn’t read that in-depth of an explanation before. FWIW, I love the eTorque engine and just keep hoping I never have problems with it.

 

[cruz-in]

Glad you appreciated it. I too like my etorque.

 

[cruz-in]

Another thing etorque does (again quoting from the article):

"During deceleration, fuel flow to the engine is shut off more aggressively and for longer periods than it normally is on a 12V system because the BSG has enough torque to assist in turning the the engine during transients when the vehicle might transition back to acceleration "

 

[riccnick]

Not often talked about is etorque works to keep the truck in cylinder deactivation longer. Quoting from a forbes article:

"since most roads aren’t completely level, the engine often ends up cycling back and forth between four and eight cylinder modes. With the mild hybrid system, the BSG can give the engine enough of a boost on gentle grades to keep the engine in four cylinder mode to keep the other four cylinders shut down. "

Link to Full Article

Its a 16 hp motor (I think), and who knows at what rpm, and its on a reduction drive with the pulleys. Even though it puts out 130lbs-ft of torque, it's not enough to "add" power to the engine, even in 4cyl mode. And remember, electric motors put out peak torque at zero rpm. Even IF the peak torque stayed available throughout the rpm range of the mgu, 16 hp would happen at 646 rpm (it would obviously be much higher, because we know peak torque drops off as rpms increase). With the reduction drive, that means probably like 100 rpm engine speed. There's so much misinformation out there about how eTorque works, and it's understandable because it's kind of shrouded in mystery, but I'm very confident that when the engine is being used to drive the vehicle, eTorque is not "adding" or "assisting" forward motion at all. The reason it can use it's 130lbs ft to move the truck forward "1/2 tire rotation" is because its a low rpm, high torque, reduction drive application. It's not meant for driving speeds.

 

[klail]

Its a 16 hp motor (I think), and who knows at what rpm, and its on a reduction drive with the pulleys. Even though it puts out 130lbs-ft of torque, it's not enough to "add" power to the engine, even in 4cyl mode. And remember, electric motors put out peak torque at zero rpm. Even IF the peak torque stayed available throughout the rpm range of the mgu, 16 hp would happen at 646 rpm (it would obviously be much higher, because we know peak torque drops off as rpms increase). With the reduction drive, that means probably like 100 rpm engine speed. There's so much misinformation out there about how eTorque works, and it's understandable because it's kind of shrouded in mystery, but I'm very confident that when the engine is being used to drive the vehicle, eTorque is not "adding" or "assisting" forward motion at all. The reason it can use it's 130lbs ft to move the truck forward "1/2 tire rotation" is because its a low rpm, high torque, reduction drive application. It's not meant for driving speeds.

Good info! Thanks!

 

[CompuDav]

Its a 16 hp motor (I think), and who knows at what rpm, and its on a reduction drive with the pulleys. Even though it puts out 130lbs-ft of torque, it's not enough to "add" power to the engine, even in 4cyl mode. And remember, electric motors put out peak torque at zero rpm. Even IF the peak torque stayed available throughout the rpm range of the mgu, 16 hp would happen at 646 rpm (it would obviously be much higher, because we know peak torque drops off as rpms increase). With the reduction drive, that means probably like 100 rpm engine speed. There's so much misinformation out there about how eTorque works, and it's understandable because it's kind of shrouded in mystery, but I'm very confident that when the engine is being used to drive the vehicle, eTorque is not "adding" or "assisting" forward motion at all. The reason it can use it's 130lbs ft to move the truck forward "1/2 tire rotation" is because its a low rpm, high torque, reduction drive application. It's not meant for driving speeds.

But the part where the article says that the eTorque system can help the truck engine stay off longer at stop lights is accurate, right? And it does get the truck moving at least a little bit at start. Are those then the only benefits to eTorque?

 

[cruz-in]

Its a 16 hp motor (I think), and who knows at what rpm, and its on a reduction drive with the pulleys. Even though it puts out 130lbs-ft of torque, it's not enough to "add" power to the engine, even in 4cyl mode. And remember, electric motors put out peak torque at zero rpm. Even IF the peak torque stayed available throughout the rpm range of the mgu, 16 hp would happen at 646 rpm (it would obviously be much higher, because we know peak torque drops off as rpms increase). With the reduction drive, that means probably like 100 rpm engine speed. There's so much misinformation out there about how eTorque works, and it's understandable because it's kind of shrouded in mystery, but I'm very confident that when the engine is being used to drive the vehicle, eTorque is not "adding" or "assisting" forward motion at all. The reason it can use it's 130lbs ft to move the truck forward "1/2 tire rotation" is because its a low rpm, high torque, reduction drive application. It's not meant for driving speeds.

If etorque does nothing at highway speeds, why is the EPA Highway Estimate 1 MPG higher for an etorque equipped ram hemi (23 versus 22)?

 

[Edwards]

If etorque does nothing at highway speeds, why is the EPA Highway Estimate 1 MPG higher for an etorque equipped ram hemi (23 versus 22)?

You have to look at how the EPA tests highway. It's not doing 70 for half an hour. With the slower speeds and changes used in their test, eTorque helps out.

 

[riccnick]

But the part where the article says that the eTorque system can help the truck engine stay off longer at stop lights is accurate, right? And it does get the truck moving at least a little bit at start. Are those then the only benefits to eTorque?

The eTorque system consists of only a few components:
-The MGU (Motor Generator Unit) that (on a Hemi) sits where the alternator would be on the engine accessory drive circuit (serpentine belt).
-The 48V battery pack, used for storing electrical energy, located behind the rear seatback on Crew Cab models (no idea if eTorque is available on Quad Cab trucks)
-Some fans and computers used to keep the said battery pack charged and cooled.
-Literally that's it. The truck still has a normal 12v battery in the engine bay, a regular starter used for "cold" starts when the ignition is off. It's literally the same truck minus the alternator.

It operates like this:
1) Start / Stop - during a start / stop even, while in Drive only, the truck will shut down the engine, and the MGU will restart it when you lift your foot off the brake

2) Initial Roll (E-Roll Assist) - the MGU will spin the engine, and therefore the transmission and wheels while starting the motor from a start / stop even, helping to push the truck forward and make the handoff between the MGU and the Hemi seamless.

3) Regenerative Braking - nothing more than the MGU adding drag to the engine in order to generate electricity and storing it in the 48v battery pack. It does not affect the regular vehicle service brakes at all. It does ad a "compression braking" effect to the driving experience of the truck, causing it not to "coast" as far or as long. It's just acting like a really big alternator.

4) Engine Electrical Load Reduction - Using that stored electrical energy, the MGU can be "shut off" while at cruising speeds and therefore the engine will have no extra load from it acting like an alternator. In this mode, the 48v battery pack charges the 12v battery and will also directly supply power for all of the running accessories (headlights, music, Uconnect, etc). This is where the 2mpg on the highway is supposed to come in.

5) Engine Speed Matching Upshifts - the MGU can be used to scrub engine speed (further charging the 48v battery) during upshifts so that the transmission doesn't have to take the burden.

6) Engine Speed Matching Downshifts - the MGU can provide assistance to help rev the engine during downshifts in order to help seamlessly match engine speed to ground speed.

To me, there's a seventh mode too, which is when the 48v battery is already full, but the driving conditions are primed for regenerative braking or charging. In this "mode", the 48v battery will run the cooling fans at the radiator to "over-cool" the engine, and therefore allowing the stop / start cycles to last longer at a light or stop sign.

 

[cruz-in]

Video by FCA and one of their engineers discusses how etorque helps at highway speeds. Check it out at about the 2:40 point in the video.

Etorque Systems Help at highway speeds discussed at 2:40 point in this FCA video

 

[cruz-in]

Okay, so you don't want to believe a Forbes article. Here is another video of a RAM engineer explaining the etorque system assisting to keep the engine in 4 cylinder mode longer.

Go to the 2:40 Point in this video to see a RAM engineer discussing how etorque assists to keep the engine in 4 cylinder mode longer.

 

[cruz-in]

Okay, so you don't want to believe a Forbes article. Here is another video of a RAM engineer explaining the etorque system assisting to keep the engine in 4 cylinder mode longer.

Go to the 2:40 Point in this video to see a RAM engineer discussing how etorque assists to keep the engine in 4 cylinder mode longer.

At 3:40 he mentions etorque's help in 4 cylinder mode again.

 

[riccnick]

Okay, so you don't want to believe a Forbes article. Here is another video of a RAM engineer explaining the etorque system assisting to keep the engine in 4 cylinder mode longer.

Go to the 2:40 Point in this video to see a RAM engineer discussing how etorque assists to keep the engine in 4 cylinder mode longer.

I understand what you're saying, but two things:

1) I don't believe him
2) I think he misspoke, this is the only video or place I've seen it mentioned as well. There's no way they're using "the 130 foot pounds" to help stay in 4cyl mode longer. Maybe some of that torque, sure, and at a very low engine rpm, but certainly not on the highway. he even goes on to explain that the MGU is essentially acting as an alternator at 50-60 mph. It would be wildly inefficient to use the reduction drive electric motor to compensate for a V8 engine running on half of it's cylinders. IF it does in fact do that, I can't imagine it lasting for a very long time at all, not more than a couple seconds.

 

[cruz-in]

"There's so much misinformation out there about how eTorque works, "

Concur ... So is your point Forbes and two FCA Engineers are putting out misinformation?

 

[cruz-in]

I understand what you're saying, but two things:

1) I don't believe him
2) I think he misspoke, this is the only video or place I've seen it mentioned as well. There's no way they're using "the 130 foot pounds" to help stay in 4cyl mode longer. Maybe some of that torque, sure, and at a very low engine rpm, but certainly not on the highway. he even goes on to explain that the MGU is essentially acting as an alternator at 50-60 mph.

Okay I added a second video with a different RAM Engineer....don't believe him either?

 

[cruz-in]

I understand what you're saying, but two things:

1) I don't believe him
2) I think he misspoke, this is the only video or place I've seen it mentioned as well. There's no way they're using "the 130 foot pounds" to help stay in 4cyl mode longer. Maybe some of that torque, sure, and at a very low engine rpm, but certainly not on the highway. he even goes on to explain that the MGU is essentially acting as an alternator at 50-60 mph. It would be wildly inefficient to use the reduction drive electric motor to compensate for a V8 engine running on half of it's cylinders. IF it does in fact do that, I can't imagine it lasting for a very long time at all, not more than a couple seconds.

He says it again at the 3:40 point...

 

[riccnick]

Okay I added a second video with a different RAM Engineer....don't believe him either?

The first video doesn't state that at all, does it?

I watched the second one as well and that's the one I think is wrong.

at 3:40 in the second video he does not say the eTorque system adds or assists with power, he specifically says during that scenario they're using the gas motor. The second video is with Mark Williams from Pickuptrucks.com, right? Just making sure I'm on the same page with ya here.

 

[cruz-in]

Okay another video where an RAM engineer discusses the benefit of etorque at highway "steady state" speeds and how it allows 4 cylinder mode to be heed longer. This engineer even says at 70 MPH it extends cylinder deactivation. Is this RAM Engineer wrong too?

At the 7:40 minute point in this video is a RAM engineer describing getting "allot of value" from the etorque system

He even says " ..at cruising speeds that is a place where we get allot of value." and ...and anytime you are doing steadyy state cruising, at 35 MPH or 70 MPH we have the ability to extend the operation of our cylinder deactivation.."

don't believe him?....think he mispoke? "

 

[cruz-in]

So Forbes and several videos interviewing RAM engineers are all wrong. Is it your contention the RAM engineer in the last video is lying?

Seriously view the video in the last post. The RAM Engineer goes to length to explain how etorque helps at "steady state" speeds by extending 4 cylinder activation. There goes your argument rationalizing the EPA Highway improvement is because the EPA does not run at steady state.

I could post several other videos and articles describing the benefits of etorque at steady state highway speeds. However, if you contention is "I don't believe him" and "I think he misspoke" . it is pointless.