Ask the Engineer LIVE Chat - THIS IS THE PLACE!!

[Steve St.Laurent]

From tommike1 11-13-2009 05:56 AM



Does the regeneration process for environmental purposes create a possible fire hazard if you are driving off road in a dry grassy area? If so how could we correct this other than not driving off the paved highway?

 

[Tylerp]

Will the new V8 now in developement be capable of easy overhaul as the current engines are?

 

[amsoilman]

It would seem to me that if one were to get one of the 2010 6. 7L diesels, it would be better to use it for HEAVY DUTY work, rather than a go-t0-the-store vehicle. What are your thought on this?



Wayne

 

[blacksheepdiesel]

Ram engineer dudes, thanks for hanging with us tonight!

Would be great to see an air ride system from the factory. I have an aftermarket kit on my 2004 3500 and it improves the ride dramatically. Is the possibility good that we could see this?

Godspeed,
Trent

 

[Steve St.Laurent]

From wgood 11-13-2009 09:09 PM



Gcwr



TDR Issue 64, p. 62 says:



"GCWR has increased to 25,400 lbs. (up from 24,000 lbs. ) on 3500 DRW models equipped with an automatic transmission and the 4. 10 rear axle. GCWR has increased to 24,000 lbs. (up from 23,000 lbs. ) on 3500 two-wheel drive models. "



This statement is confusing. It seems to be comparing apples and oranges.



Is it saying that 4 WD models (not mentioned in the above statement) have a GCWR of 25,400 while similarly equipped 2WD models only have a GCWR of 24,000? Why would that be when the 4WD model weighs more than the 2 WD model. Prior to 2010 models I don't think there has been a different GCWR for 2 WD and 4 WD models.



OR... ... is it supposed to say that models equipped with a 3. 73 rear axle (also not mentioned in the statement) have a lower GCWR than those with 4. 10.



OR..... no mention is made regarding the effect on GCWR of having the G56 manual transmission instead of the automatic. Is this really the issue that was supposed to be addressed?



Please review the statement and provide clarification. Is it an error or oversight by TDR, or is it something the engineers need to explain?



Bill

 

[CumminsEngineers]

Hello, with the switch to urea instead of the regeneration do you expect to see an increase in fuel economy?

Cummins will not use the urea system on the MY2010 RAM pickup. The overall operating costs will need to be considered with a vehicle equipped with a urea system. Not only will there be the fuel purchase, but also the Diesel Exhaust Fluid (DEF). With this consideration, Cummins is not convinced that the urea system will be significantly better in fuel economy compared to the NAC (NOx Absorber Catalyst) system technology used since MY2007. 5 in the RAM pickup and will continue to use on the MY2010 RAM pickup. Manufacturers who choose to use the urea system will still have a particulate filter and will still be required to perform regeneration events.

 

[Steve St.Laurent]

From opjohnny 12-08-2009 01:25 PM



This is for Dodge and Cummins, Fess up, I want to know if you actually drive these trucks. I would like to hear about them if you do and how used. Dodge only question, I want to know what you have actually tried to change but was shot down by the bean counters.

 

[RamEngineers]

From RKohn 11-12-2009 09:46 AM



Hi Guys.



Thanks for all of the improvements that you’ve made to our trucks over the years. It’s great to see you seeking owner input, because now we're all going to be looking forward to many more great ideas. (Maybe if the bean counters would let you actually build them the way that you want to, we'd even see a truck that holds up as well as the engine. )



Why does Dodge continue to gear for these trucks for 55mph? Many of us spend the bulk of our time on the highway and 2100rpm @ 70mph…. just doesn't cut it, for either noise or MPG. We shouldn't have to spend thousands of extra dollars to put an aftermarket overdrive unit on a new truck when you could be offering an optional 3. 07 gear ratio to get it down around 1600rpm where it belongs (It's not like we won't have enough low end torque. ).



For all of the Go Green hype, why aren't you guys getting more behind biodiesel and working towards using higher percentages? I'd love to buy another new truck, but until you have solutions for some of the biodiesel issues that we've heard about, like oil dilution caused by the DPF regeneration... . I'm sticking with my 03.



Regards,



Rick

Hi Rick,

Thanks for the input. We are always struggling between performance, fuel economy and NVH. We'll take your point to heart on future axle discussions.

 

[doherty3153]

Why can aftermarket chip and module makers get greater fuel economy and we can't get it standard?

 

[CumminsEngineers]

From BDaugherty 11-13-2009 09:06 PM



I'm curious about Cummins' decision to use a DPF in the Dodge application instead of urea injection. I have read some of the pros and cons of each, but I would like to hear your comments.

It looks like you are mixing terminology a bit. Diesel particulate filters (DPF's) are used on all 2007 and newer on-highway diesels in the U. S. for particulate matter (soot) emissions reduction. Urea injection systems, however, are one of the technologies that can be used to reduce NOx emissions for 2010.



Cummins and Dodge do not need a urea system for NOx emissions reduction on the 6. 7-L Turbo Diesel for 2010 RAM Heavy Duty pickups. Rather, we use EGR along with an advanced NOx Adsorber Catalyst (NAC) to provide a package for the pickup market that does not require filling the DEF (urea) tank. Note that the NAC is the NOx-reducing aftertreatment component which allowed the Cummins 6. 7-L Turbo Diesel to meet 2010 emissions three years early back in 2007, and is not new for MY2010.



While urea (DEF) injection systems will be used commonly on other trucks, including the 2011 RAM Chassis Cab trucks, NOT having to refill the DEF system is an added convenience that only Dodge and CUmmins can offer to pickup truck buyers in MY2010.

 

[Steve St.Laurent]

From Matt400 12-05-2009 05:34 PM



Quote:

Originally Posted by nightowl (Post 2106502)

is the current 5500 chassis cab model suitable for class C manufacturers

Thats an interesting question. Wonder how big it could be? 4x4 might be nice for some folks.

 

[Steve St.Laurent]

From HBarlow 12-06-2009 02:28 PM



A similar question has already been asked regarding the new MOPAR 68RFE.



Does the Aisin six speed automatic used in cab and chassis trucks pump ATF in Park position? How about in neutral?



Reason for question is to learn how to cool ATF before shutting down after hard work such as backing trailer uphill.

 

[Steve St.Laurent]

From MLee 12-08-2009 09:38 AM



My question is, that on most heavy duty truck such as the 4500 and 5500 the power is de-rated why is this?

I would think that the extra power would be needed for the extra work required, not taken away.

Thank you.

 

[amsoilman]

If the UREA system is not being used on the 2500/3500 Diesel trucks, why is it being used on the 450/5500 trucks?



wayne

 

[RamEngineers]

From Super Briar 11-20-2009 09:04 AM



Could you give some info on just what is contained and or different with the Severe Duty Fuel Filtration Kit, for the 2010 6. 7L Dodge Trucks?



Does it have a fuel heater? If so does the heater have an on/off switch or is controlled by a thermostat?



Is this an option on the 2010 trucks or is it going to replace the standard fuel filter that was used on earlier 6. 7 trucks?



Can this kit be retrofitted to earlier 6. 7 trucks?



Thank you,

Wayne

The sever duty filtration is a Mopar accessory. The kit consist of new tank module with higher volume pump, 25 micron water stripping filter, additional WIF sensor, and the new F2 filter and filter. The heater is intragrated to the on engine filter housing.

 

[RamEngineers]

Ram engineer dudes, thanks for hanging with us tonight!



Would be great to see an air ride system from the factory. I have an aftermarket kit on my 2004 3500 and it improves the ride dramatically. Is the possibility good that we could see this?



Godspeed,

Trent

We currently do not have air ride, but we have made ride improvements for 2010MY thru mount tuning and the use of a hydromount for the cab to frame (better damping). All of the comments we have received so far has been very positive with respect to both 2500 and 3500 rides.

 

[RamEngineers]

Ram Engineers Is there any hope for the return of the 3. 07 gear ratio or something similar? Perhaps a double overdrive or 2-speed rear with a load sensor to kick out under hauling conditions?

Well, from a transmission standpoint, going to a 3. 07 (or similar) axle ratio is difficult due to durability concerns. Lowering the (numeric) axle ratio increases the vehicle's reflected inertia, which reduces trans durability since you have to input more torque from the engine in order to get the same vehicle performance. Or to look at it another way: If your engine produces, say, 650 ft-lbs of torque and you are making a WOT acceleration, even though the input torque to the trans is the same (650 ft-lbs), your acceleration will be slower (with the lower numerical axle ratio). Therefore, to get to the same speed, it will take more time, which means the transmission will see the same torque but for a longer time (hence, lower life overall, in terms of how many WOT accelerations you can sustain). Not only that, but there's a double whammy: Let's suppose (for example) that the 1-2 upshift occurs at 1000 output RPM. Suppose that equates to 10 mph with the current 3. 73 axle (I'm just guessing numbers here; they are not intended to be accurate). With a 3. 07 axle, that same 1000 output RPM will now be at a higher speed (say, 12 mph). So not only will you spend more time at high torque in 1st gear (because your acceleration is slower), you will ALSO spend even more time because you have to get to a higher speed to make the upshift.

I'm sure there are other concerns (from an axle standpoint) as well, but as you can see, changing to a lower numerical axle ratio is not a simple change and can have significant impact on other components. To maintain transmission durability, we would probably have to reduce the GVW and GCVW ratings when using a lower numerical axle ratio. Sorry for the long-winded answer here!!

 

[JShrum]

1) I have a 2007. 5 one ton flatbed getting 22. 9 mpg highway weighing 9000 lbs. , but it wasn't easy doing that. Why not make it like that from the factory? Using propane injection and a few other tricks. Is a 43% improvement from what you gave me from the factory. I am not a genius, but you engineers need to see one of these done up right. You might rethink how you do things. Am working on 26 mpg. and am almost there. Shrum Diesel. Do like the truck better than all others, though.

 

[CumminsEngineers]

I think the integrated turbo exhaust brake is a great feature of the Cummins Diesel. Would it work on Pre-MY07 engines?

The variable geometry turbocharger which provides braking functionality on MY2007 and later models can not be packaged with pre-MY07 engines. This particular turbo is performance matched and electronically integrated with the 6. 7L engine and not the 5. 9L product. Great to hear your feedback.

 

[Larry Willard]

With the cab and chassis trucks using Urea, will there still be an EGR in use and will the Urea reduce the amount of regeneration required, thereby allowing a longer life on the other parts of the exhaust system filter?