do I need the ho cummins

[TFucili]

Lots of idiosyncrasies on the RAM build site.....some that take quite a while to ever get corrected.

The short story is.......RAM does not build an SO Cummins with the AS69RC in the 3500 pickup series.

Ram's "Build Your Own" function is powered by a 6.0...

 

[AH64ID]

Just tried to build a 3500. When you select the Std Cummins, you get a popup that tells you there was a change, which is the 68RFE. Then, if you select the Aisin you get another popup saying the engine has changed.

Then, started over, and went right from the base 6.4/ZF to selecting the Aisin, and it forces the HO.

Same, no way to get a Aisin with the SO.

 

[Andy Morrison]

My new 2019 3500 drw has the HO . Get it or regret it.

 

[Wiredawg]

Skorski,

After all this VALUABLE info, please let us know what you decide with all the details. Good luck figuring it out.

Cheers, Ron

 

[skorski]

I had the same problem on the build sight withho and aisin I think building at the dealer may have a direct line to the build sight will try it when they start building again

 

[skorski]

I had the same problem with the build sight with the ho and aisin I think the dealers web sight might be deferent as they mat have a direct line to the build plant I will try at the dealer when they start building to order the aiain with the standard cummins

 

[AH64ID]

I had the same problem with the build sight with the ho and aisin I think the dealers web sight might be deferent as they mat have a direct line to the build plant I will try at the dealer when they start building to order the aiain with the standard cummins

You won’t be able to order a SO Aisin, it’s not an option nor has it been since the Aisin was put into the pickup in 13. The Aisin is always the HO motor, now there just happens to be mechanical differences between the SO and HO. Just look at the brochure and specs.

So if you want a Aisin you’re getting an HO.


Good news is the SO for ‘20 has the same torque as your ‘14 H.O. and only 15 fewer hp so you likely won’t tell a difference power wise, but the 68RFE does drive different.

 

[Cummins12V98]

I test drove a 19 at May Madness with the AISIN, it felt no different than my measly 15 AISIN. Would be interesting to take one and tow my 35k combined for comparison

 

[Newsa]

there just happens to be mechanical differences between the SO and HO. Just look at the brochure and specs.

There are programming differences. Can you elaborate on any physical/mechanical differences in the engine?

 

[AH64ID]

There are programming differences. Can you elaborate on any physical/mechanical differences in the engine?

The 19+ SO and HO motors have different pistons, but I am not sure what else is different.

 

[Newsa]

The 19+ SO and HO motors have different pistons, but I am not sure what else is different.

Yes, they report that the HO has lower compression than the SO. Whether this is accomplished by reducing the stroke, piston shape or head shape.... it seems they reduced the 19.2 to 1 compression ratio to somewhere between 16:1 and 17:1 to accommodate the higher boost. This could also improve the longevity. Because squeezing more torque out of the old high compression ratio could stress parts enough to shorten it's life.

Is there still EGR recirculation?

 

[AH64ID]

Yes, they report that the HO has lower compression than the SO. Whether this is accomplished by reducing the stroke, piston shape or head shape.... it seems they reduced the 19.2 to 1 compression ratio to somewhere between 16:1 and 17:1 to accommodate the higher boost. This could also improve the longevity. Because squeezing more torque out of the old high compression ratio could stress parts enough to shorten it's life.

Is there still EGR recirculation?

It's reduced with the pistons. SO is 19:1 and HO is 16.2:1. The higher boost is a big part of why they reduced the compression. 19:1 is pretty high compression, the highest of any Cummins in a Dodge/Ram, and could be part of why the newer trucks drink more DEF. It's likely higher to help with fuel economy, but it has to be pushing some decent cylinder pressure at WOT. I wonder if they 19+ SO's will be harder on HG's when tuned than other 6.7'.

Yes they both run EGR.

 

[Jim W]

It's reduced with the pistons. SO is 19:1 and HO is 16.2:1. The higher boost is a big part of why they reduced the compression. 19:1 is pretty high compression, the highest of any Cummins in a Dodge/Ram, and could be part of why the newer trucks drink more DEF. It's likely higher to help with fuel economy, but it has to be pushing some decent cylinder pressure at WOT. I wonder if they 19+ SO's will be harder on HG's when tuned than other 6.7'.

Yes they both run EGR.

Why would you want to tune one of the newer Cummins with the HP/TQ ratings that they have now?

I know why I tuned my 2008, truck but it was not for an increase of HP/TQ, although I am using a little more than stock now!

 

[AH64ID]

Why would you want to tune one of the newer Cummins with the HP/TQ ratings that they have now?

People will always want to tune them, regardless of how much power they have stock.

I have no intentions of adding any power to mine, but it will likely get a small emissions "friendly" tune when the warranty is gone.

My statement was purely based on the 6.7's ability to have HG issues at added power and the new higher compression ratio.

 

[Wiredawg]

I know I've posted previously, but comments made since then have spurred more thought about the OP question. From my 2nd Gen, two 3rd Gens, one 5.9 and one 6.7, and my current 4th Gen, I've always found for my purposes, close to 400HP and 800Lb ft of TQ provide the towing grunt and daily drivability. There are way more SO Cummins/68RFEs being built than HO/Aisin trucks. It's made my head hurt trying to compare drivability and reliability without any real trend either way.

It might just boil down to butt in the seat feel and comparing costs. I'm a techy sort of guy, so I recommend writing down all of the quantitative and qualitative elements you can think of. 1st to 2nd, 2nd to 1st shifting, smoothness of shifting, EB on/off, TH on/off and combo. Accelaration from a stop and getting on expressway. EVIC set to show system temps and compare. Assign a weighted score for each element, but total cant exceed 100.

I know I could look back when your truck was wreckedto see what transmission you had, but if it was a 68RFE, you may have a leg up on the horse comparing. I dont recall anyone mentioning advancements or version improvements in the 68RFE, but I do know there were substantial improvements from the AS68RC and the AS69RC programming and mechanicals.

So, not sure even I can throw any more spaghetti on the wall for this subject.

Gonna be REAL curious what you end up getting

Nothing like the joy and fun of getting a new truck.

Cheers, Ron

 

[NonFord]

The 19+ SO and HO motors have different pistons, but I am not sure what else is different.

I also wonder with the different pistons, are the head studs also different?

 

[NonFord]

Why would you want to tune one of the newer Cummins with the HP/TQ ratings that they have now?

I know why I tuned my 2008, truck but it was not for an increase of HP/TQ, although I am using a little more than stock now!

Because it runs soooooooo much better!!!!!

 

[AH64ID]

I also wonder with the different pistons, are the head studs also different?

I’d need an ESN from each to find out, but likely not. Cummins will make more money with fewer part numbers, but then again they have 2 different motors for FCA... I’m still surprised at that.

 

[skorski]

right now I am leaning to the 68 rfe thanks to this post looks like a little over kill with the aiain I pulled my 35 ft 15k from missippissi with a 2019 with13k very nice smooth shifting for 15k miles cant see spending an extra 3K for something I do not need

 

[Jim W]

No I don't think it will! I talking about a 2019/2020 truck, not the earlier models. Between myself and my two boys we have 4 Ram Cummins trucks. So, I do have a little experience with them and what it takes to modify them. My older son has two of them a 1996 and a built 2006 truck with 800+ HP. My younger son has a 4th gen truck that has seen some work done on it, the truck is a 2013.5 model. With mine being a 2008 truck with 60HP/120lb-ft TQ overstock.

There comes a time in every day drivability with excessive HP and TQ do not help, but causes issue. I seen it many a time in the 60's with gas engine vehicle.