Revisiting DX3 power options....

[bclemens]

I think if you look at most people, most are fine with the power. Every now and then you get someone that isn't, but then 150 ft lbs of torque seem to make a difference, which makes me wonder how much could be placebo effect. not sure.

I would say 90% of the people I deal with have no issue with the power. If 40% complain, 30% of those is normally where the carpet is under the throttle pedal and has impeded the pedal from going to the floor, or the mode was set up reverse or they don't understand the "Mode" setting to begin with. Our default mode should be "performance". When you hit MODE it goes into Eco which starts in 2nd and changes the shift points. Sometimes I have seen that get reversed. So that leaves 10% that still might complain, but that is also why we offer the XL.

As for the extra 150 ft lbs tf torque...I think there is confusion because I am not sure you are getting what you are getting. For me to ORDER the chassis with 150 ft lbs of extra torque, it is over $2000 for that option. So if they are re-calibrating for under $200...then I wonder what they are actually doing.

If anyone here has had that done, shoot me your VIN and I can have our local Freightliner dealer look that up for the details.

[mookieblaylock]

My current trailer weighs just under 16,500lbs fully loaded out with two rigs, parts, spare tires, tools, etc. I've had mine recalibrated (FL VIN JM8449), and I've towed this load with both settings. I've detailed my thoughts on this before, but I'll try to summarize it again here:

1. Both calibrations will handle this load...no questions about it. @Aztec1382 - the DX3 has zero problems towing 10k lbs. The 20k towing capacity is what landed me here as well, and I have no regrets.

2. Regardless of the mode setting, the Allison shifting algorithm seems to be based on two related priorities - get to 6th gear as quickly as possible and stay there as long as possible. I've read on here where others say that they basically floor it until they are up to speed. My experience is that with the 350/1000 calibration, you pretty much have to do this to keep it from falling on it's face once it shifts to 6th gear (5th even depending on the situation).

3. The published data on the two calibrations shows peak HP and peak torque measured at the same exact RPM's - 2000 RPM for peak HP and 1400 RPM for peak torque. If you do the math, what these numbers boil down to is a 40HP gain at 1400 RPM (306HP vs. 266HP). If you can visualize the HP/RPM graphs, the 350/1000 graph would be a relatively straight diagonal line (going up from left to right) peaking at 350 at 2000 RPM. The 350/1150 graph would have a much steeper diagonal line between 0 and 1400 RPM, and a much flatter (almost horizontal line) between 1400 and 2000 RPM.

4. At the end of the day, 350 peak HP is 350 peak HP. The only difference is over what RPM range that HP is available. Most here will agree that you need to manually shift the Allison in the hills...especially when pulling a load. To me, what they're saying is that you have to keep the engine speed up near 2000 RPM in order to stay in the power band. That power band is much wider with the 350/1150 calibration. The coach still loses speed when pulling grades, but it does so at a much slower pace. I can still manually downshift if I want/need to, but I find that I rarely have to anymore. I also never have to floor it from a dead stop anymore. When the Allison shifts into 6th gear at 45MPH and the engine speed drops way down, I'm still in the power band.

So, to me, it's really like the Allison was programmed specifically for the 350/1150 calibration. I'm sure for the linehaul application, where the rig runs several thousand miles a week over the same flat interstate, it's probably more fuel efficient, but, other than that, I honestly don't know why they even offer the 350/1000 option.

Where's that 'man beating a dead horse' emoji?

[FOURWHL]

[mookieblaylock]

HA...there it is!!!

[wfo9]

Originally Posted by bclemens

As for the extra 150 ft lbs tf torque...I think there is confusion because I am not sure you are getting what you are getting. For me to ORDER the chassis with 150 ft lbs of extra torque, it is over $2000 for that option. So if they are re-calibrating for under $200...then I wonder what they are actually doing.

If anyone here has had that done, shoot me your VIN and I can have our local Freightliner dealer look that up for the details.

Bingo and exactly what I was trying to explain. CONFUSION When I talked to the rep he said it had to be ordered with it. I was not sure if that was just a mkt thing and a way to make more money or some truth to it. There was a claim about the drive line setup needing to be different for the 1150 to be valid on the chassis. I have no idea if this is really accurate.

Now it seems some here have gotten it re-calibrated (which is an uprate in TQ) from the 1000 to the 1150, but it's sure is questionable all around about where the disconnect is. As many have tried and been turned away after many attempts and calls to cummins and FL.


And I agree, there is a very noticeable difference. I drove two similar, one with the additional 150... and it was not night and day..., but very noticeable to me. But then again, there can always be placebo and these motors clearly run at different modes all the time deepening on conditions and the regen state. Mine sometimes feels very strong and other times drops off a bit. But I feel no need to manually shift most of the time.

So I guess the real question is what does FL do for the additional TQ if anything. If they could explain what you get for the 2k... besides just a different calibration that would help clear things up.

[wfo9]

I know this is a bit of a dead horse to some, but I know several folks (not here) who have been trying to find a way to get the cal upated and keep hitting a brick wall. The actual cal info posted earlier was very useful.. but some service centers still apparently refuse.

[bclemens]

I wonder if they are just using a different transmission programming. I have tasked my FL rep with getting more info.

[mookieblaylock]

I had mine done at a Cummins service center, and the ticket shows the actual Insite (their diagnostics/programming tool) software names/versions. I'm certain they didn't/wouldn't touch the Allison. Additionally, I can't tell any difference in when/how it shifts...it just has more power now when it upshifts and the engine speed drops.

[The Renegade]

Somebody correct me if I’m wrong and I know this is not a tuner, but does tuners not over the ability to change shift points?

Also since it’s a recalibration, would the shift points not change also? I wish the tranny would hold each gear a few more RPM’s because when it gets to 6th so quick it kinda just pukes.

[DR Quest]

You would have to recalibrate the TCM. I would think they have a fuel milage calibration in it now, they can reset it for higher shift points would feel like more power.

[wfo9]

Yea, the ECU and TCM are pretty isolated in these big rigs (cummins/Allison). The TCM still needs input from the data bus, but it is pretty basic stuff (RPM, Load, Throttle position, Speed)

The Allison does have the mode button for economy, but even in "performance" mode it seems to shift very quickly through the gears trying to get to 5th and 6th.

For instance, there is steep hill I climb coming out of my neighborhood after a stop sign. Even if I Floor it, it will make its way up to 5th or 6th very quickly, but then it will eventually downshift to gain some speed and pull the hill which is probably a 10% grade. Never had a transmission in anything that would do that with foot on the floor. It would typically hold the lower gear until it got all the possible speed out of it. It seems to do that in first and second gear, but then 3rd and fourth it seems to shift well before redline.

Now I could probably use the buttons to set the max gear to 3rd or 4th and it would pull it much better, but I should not have to do that.

[RV Randy]

I think Mookies detailed explanation explains it clearly, and I do not believe it is placebo effect.

As everyone seems to agree, the Allison rapidly up-shifts without letting the RPM build into the best power band with the standard calibration.

The re-calibration simply moves the power band down into the lower RPM range where it can be used most effectively before the Allison up-shifts.

I suspect if you put 2 identical units side by side, one setup standard and one with the revised calibration you would see the following results:

Put both units in D, punch both WOT and do not manually control the up-shifts, the recalibrated units pulls ahead because it is in its best power band earlier at the lower RPM, until you reach a certain speed (45 mph?) and then both units continue accelerating at the same rate. Possible that the standard unit may pull better at the higher speed and catch up because it will have the advantage of being in its max power band once the RPMs build as it gains speed.

Repeat the same exact test except keep the re-calibrated unit in D and do not manually upshift, manually upshift the standard unit once it reaches the 2000 RPM point and both units probably accelerate at the same rate.

For most folks that dont tow heavy regularly, the standard set up may even be prefferable because they probably prefer having more power available on the top end for quicker passing response or maintaining speed on uphill stretches of highway.

There may even be a downside to the recal i.e. pulls much better at the low end may may not be quite as strong on the top end. We'll have to see.

As far as the $2000 cost when new or $250 or so done in the field, thats probably basic marketing. Maybe the official guidance is dont do it in the field for $250 so it forces folks to get the same thing new for $2000 grand. But the techs have to have the ability to legitimately reprogram ECM units in the field in case a new ECM has to be installed, so they have to be able to program your factory parameters into the new ECM whether you have the 1000 or 1150 program from the factory. The smarter shop managers have discovered a chance to generate more revenue for their shop by doing this. If FL figures out they are losing too much because of this, they will hard code the ECM's so if you have to have one replaced you will have to order the 1150 version and pay the $2000 unless your VIN shows it came from the factory with the 1150.

[wfo9]

Originally Posted by RV Randy

I think Mookies detailed explanation explains it clearly, and I do not believe it is placebo effect.

As everyone seems to agree, the Allison rapidly up-shifts without letting the RPM build into the best power band with the standard calibration.

The re-calibration simply moves the power band down into the lower RPM range where it can be used most effectively before the Allison up-shifts.

I suspect if you put 2 identical units side by side, one setup standard and one with the revised calibration you would see the following results:

Put both units in D, punch both WOT and do not manually control the up-shifts, the recalibrated units pulls ahead because it is in its best power band earlier at the lower RPM, until you reach a certain speed (45 mph?) and then both units continue accelerating at the same rate. Possible that the standard unit may pull better at the higher speed and catch up because it will have the advantage of being in its max power band once the RPMs build as it gains speed.

Repeat the same exact test except keep the re-calibrated unit in D and do not manually upshift, manually upshift the standard unit once it reaches the 2000 RPM point and both units probably accelerate at the same rate.

For most folks that dont tow heavy regularly, the standard set up may even be prefferable because they probably prefer having more power available on the top end for quicker passing response or maintaining speed on uphill stretches of highway.

There may even be a downside to the recal i.e. pulls much better at the low end may may not be quite as strong on the top end. We'll have to see.

As far as the $2000 cost when new or $250 or so done in the field, thats probably basic marketing. Maybe the official guidance is dont do it in the field for $250 so it forces folks to get the same thing new for $2000 grand. But the techs have to have the ability to legitimately reprogram ECM units in the field in case a new ECM has to be installed, so they have to be able to program your factory parameters into the new ECM whether you have the 1000 or 1150 program from the factory. The smarter shop managers have discovered a chance to generate more revenue for their shop by doing this. If FL figures out they are losing too much because of this, they will hard code the ECM's so if you have to have one replaced you will have to order the 1150 version and pay the $2000 unless your VIN shows it came from the factory with the 1150.

I still don't exactly follow your understanding at all. 15% more peak torque does not mean less torque/power will be produced at higher RPMs. They both make the max torque at the same RPM 1400. They both fall off to the same torque at max HP RPM 2000 which is 920 ft/lbs. The in-between is a bit unknown, but from tuning engines and racing for 20+ years, any reasonable person would assume it simply decays to the same target resulting in more power at all RPMs besides Max where they will be equal.. Most of these diesels are very flat until they start to fall off just before redline. The calibration is much more in controls since the RPMs are so low and the VE does not change much at all.



They most likely provide the 350/1000k for longevity and MPG purposes. The torque multiplication down in the lower gears can be quite a load on components ...150 additional ft/lbs at the crank multiplies out to significant increase in the drive-line in the lower gears (especially on a big rig where traction is not really limited).

Similar to the next step up in calibration, you might need additional capacity in the weak links to be confident in it. I have no idea what the weak points are but FL should. Not having it does not mean problems either, but they may want a bit more from a warranty perspective.


Here is the only chart I could find from cummins. It is for the 1250/450 cal L9, but I would assume the others would be similar just down 100 on both HP and tq. In fact the 1150/350 would probably be an exact curve match, just shifted down 100. The 1000/350 would be similar just start lower and decay slower and be a bit flatter on the TQ side with the same peak HP.

[Orangecrush]

While this may be a dead horse to some, at the end of the day when I am crawling up a hill at 35mph, pulling less than 10K, it won't be a placebo effect if I can drive up that hill at 45-50. I've got just shy of 10K miles on my RV and 95% of that is pulling the same trailer.

I have tried taking runs up the hill, changing gears, shifting manually all with the same result... me creeping up a hill at 35mph. Granted, these are long steep hills (3-5 miles at 7% grade) but surely I can go faster than I am. My buddy has a Newmar with 50 more HP and 150 ft lbs of torque and out runs me every time going up a hill. Ridiculous.

(and no, it's not who's faster going up the hill between him and I)


Mark

[wfo9]

If you can get the 1150 calibration it should help a noticeable amount, but you still won't be tearing it up by any means.... Avg increase is probably 10%... But only like 5% in the areas you probably cruise the most. The surge at 1400 to help get you going is what mostly helps. I found some data on the two calibrations (or at least some that appears to be very close) here is what the curves look like to help people understand it. It's more power everywhere except the same at one specific RPM.

I got the data from the international truck website.. Funny thing is they list the 1150 cal as 345hp, but when I overlaid the charts it appeared to be a hair above the 350 cal even at peak hp RPM. My guess is they just labeled them differently to avoid mistakes in ordering.

If you can really get it with no warranty issues... Do it. It would even be worth traveling to find someone that would as it sounds like other have found some shops that will.

The blue line is the 1150 cal, red is the 1000 cal. I can't guarantee the accuracy of these numbers as I pulled it from a fuzzy image, but I'm pretty confident it is within a 5% margin of error. There is also some smoothing applied the lines.

[17 Oaks]

Originally Posted by Orangecrush

I made a post quite a few months ago about power or tuning enhancements for the DX3.

One of our members got a OEM upgraded tune that added 150'ish ft lbs of torque. Unfortunately when i called the dealer, they said that the 2018 LB9 engines were already maxed out torque wise.

That said, there were some companies coming out with tuners (which I don't understand why if it's "maxed out")

After coming back from KY with my rzr in an enclosed trailer, I simply need more power. I'm tired of starting off at the bottom of a hill running almost 80 (limiter maxed out) and running 35 when I hit the top of the hill.

The DX3 does great not pulling anything but clearly it's not enough. I have no idea how Dynamax can advertise that the DX3 has a 20K lb towing capacity. While the frame may be able to tow that much, the engine power would drive you crazy.

Has anyone found anything yet? Last time I checked, there were 3-4 companies that were just about to release their tunes but hadn't yet.

Anything?

Thanks,

Mark

Orange, the world of HP/Torque is a complex one at best. FREQUENTLY you do not get extras torque, instead what you get is torque taken form somewhere on the performance band and moved to another location. You can do it thru tuning and or thru mechanical, generally thru the use of different cam profiles or thru gearing.

Bear in mind that often gaining on the top end you give up on the bottom end and vice versa.

The question you must answer is where do you want your power? Spend all you time driving up mountains, driving across flats and pushing the speed limit? Or drive the back roads rarely hitting over 55 mph. ID you're driving style and have your engine performance to match. One of the posters suggested going to your engine dealer and have them do it, good idea!

[mookieblaylock]

The data you found is for the ISL9 vs. the L9. The comparable calibration on that engine was 345/1150. Below are the actual HP and torque graphs from Cummins for all the available calibrations of the ISL9. The graphs we're comparing are the brown (350/1000) and purple (345/1150) lines. I don't have the same for the L9, but I think it's safe to assume the data is very similar.

With regards to whether there are any trade-offs...if you're robbing Peter (at high RPM's) to pay Paul (at lower RPM's), I think these graphs clearly show that is not the case. The difference is not simply moving the power band, rather, it's widening it.

@Orangecrush, my 'beating a dead horse' comment was not directed at your search for more power. I sympathize with you and can relate to the issues you're trying to solve. I just don't understand why most folks tend to believe this cannot be done, or that the recalibration, if it can be done, is placebo, at best. My local FL and Cummins service centers wouldn't even talk to me about this...every time I brought it up, I got the same canned response - it's an RV; all RV's come maxed out from the manufacturer; there's nothing we can do. They didn't even look into it. I had to drive a couple hundred miles to a Cummins service center that actually took the time to research the options and was willing to perform the work. If we were close enough, I'd gladly give you my rig and let you test it out with your trailer and decide for yourself...as long as you didn't take it down a 20 mile dead end gravel road or try to cross an 8' wide bridge.

[wfo9]

Originally Posted by mookieblaylock

The data you found is for the ISL9 vs. the L9. The comparable calibration on that engine was 345/1150. Below are the actual HP and torque graphs from Cummins for all the available calibrations of the ISL9. The graphs we're comparing are the brown (350/1000) and purple (345/1150) lines. I don't have the same for the L9, but I think it's safe to assume the data is very similar.

With regards to whether there are any trade-offs...if you're robbing Peter (at high RPM's) to pay Paul (at lower RPM's), I think these graphs clearly show that is not the case. The difference is not simply moving the power band, rather, it's widening it.

@Orangecrush, my 'beating a dead horse' comment was not directed at your search for more power. I sympathize with you and can relate to the issues you're trying to solve. I just don't understand why most folks tend to believe this cannot be done, or that the recalibration, if it can be done, is placebo, at best. My local FL and Cummins service centers wouldn't even talk to me about this...every time I brought it up, I got the same canned response - it's an RV; all RV's come maxed out from the manufacturer; there's nothing we can do. They didn't even look into it. I had to drive a couple hundred miles to a Cummins service center that actually took the time to research the options and was willing to perform the work. If we were close enough, I'd gladly give you my rig and let you test it out with your trailer and decide for yourself...as long as you didn't take it down a 20 mile dead end gravel road or try to cross an 8' wide bridge.

Makes sense they were using the ISL9 names.. but it did say L9, and when I aligned their charts the 1150 cal was actually a tad more tq at all rpms. So I assumed it was possibly the correct data, just with the old label.

Bottom line either way.. more power at all RPMS. Interesting that the cummins chart shows the ISL 345 as flat HP curve from 1600-1900 where all the hwy driving takes place.

It would be nice to know what RPMs are ideal for climbs. I seem to remember 1750 being about the best place to be to maintain a steady speed on a grade.

[bclemens]

My understanding is the ISL9 and L9 is the same. It's just how they market it (L9 being the "newer" choice in terminology) for their 8.9 engine....which is rounded up in the first place.

[mookieblaylock]

According to briefing announcing the 2017 version (the L9 vs. the 2013 based ISL9), there were only a couple of changes - namely a change in the stage 1 fuel filter design, and the consolidation of the aftertreatment components into a single module. For the L9, this is what Cummins recommends with regards to RPM and performance/economy: