Pulling behind other trucks

[Texasdude74]

Most of the Paccars on the road are 455/1650 and that's just not enough. But 500/1850 will do most anything you need to do. There really aren't that many 2050 torque engines out there.

[Running rough]

aperently some guys have dyno tested with different boost levels, and on the dyno max torque was produced between 38 and 40 psi on the 2250, however with these cold frigid temps which can see below minus -30 Celsius up here in the great north strong and free, one has to moniter his boost because due to the nature of @m*m^2 tuning, cooler air will produce more boost, something to due with a certain vgt position at a certain rpm and trottle position vs mass flow calculation that stock Cals use, that's why some guys have to separate custom Cals with different turbo mapping, one for winter and one for summer, that's why a boost and pyro is so important when a guy does and tuning, my turbo is calabrated for warmer weather, so I keep boost in check with my right foot, however I would take rawzes advice and keep the boost lower to be on the safe side especially in cold weather, it is easy to get a viberation in cold weather when over boosting, (the cold air is so dense so it takes less boost to make the same torque) I believe the viberation is a symptom known as crank flex, defintlely not good for the engine as it can snap the crank, because it only is noticeable in cooler weather, I will say this, I have seen my Acert c15 do the same thing when it had a big boy tune with the variable valve timing disabled and making over 50 psi boost,

[Rawze]

(01-11-2017 )Running rough Wrote:  aperently some guys have dyno tested with different boost levels, and on the dyno max torque was produced between 38 and 40 psi on the 2250, however with these cold frigid temps which can see below minus -30 Celsius up here in the great north strong and free, one has to moniter his boost because due to the nature of @m*m^2 tuning, cooler air will produce more boost, something to due with a certain vgt position at a certain rpm and trottle position vs mass flow calculation that stock Cals use, that's why some guys have to separate custom Cals with different turbo mapping, one for winter and one for summer, that's why a boost and pyro is so important when a guy does and tuning, my turbo is calabrated for warmer weather, so I keep boost in check with my right foot, however I would take rawzes advice and keep the boost lower to be on the safe side especially in cold weather, it is easy to get a viberation in cold weather when over boosting, (the cold air is so dense so it takes less boost to make the same torque) I believe the viberation is a symptom known as crank flex, defintlely not good for the engine as it can snap the crank, because it only is noticeable in cooler weather, I will say this, I have seen my Acert c15 do the same thing when it had a big boy tune with the variable valve timing disabled and making over 50 psi boost,

You can't compare a cat to a cummins engine in regard to boost. They have much different designs, compression ratios, etc. both internally and externally. That is one common problem I see a lot of people do whenever I recommend a bit lower boost on the red engines.

YES, I always recommend to stay on the safe (lower) side of boost levels,.. and even you have pointed out just now in your dyno result that you are pushing it a bit far by comparing boost levels to torque output. For engine longevity, and reduction of liner issues, etc. you should always be slightly under where it peaks, not right at it, and certainly not above it. - This ensures the prevention of detonation, the reduction of piston/liner vibration, and ensures crank angles are not too low, resulting in crank flex like you have mentioned. -- Also, there are a lot of other factors that will alter where boost levels should peak vs torque, like timing, and about 10,000 other factors that determine final crank angle at high torque levels. -- Running higher than recommended levels of boost for more power is not the answer when considering longevity. Adjusting the entire engine with all its settings together is what is needed to do it safely.

For others reading this -- A lot of people do not consider that there is such thing as "too effecient", where that last bit of torque, or last bit of extra fuel mileage/efficiency, yes can be achieved, but at the cost of shortening the life of everything, and loosing the engine pre-maturely,. What good is another 0.4 mpg if you have to spend 28,000 inframing the motor prematurely to get it.

I am always the guy who fights tooth and nail against more power, or too much of a good thing, because most truck owners that I have met at the end of the day do NOT want to go anywhere near something that would cause them to have to pull their engine apart sooner rather than later. -- I see the trends of these newer engines leading up to show that the days of million mile engines are ending. It seems pretty clear to me, though the engine makers claim otherwise, that is the direction they are all taking. - Combine that with higher costs of parts these days, I would think that squeezing more longevity out of one would have the best long term profit over any power or other types of gains.

[fargonaz]

What could be some of the problems with de-tuning(i.e. lowering HP and torque) for longevity? For instance this truck that I have with the 369/922 tune.

[Rawze]

(01-11-2017 )fargonaz Wrote:  ...
369/922 tune.

eh?

What program is in it? -- That would be a CL????? number for a cm2250.

Factory HP and torque rating on the dataplate?

or what is the ESN (Engine serial number)?

=====

In any event, factory programming is rather conservative and is more geared around keeping Mr. Epa happy than it is saving you any fuel or doing anything else half decent.

Factory programming will pool the turbo up to ridiculous high positions at idle to dilute the exhaust so it will pass emissions, and to heat the engine up faster on cold start. That results in a factory constant internal 25-30hp internal engine load, sucking 40% more fuel at idle than is necessary all the time and creates more internal engine wear than necessary to boot. Factory programming also creates a lot of excess soot, then throwing the soot back into the intake via the EGR circuits,.. making the oil blacker than hell, creating carbon packing issues in the engine constantly, clogging and plugging up all the engine sensors, soot-packing overhead cam oil galleries and piston rings, and lowering fuel mileage purposefully to stay in compliance ranges.

There are really not any decent factory programs for them, they aren't allowed to make them and still be in compliance. Instead, programming from the factory is geared more towards shortening the engines life through excess wear due to soot in the oil all the time, unnecessary internal engine load due to over-spooling turbochargers, and starving the engine of proper oxygen levels, proper final crank angles, fual air ratios, etc. to purposefully lower fuel mileage so that you can't accidentally make too high of a fuel mileage so that the oil companies will not complain about it.

[Running rough]

the earlier isx engines Had a compression ratio of around 17.1, and as far as I know, did not have major premature liner block fretting issues, this became a commen problem with the first commen rail def engines the cm2250 which I am told had higher compression Pistons a smaller turbo and more back presure, there was a story going around that cummins wanted to meet the epa2010 emmisins with egr only the way navistar tryed but failed, and so without egr cummins bored the block of many isx blocks for 16 litre displacement with a thinner wall liner, however cummins had a change of heart when they seen the negitive effects of an egr only emmisins strategy, and decided that they would go with a mix of scr dpf and egr like most other engine manufacturers, however at this time they had already cast a number of overbore size blocks, (hence the different size liner outside bore diameter liner overhaul kits built in those years, I enemy think late model 871 engines had those bores and took those liners, however it proved it just was not these oversize bores that had liner fretting issues, my opinion is cummins simply shipped a lot of engines with not enough liner protrusion, and that the liner simply was not held tight enough and eventually got loose enough to fret and vibrate on the liner seat

[fargonaz]

79542557

[Rawze]

(01-12-2017 )fargonaz Wrote:  79542557

Yours should have the CL10136 program in it.

quickserv says...



CPL: 3719

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Insite/Incal says that program is for Linehaul (highway) applications and reaches 450HP when you get to 1800 RPM, and it falls off again to 369HP at 2100 RPM.

======

Looking in the program file itself reveals ...

345HP at 1100 RPM.
376HP as 1200 RPM.
439HP at 1400 RPM.
461HP at 1600 RPM.
450HP at 1800 RPM
368HP at 2100 RPM.

It actually peaks in HP 1650 or so rpm where it should.

Negatives ...
Like with many factory programs I have seen, the engine attempts to reach max torque by the time it gets to 1100 RPM, and this (opinion) is not good for an ignorant or abusive driver using the cruise all day and allowing it to lug. This tends to risk the liners long term, but is typical of red motor programming.

* Moderate fuel limiting is enforced, reducing the max fueling of the engine, even if it cannot achieve hp ratings to only about 70% of what the injectors can achieve. - This is also typical of fleet/highway programs, and (opinion) is a reason why a lot of cummins engines will only achieve about 70% of its HP rating on a dyno. The engine is quite often being starved of fuel on its upper end.

* (opinion) The fuel air ratio mappings (like most factory programs for the 2250/2350's, is set to over-fuel it at idle, and under-fuel it at max torque a bit. - Puffs of black smoke into that DPF can for those people who stomp the accelerator a lot, and burns a bit too lean, consuming extra SCR fluid usage at high torque. Typical of most factory red motor programs, nothing new.

====

Considering the build date of this enigne, I hope like hell someone has updated the fuel pump and plungers too by now.

[Rig Wrench]

(01-12-2017 )Running rough Wrote:  the earlier isx engines Had a compression ratio of around 17.1, and as far as I know, did not have major premature liner block fretting issues, this became a commen problem with the first commen rail def engines the cm2250 which I am told had higher compression Pistons a smaller turbo and more back presure, there was a story going around that cummins wanted to meet the epa2010 emmisins with egr only the way navistar tryed but failed, and so without egr cummins bored the block of many isx blocks for 16 litre displacement with a thinner wall liner, however cummins had a change of heart when they seen the negitive effects of an egr only emmisins strategy, and decided that they would go with a mix of scr dpf and egr like most other engine manufacturers, however at this time they had already cast a number of overbore size blocks, (hence the different size liner outside bore diameter liner overhaul kits built in those years, I enemy think late model 871 engines had those bores and took those liners, however it proved it just was not these oversize bores that had liner fretting issues, my opinion is cummi ns simply shipped a lot of engines with not enough liner protrusion, and that the liner simply was not held tight enough and eventually got loose enough to fret and vibrate on the liner seat

I'll add to this that earlier 570 and 870 blocks seem to be of much harder material. A 871 and 2250 will tend to cut pretty easy. The older blocks do a good job of eating cutter bits much faster