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tuning question - ptlogan77 - 05-14-2022

I am new to the forum, so please excuse my ignorance if this subject has been covered.
I have been a lifelong yellow motor guy, but last year I purchased my first Cummins since I had an NH220 42 years ago.
These red motors are quite different than a cat, and I'm trying to learn as I go.
The Truck is a 2018 Peterbilt 389 with a CM2350 X15 CPL4343 that has the EGR, DPF, SCR, and DEF system removed. I have kept the VGT turbo, and have no complaints with it.
The proper Cummins coolant bypass pipe has been installed in place of the EGR cooler, and the ECM has been tuned by a tuner that was recommended to me locally here in Washington, and is supposedly set at 565/2050.
The engine has 20,000 miles on an in frame (liners, pistons, rods, mains, oil pump, new head with Inconel valves)
The specs on the truck are: 280 wheelbase, Flat top sleeper, RTLO18918B transmission, 3.25 rears, LP24.5 tires, rolls down the road at 60mph in direct gear at 1600 rpm. I pull a van and a reefer.
I know with the long wheelbase and flat top sleeper I'm giving away some fuel, but I'm struggling to get 5.1 mpg and on my most recent trip to Boise and back (1200 miles) I averaged 5.2 running half the trip empty!
The current tune keeps my EGT's below 800 when running below 1500, with plenty of torque to run it down there, but above that on a long pull I get over 900, and I'm aware that the VGT turbo is not a fan of high temps.
In my feeble brain, it seems that the ECM must be getting more fuel at higher rpm, causing the extra exhaust temp, which seems counter-productive for my goal of better mileage and not having to lug the engine.
I'm looking for help with a better tune for my application.
I'm not looking for a generic "Hot rod tune", and am wanting to learn as I go. Any help or direction would be appreciated.


RE: tuning question - windowrattler - 05-14-2022

First thing to do is to pull a copy of the tune and send it over to Rawze to take a look at it. Speaking from personal experience you can have a tune that seems to run ok but is stuck in a warmup mode and sucks the fuel as an example. After a review and a complete retune went from 4.5-5.3 mpgs to 6+.


RE: tuning question - ptlogan77 - 05-14-2022

(05-14-2022 )windowrattler Wrote:  First thing to do is to pull a copy of the tune and send it over to Rawze to take a look at it. Speaking from personal experience you can have a tune that seems to run ok but is stuck in a warmup mode and sucks the fuel as an example. After a review and a complete retune went from 4.5-5.3 mpgs to 6+.

Ill get a datalink adapter as my Grandview USB Adapter doesn't want to play well.
Any suggestions on which adapter to get? Which programs do I need?
I have a subscription to TeamViewer, so as soon as I get an adapter I'll be ready to go.


RE: tuning question - Rawze - 05-14-2022

(05-14-2022 )ptlogan77 Wrote:  
(05-14-2022 )windowrattler Wrote:  First thing to do is to pull a copy of the tune and send it over to Rawze to take a look at it. Speaking from personal experience you can have a tune that seems to run ok but is stuck in a warmup mode and sucks the fuel as an example. After a review and a complete retune went from 4.5-5.3 mpgs to 6+.

Ill get a datalink adapter as my Grandview USB Adapter doesn't want to play well.
Any suggestions on which adapter to get? Which programs do I need?
I have a subscription to TeamViewer, so as soon as I get an adapter I'll be ready to go.

just get an iline-6 adapter off of flea-bay or from obd2-com. A china knock-off works just fine for about $300 bucks or so. The software needed to pull the file out of it, etc. is easy enough to get a hold of after that.. it is on the inter-webs for free in a few places.

assume the program is bad.. more than 90%+ or all the hundreds of programs that I review each year are.. because there is mostly nothing but clowns out there doing that stuffs who have no absolute clue how these engines work.. but can only manage to barely jail-break it from showing some faults in the dash ... maybe hack some more power into to it all half-arssed like .. and nothing more... resulting in a severely shortened engine life in exchange for some DPF faults going away.


... and The power is not the issue so much to about 600 HP or so .. but that ISX engine HATES lower RPM and higher torque!... so I would suggest you get rid of that 2050 torque, unless you only want the engine to last half as long... and learn to drive it above 1500rpm and a gear or 2 down, whenever loaded heavy and/or climbing those hills.

The 3.27 rears don't help much in the way of it climbing those mountains out west too. That is not a very good setup for engine longevity at all and would make it work harder than it should all the time. ... and what model tranny exactly do you have that your claiming is a direct?.. maybe look on the side of it at the sticker... post the pic of it here.

===========

and you are absolutely right.. THAT RED ENGINE IS NOTING WHATSOEVER LIKE ANYTHING OF YESTER-YEAR.. AND ABSOLUTELY A DIFFERENT ANIMAL THAN ANY YELLOW MOTOR!... DO NOT EVEN TRY TO MAKE COMPARISONS.. NOTHING ABOUT IT IS THE SAME AT ALL!> .. not how much boost, or fuel or rpm ranges, or ANYTHING is the same about it whatsoever.

In the mean time, how much boost will it make/ get up to in a hard pull if you give it everything you got while loaded heavy?

And how fast are you driving that flying brick that belongs in a museum... because it is Absolutely a fuel-pig of a truck.. and how much you can manage to SLOW THE HE#LL DOWN BELOW 63 MPH will make more difference than all the magical programming in the world combined.

Get an inline adapter.. copy the program out of it and e-mail it to me for a proper review.. and then you can go from there towards making proper decisions about it.

==========

Last but not least.. THE OEM HEAD IS GOOD FOR MORE THAN a MILLION+ MILES unless the engine is abused in some significant way!!!>>> and ALL I SEE AROUND HERE, with those aftermarket/reworked heads that you mentioned is nothing but absolute garbage.. you should have put on a BRAND NEW OEM-ONLY HEAD.. and not wasted your time and money on the trash that someone did to it. You need to save your moneys up like mad.. because I guarantee that thing is not going to last but a few years at most before it needs another inframe because of that garbage head that was put on it + whatever other half-arssed things that were done. Was the overhaul kit itself OEM?,, or was it more after-garbage parts too?... and what was the liner height that it was machined to?.. that is just as important... because so far, your descriptions point directly towards a lot of half-arssed, ignorant things done and a bunch of trash.


RE: tuning question - ptlogan77 - 05-14-2022

As I stated, the truck runs at 1600 in direct.
RTLO18918B transmission.
16th gear is direct gear. the top two gears are both overdrive and are hard on the countershafts since the RTLO18918 only has journal bearings on the countershafts instead of roller bearings like the RTLO20918 has.

Direct is by far the best highway gear for transmission life because of the amount of torque required with the 3.25 rears which I agree is not the most efficient rears for the west coast.

My bread-and-butter run is 1000 miles north in BC on mostly flat roads empty one direction, so the rear gearing and running in direct works out well.

I agree that above 1500 is the best place to be, and 63 is about the max I run in Washington as the speed limit is 60.

I'm sure that the tune is less than perfect, because the higher the RPM when pulling a pass, the higher the EGT's.

The max boost is about 36-37 lbs, and since I still have the VGT turbo I have great engine braking with boost up to 38lbs on stage 3.

I'm not looking to get 7.0 mpg, as would be impossible with my "flying brick" but would like to be able to run at a higher rpm and not feel that I'm over-fueling and under-boosting, causing higher EGT's as the rpm's rise.

I will get the Inline 6 adapter and then have you walk me through copying the ECU program.

I have no issues with the head, I went through it before installation including removing the valves, checking all parts, and checking the lap with Prussian blue. I lapped all the valve seats and had the deck surfaced to ensure a perfectly flat surface.

I must say that the water temp stays down below 210 even on a hard pull, so overheating doesn't seem to be an issue.


RE: tuning question - Rawze - 05-14-2022

(05-14-2022 )ptlogan77 Wrote:  ...
The max boost is about 36-37 lbs, and since I still have the VGT turbo I have great engine braking with boost up to 38lbs on stage 3.

...

THAT IS ABSOLUTE ENGINE TORTURE!!!..... It is over-boosting.. and the engine brake .. if it is able to get to 38 psi... has been most likely jacked up too and is eventually going to destroy that engine. I.E.> crack the head, maybe bend a vale, or send a piston thru the block with absolutely zero warning.

(with no more egr gas going into the intake) The x15 only needs about 30-31 psi or so to make 600+ HP 32 being the upper limit before causing harm ... and engine brake set to more than about 28~ish lbs of boost or so is going to eventually cause it to drop a valve. - those numbers that you describe so far point directly towards a possible bad delete where someone jacked with the engine brake settings and did not have a clue how to correctly re-program the turbo to make a proper fuel-air-mix. - You should be worried.. REALLY worried!.

also, it seems like most of what you are saying makes little to no sense. You have been led down some kind of rabbit hole by a bunch of engine and truck abusing collection of morons at some point.

That is not a direct-drive tranny at all... it is a 0.73 over tranny.

YOUR TRUCK IS GEARED TOO TALL FOR THAT TRANNY!

here is the reality of how that truck is spec'd...
http://rawze.com/forums/showthread.php?tid=7223&pid=71474#pid71474

How about you go rent a truck with the same make/model, engine, tranny, and everything with a proper set of 4:36's in it and see how much better it drives and gets out of its own way IN EVERY SINGLE GEAR YOU PUT IT IN. See how much easier that truck gets up and going with heavy freight behind it, etc... - and when driven right ... how much better fuel mileage it can make with exactly the same loads simply because it is not geared too tall for the application.

As someone who knows how to drive a truck properly.. and has test driven hundreds and hundreds of trucks with every kind of gear ratios out there .. it becomes obvious real fast.

Your only fooling yourself at this point by continuing to disagree, because your not going to fool me. I have been there and done that over and over with too many people and trucks to know better.

Also, even when simply test driving a truck.. immediately, when the truck has a decent set of rears in it,.. you can simply feel it.. it accelerates like it was designed to pull that 80,000 lbs.. and every single time I get into a truck with those tall arsse rears that are not fit for a pick-up truck... the damn thing always feels sluggish because EVEN THE LOWEST GEARS IN THE TYRANNY ARE TOO TALL FOR THOSE TALL REAR ENDS) .. the person driving it is always pushing the pedal a lot harder because IT just does not want to get out of its own way compared to something that was geared right, once the truck is loaded heavy. - It is terrible, and the engine has to work a whole lot harder just to sling it around.. in every single gear range.. you can just tell something is wrong with it compared to something that was actually geared for its intended application.

so if I were given that truck, I would be saving up for a decent set of rear ends to put in it and get rid of those tall garbage engine killing rear ends, unless all it was going to do was haul around a bunch of flowers that don't weigh anything.

=========

last but not least... higher RPM in the ISX does not mean less fuel mileage once the engine is loaded down. There are days where we don't even use 10'th gear (we have a 10 speed)..and the engine is always up at 1500-1900+ all day long .. and we still break 9+ mpg with it grossing 80,000lbs with water totes, big paper rolls, coils of wire, wood pulp, etc. kinds of loads. people's logic has gotten severely flawed somewhere if they think that higher rpm = lower fuel mileage on a loaded truck.

Those numbers that you posted clearly shows that it is over-boosting .. and it is most likely that the engine is labouring against its own exhaust gasses all the time due to an over-spooled turbo when in higher rpm ranges. An engine that does this will have significantly lowered fuel efficiency because the turbo is choking the exhaust all the time unnecessarily.


RE: tuning question - ptlogan77 - 05-14-2022

Wow.

You are a piece of work.

16th gear or 7th high, whichever you want to call it is 1:1 on a RTLO18918B transmission. PERIOD.

AND I never said that higher rpm equals less MPG.

I was stating what MY ENGINE IS DOING NOW, not what it will do or how it will perform after it is properly tuned by someone who's arrogance doesn't keep them from making suggestions based on the given input, and not trashing them.

I understand that you are an experienced Cummins man and am not here to bash your knowledge.

i see no reason for you to bash me or the truck I own.

I only asked for some help. Your opinion on my equipment is not necessary.

I only asked for tuning help.

If my engine is over boosting, then obviously I could benefit from a proper tune.

If you or another forum member feel that this is something they could look into, I would appreciate the help.

As far as telling me about my flawed logic when I never stated such a theory, or bashing the equipment I own for no reason other than to prove to yourself that you are cool is at the least counter productive and at best confrontational rather than in any way helpful.


RE: tuning question - Rawze - 05-14-2022

(05-14-2022 )ptlogan77 Wrote:  Wow.

You are a piece of work.
...

I am not bashing you.. I am pointing out the flaws in the ideas that people get themselves caught up into... to which you seem to have found yourself in. And yeah.. I am full of hot-sauce and passion sometimes. That is who I am because I have a drive for dispelling the irony of it all. Read what I am saying.. and try to learn from it, it is meant for people to open their eyes and listen to reality towards making themselves as profitable, and their equipment as trouble-free + fuel efficient as possible long term. Apply what I am telling you to your equipment .. and you will benefit from starting to know better when looking into the future so that wiser business decisions can be made.

We live in the age of modern trucking.. where engines are inherently over-designed, computerized, etc.. but this does not mean that a person cannot make them profitable, reliable, and to use those newer designs to benefit them instead of it working against them. - That is what I am getting it, but it takes doing the things that I mention to achieve it, and not listening to the morons out there who are so quick to excuse themselves away from reality.

I said what is wrong very clearly, and how to keep at bay, those kinds of issues that you will inevitably encounter in the future if noting much is done. Last I checked, I wanted my own engine/truck to last a million miles between inframes/overhauls, not half that and then have to pour moneys into it every few years because it was geared to tall, worked to hard, and then abused by bad de-mandate programming ... which is exactly what is wrong with the trucking industry as a whole. This especially up in the northwestern areas where you say that its driven and even more-so up in canada where it is an absolute, out of control plague.

Copy the program out of the ecm and send it to me for a proper review. There is no sense at all in asking about 'tuning' on things, or adjusting stuffs if the program is already horrible to begin with.

And if you want to run it down the roads with it geared to tall.. that is your own prerogative. i choose to point it out so that other people reading about this stuffs can make wiser decisions on the subject ... but about 3 years or so from now (if not sooner), when it needs another inframe in half the expected time again, a person cannot say that they were not warned about reality of how it was spec'd and what its outcome will almost always be. Don't blame the engine when it goes south 2x more often that normal, and cannot hardly get out of its own way when heavy, blame the person who would order a truck like that with those garbage-can rear ends to begin with.


RE: tuning question - ptlogan77 - 05-14-2022

I agree on the gearing... I'd prefer 3.73's all day long, but my previous trucke burned to the ground 3 weeks before last year's crab season started up north so I was in a pickle and bought the best of what was available in short notice.

I have ordered an Inline 6 adapter, that will be here on Monday,.

Which programs do I need to install?

I have Windows10 and TeamViewer. Pretty much a Clean hard drive other than that.