De-Mandated CM870
05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #1
De-Mandated CM870
I've got little over 3k hrs on this motor since it was tuned (which was done right after a infarame) and I feel my EGT is a bit high and not putting out enough power. During a long pull it'll reach 1000 degrees put usually doesn't exceed 950 degrees. Cruising is around 750 degrees.
I'm constantly pulling heavy. Usually over 100k lbs and I'd like to get more power out of her without cracking liners if that's possible.
When I first bought the truck 7 years ago I had it de-mandated and the guy messed with my timing to get more powerout of her and like a fool I trusted him. Long story short I ended up with a cracked number 5
I'd appreciate any helpful advice so I can finally love this motor and stop hating it.
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05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #2
RE: De-Mandated CM870
Who did the latest tune, looks to me like you are cooking your motor. My best advice for you is to pull a file and send it to Rawze. My other advice, if your motor is still intact with the OEM bits still on it and not all hacked to pieces, is to take it to a dealer or shop and have the correct OEM program flashed on the ECM before it fails too.

Question, what are you driving? Gearing? Transmission, etc... What you are asking for sounds more like a gearing issue, not a HP or torque issue.


User's Signature: 2008 ProStar, OEM 600hp CM-871, 18spd, 3:42, in framed in Rawze's driveway. Every day is a fresh new episode of, "The Twilight Zone"... Rod Serling lives rent free in my head. I can smell the Chesterfields.
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05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #3
RE: De-Mandated CM870
Well I just upgraded my transmission for a 20918 cause I got a deal on it. Plus I wanted the heavier duty tranny for the power I someday put in front of it. My gearing is 3.91 on 24.5 wheels. The truck does alright with power. I would just like more. I had a tanker pulling doubles who had 30k lbs on me catch me in the hills. I was 135k lbs. I know their trucks are built for that kind of weight but I'd at least like to be able to keep up given the circumstances
.
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05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #4
RE: De-Mandated CM870
(05-04-2021 )Waterloo Wrote:  Who did the latest tune, looks to me like you are cooking your motor. My best advice for you is to pull a file and send it to Rawze. My other advice, if your motor is still intact with the OEM bits still on it and not all hacked to pieces, is to take it to a dealer or shop and have the correct OEM program flashed on the ECM before it fails too.

Question, what are you driving? Gearing? Transmission, etc... What you are asking for sounds more like a gearing issue, not a HP or torque issue.

Also a well trusted shop did my tune. The turbo was new when I bought the truck 7 years ago and so was the head. Still running them. All my parts are pulled from the motor. What do I need to pull a file to send to Rawze? And how?
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05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #5
RE: De-Mandated CM870
Take those tall 24.5's off put some low pro 22.5's on and you might actually realize those 3.91 rears will smoke 100k up a hill if you were so inclined to do so. If you need ground clearance for a DD trailer look in to a 5th wheel riser.

The reality of your situation is that your engine makes more than enough power to pull the weights you claim. We have a guy on here (Hammerhead) that is mega hauler (250k +) and I believe he does it day in day out with 550hp on a cm871. He simply geared and set up his truck to do the job he performs.
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 Thanks given by: Waterloo
05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #6
RE: De-Mandated CM870
just a warning for those reading...

-- WE DO NOT DO or ENCOURAGE BIG POWER ON HERE ... SO WHENEVER SOMEONE HAS SOME KINDA EGO ISSUES ABOUT "KEEPIN' UP WITH THE JONESES... AND GOTTA BE BIG-DAWG WHEN PULLIN' THE HILLS'' " KINDA ATTITUDE, THEY WILL SIMPLY GET KICKED OFF HERE! --- I DO NOT TOLERATE the SUPER-TRUCKER (STUPID-TRUCKER) ATTITUDE AROUND HERE ... PPL LIKE THAT ARE BETTER OFF STAYING ON THE SOCIAL MEDAI, WHERE THAT GARBAGE BELONGS!. I AM SURE THERE WILL BE PLENTY OF IDIOTS OVER THERE THAT SOMEONE LIKE THAT CAN BE HAPPY WITH!.

Hopefully, your not one of them.

This place is all about doing things right without taking a bunch of guessing and/or shortcuts, doing things towards best longevity, and long term profitability.

-- Pull a copy of the program out of that ecm and e-mail it to me for a review... That is the place to start with it, so that you know exactly what you have and stop guessing and making blind-man statements based on assumptions. If your programming is ok, the it will be seen as such in the review... If it is not then at least you will know the truth. - Just for an FYI: Nobody on here is trying to get anything from you, they speak from experience ... everything I do for others on here is for free.

NEXT... what is the boost doing when you get to in a hard pull?... how high can it go of you let it? .. What are the oil temps doing? .. and Does it have all the original hardware on it + VG turbo,... or has there been some hardware mods?... and what are they if any?


User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
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05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #7
RE: De-Mandated CM870
(05-04-2021 )AK Trucker Wrote:  
(05-04-2021 )Waterloo Wrote:  Who did the latest tune, looks to me like you are cooking your motor. My best advice for you is to pull a file and send it to Rawze. My other advice, if your motor is still intact with the OEM bits still on it and not all hacked to pieces, is to take it to a dealer or shop and have the correct OEM program flashed on the ECM before it fails too.

Question, what are you driving? Gearing? Transmission, etc... What you are asking for sounds more like a gearing issue, not a HP or torque issue.

Also a well trusted shop did my tune. The turbo was new when I bought the truck 7 years ago and so was the head. Still running them. All my parts are pulled from the motor. What do I need to pull a file to send to Rawze? And how?

Inline 6 or usb link 2 and calterm.
replyreply
05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #8
RE: De-Mandated CM870
(05-04-2021 )Chamberpains Wrote:  Take those tall 24.5's off put some low pro 22.5's on and you might actually realize those 3.91 rears will smoke 100k up a hill if you were so inclined to do so. If you need ground clearance for a DD trailer look in to a 5th wheel riser.

The reality of your situation is that your engine makes more than enough power to pull the weights you claim. We have a guy on here (Hammerhead) that is mega hauler (250k +) and I believe he does it day in day out with 550hp on a cm871. He simply geared and set up his truck to do the job he performs.

I'd agree with you there. But I run Alaska highways and have disc brakes. Spitting pads is more common than you'd think up here and when they do they cut the rim in half from what I've seen. It's doable but not ideal for our roads. I would like to upgrade to 4.11s on my ratio. But most trucks up here these days are running 600+ hp. When you're geared for 250+ lbs you're not really worried about speed or fuel economy so much. We run heavy ish and fast up here. I like to dial her back to about 60 mph since that's about the best fuel economy she runs at. It's all about physics and energy management.
replyreply
05-04-2021, (Subject: De-Mandated CM870 ) 
Post: #9
RE: De-Mandated CM870
(05-04-2021 )Rawze Wrote:  just a warning for those reading...

-- WE DO NOT DO or ENCOURAGE BIG POWER ON HERE ... SO WHENEVER SOMEONE HAS SOME KINDA EGO ISSUES ABOUT "KEEPIN' UP WITH THE JONESES... AND GOTTA BE BIG-DAWG WHEN PULLIN' THE HILLS'' " KINDA ATTITUDE, THEY WILL SIMPLY GET KICKED OFF HERE! --- I DO NOT TOLERATE the SUPER-TRUCKER (STUPID-TRUCKER) ATTITUDE AROUND HERE ... PPL LIKE THAT ARE BETTER OFF STAYING ON THE SOCIAL MEDAI, WHERE THAT GARBAGE BELONGS!. I AM SURE THERE WILL BE PLENTY OF IDIOTS OVER THERE THAT SOMEONE LIKE THAT CAN BE HAPPY WITH!.

Hopefully, your not one of them.

This place is all about doing things right without taking a bunch of guessing and/or shortcuts, doing things towards best longevity, and long term profitability.

-- Pull a copy of the program out of that ecm and e-mail it to me for a review... That is the place to start with it, so that you know exactly what you have and stop guessing and making blind-man statements based on assumptions. If your programming is ok, the it will be seen as such in the review... If it is not then at least you will know the truth. - Just for an FYI: Nobody on here is trying to get anything from you, they speak from experience ... everything I do for others on here is for free.

NEXT... what is the boost doing when you get to in a hard pull?... how high can it go of you let it? .. What are the oil temps doing? .. and Does it have all the original hardware on it + VG turbo,... or has there been some hardware mods?... and what are they if any?

Hey Rawze my boost is normal. Max out at 38 lbs. Averages around 32 lbs. I'll look into getting the program pulled and sent to you as soon as I can. All I have is a ELD plugged in so I'll have to order Inline 6 or something. I just had kenworth swap out injectors and now I'm getting constant 1000 degree Pyro temps and black smoke when I grab gears.
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