R&L | New Truck speed / Turbos

For those of you who do not know how a new engine works!

The newer engines do not run at the high rpm's like the old engines do. All of the mack engines are designed to run at their peak between 13 and 1500 rpms, unlike the old Detroit engines that run their best from 15 to 1800. This will give you 350hp. When you go any higher on the rpm's, the hp decreases by 10hp for every 100 rpm's you go above that. The trucks have all of the HP and Torque that they came from the factory with, you just need to learn how to drive it. The torque curve runs between 11 and 1400 rpms. If you shift the truck at a lower rpm, you will use more of the torque the engines has. It gives you 1460lbft of torque at 1100 rpm's. When they have cut the speeds back on the trucks, they have not cut the power away from it, they have made it so you can drive it to get the most power from it. The trucks were designed to run at their peak between 65 and 68mph. That is what they are geared for, not 72. I know taking 30 minutes more per day is coming out of your pocket, but the company has never had a lay off, and they have given raises every year for the last 5 or 6 years that I can remember. That should mean something, you could be working for someone like Jevic or Alvin....
 
The newer engines do not run at the high rpm's like the old engines do. All of the mack engines are designed to run at their peak between 13 and 1500 rpms, unlike the old Detroit engines that run their best from 15 to 1800. This will give you 350hp. When you go any higher on the rpm's, the hp decreases by 10hp for every 100 rpm's you go above that. The trucks have all of the HP and Torque that they came from the factory with, you just need to learn how to drive it. The torque curve runs between 11 and 1400 rpms. If you shift the truck at a lower rpm, you will use more of the torque the engines has. It gives you 1460lbft of torque at 1100 rpm's. When they have cut the speeds back on the trucks, they have not cut the power away from it, they have made it so you can drive it to get the most power from it. The trucks were designed to run at their peak between 65 and 68mph. That is what they are geared for, not 72. I know taking 30 minutes more per day is coming out of your pocket, but the company has never had a lay off, and they have given raises every year for the last 5 or 6 years that I can remember. That should mean something, you could be working for someone like Jevic or Alvin....

Check the actual dyno tests,not the manufacturer B.S., Your numbers are out of line. 2006-2008 mack aset engines,upper shift points 1800-1900rpms. down shift @ 1400-1500 rpms,it all the power the trns /motor combo can put out.
Remember it's not only the motor your dealing with, it's also the mismatched trans/rear combo R&L uses...
 
The upper shift points can't be at 18-1900 rpms when the engine is only rated for 1800. When you place the engine, trans, and rears in any engine manufacturers computer, you will find that it is the best combination for fuel economy, and gradability. Yes you can get a combination that will get you better gradability, but you will suffer fuel economy. You are way off with your 1800 upper shift points and 1400 lower. All you will be doing with that is blowing fuel out the stack. Like I have said, some people are open to the idea of a new engine, and some still believe you have to hold it to the floor untill it hits the governor.
 
Are we both sure were talking the same trucks,,,MAcks???
They are 2150 rpm motors,over speed at(and can vary per company spec's) 2350rpm. You seem to be quoteing the manuals,(I am refering to actual dyno tests)take one out in the hills and try both rpms. Running the current motors to 1100 rpms is ALOT more detrimental.
Can we maybe agree on one thing,, the final gear ratio is all wrong for the northeast.
 
Your truck will rev that high? The one stack mack with a heart attack assigned to me will sit at 1600 rpms until I get bored and shift it..

There is a road speed limiter for the top one or two gears,per R&L specs. Nothing to do with the motor. If it happens in the lower gears you got one sick dog...
 
We have slower trucks now,so that means
more time to do our jobs.What to do?As long as our checks are in our hands every week
do it really matter.:1036316054:
 
come on 2nd shift don't talk that sh%t, I can't afford to get anymore frt back any later then it gets to the barn now!!
Still stripping frt out tonight at 10:30pm. Complete joke!!! My last cuts are 10:30, what to do? Peace
 
Are we both sure were talking the same trucks,,,MAcks???
They are 2150 rpm motors,over speed at(and can vary per company spec's) 2350rpm. You seem to be quoteing the manuals,(I am refering to actual dyno tests)take one out in the hills and try both rpms. Running the current motors to 1100 rpms is ALOT more detrimental.
Can we maybe agree on one thing,, the final gear ratio is all wrong for the northeast.

Yes they will run 2150 and sometimes 2350, but the actual operating range ends at 1800. It is no different than the engine in your car, it will run up to 8,000rpms, but it will not do you any good after the operating range. Do you always shift your car at it's max rpms? Yes, I will agree the trucks are not the correct trucks for mountains, but not because of the gearing, but because of the motor. When you look at the current combination, the gearing is fine, it is the engine that needs to be a little bigger. You are getting everything out of the engine that is possible. If you gear the truck with a lower gear, that will only cause you to run higher rpms, which take you back to the original argument, lower rpms = more torque. Torque = pulling power. Listen to the guys running Corn binders, they will tell you their trucks pull fine. It is the same exact gearing, just with another 100 lbft torque, and 35 more HP.
 
butting in...

My barn has replaced a lot turbos in the last 2 weeks... shop foreman said the turbos are failing due to the power being cut back to much. I am currious if anyone else see this as a trend? (its been on all the PT series macks)
don't know if this has anything to do with it... I smoked a turbo on a (very new) volvo last week in Harrisburg PA. (never smoked one in my 10 years of driving...
 
He drives for Yellow Big$.I agree with him and not the shop Foreman in the other post.Been with R&L 5 yrs and we had turbos going on the 04's when they were new and that was well before they started this cutting down crap.
 
I have to agree with the hooker here, as much as it pains me because I think he's one of the many company snitches that abound on this website. I did notice that he changed his location. Nice try buddy, too little too late.

Anyway, I run my PS between 11 and 1500 and it pulls fine, even with a heavy set. I can't really complain.
 
Enough of this for me, almost ten years at mack,(fully trained on EVERYTHING mack). And you now want to compare different motors.
I have talked to upper management inWIL about the trucks (back in 1999), no one listened. And now with bigger fans and EGr systems it is a worse problem than it was then.
I have been working in this field far too long to discuss this further,believe what you like...
THE TRUTH IS OUT THERE......:1036316054:
 
Enough of this for me, almost ten years at mack,(fully trained on EVERYTHING mack). And you now want to compare different motors.
I have talked to upper management inWIL about the trucks (back in 1999), no one listened. And now with bigger fans and EGr systems it is a worse problem than it was then.
I have been working in this field far too long to discuss this further,believe what you like...
THE TRUTH IS OUT THERE......:1036316054:
I agree with what you have stated Mechanix, I used to work them and now try to drive them , but apparently some Desk jockey believes all the crap they feed them . These Macks are not meant in any configuration to be run on the East coast, but hey we musta got a DEAL :biglaugh:
 
There is a road speed limiter for the top one or two gears,per R&L specs. Nothing to do with the motor. If it happens in the lower gears you got one sick dog...
Why the limiter???????????

Also all the Macks were for the west coast but for some reason they didn't get sent(just a rumor i heard)
 
Like I have been saying, some people are open to change, and some are not. No, I'm not one of those snitches, I have driven all of the different trucks, worked on all of them, and towed a sh*t load of them from all over the country. Overall the best trucks we have is the cornbinders, but we have to make do with what we have. What I am trying to get through to some of you is that if you try driving the truck differently, you might find out what many others have found. Change is not always bad.
 
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