Peak torque question....

[craiggo]

I've read in several places where the peak torque in the 6.4 is around 2K. Assuming this is true, does anyone have any insight as to why this was done? Is it a bi-product of the 2-turbo set up or is there some other reason. At fist I balked at it but, now I'm thinking it may not be such a big deal? I can't get any other info on this so I was hoping for a discussion thread.

Craig

[JKitterman]

The International MaxxForce 7 is published as "The MaxxForce 7 diesel engine will power Class 5 through Class 7 trucks with 200-230 hp at 2,600 RPM and 560-620 ft. lbs of torque @ 1,400 RPM." from the International website http://www.maxxforce.com/products/de...amp;itemid=002

If the peak is around 2k, I would think it is related to the automatic transmissions it is normally paired with in the Ford.

[magnus1]

MaxxForce™ Diesel Engines for Class 6–7 Trucks

MaxxForce™ 7
Featuring a high-pressure common-rail fuel system utilizing Piezo-actuated injectors and an advanced air management system, the MaxxForce™ 7 engine provides exceptional fuel economy, power, performance, reliability and durability, while meeting the EPA’s stringent 2007 EPA emissions standards.

Fuel Economy
The new V-8 platform has had more than 80,000 hours of engine testing and 6 million miles of development and validation, the results of which show impressive numbers. Thousands of hours of dynamometer testing the results of which demonstrate an exceptional improvement in fuel economy over its predecessors. By optimizing transmission and drivelines it is possible to see double digit improvements in vehicle fuel economy with the MaxxForce 7. This is where the value of an integrated truck and engine company pays off for the customer. International has the ability to optimize its vehicles to achieve economy and provide these advantages and benefits to its customers.

High-Pressure Common Rail with Piezo-Actuated Injectors
Helping drive the fuel economy improvements is a high-precision, high-pressure common-rail fuel system that utilizes Piezo-actuated fuel injectors. The Piezo-electric linear actuator is a solid-state ceramic actuator that converts electric energy into linear motion precisely controlling the needle’s opening and closing through the hydraulic circuit. These actuators, the fastest in the industry, allow for precise control of five independent injection events per cycle. This capability, and the ingenuity of International's development engineers result in an engine with:

Outstanding performance
Great Fuel Economy
Low noise
Low emissions
Aftertreatment control without external dosing
Advanced Air Management
Working in conjunction with the common-rail fuel system is an air-management system utilizing an electronically controlled variable geometry turbocharger (EVRT™). The EVRT employs a set of vanes that automatically adjust to optimize the airflow within the turbo to provide exceptional response over a wide range of engine speeds for impressive acceleration, grade climbing and towing capability, and high-altitude performance. It also drives EGR for emissions control and is tuned to reduce noise, improve fuel economy, and make the International and IC vehicles the MaxxForce 7 powers responsive and driver friendly. It also drives EGR, delivers more air at lower RPMs and reduces parasitic loads in low or no load conditions. All of this helps to reduce noise, improve fuel economy, meet emissions and make the International trucks the MaxxForce 7 powers responsive and driver friendly.

Other features behind the reliability, durability and performance of the MaxxForce 7 include:

Parallel cooling optimizes the cooling of critical components versus using series-cooling loops. The parallel system used on the MaxxForce7 allows dedicated coolant flow to each critical component providing even cooling, which equates to long component life.
Directed Piston Cooling Jet Tubes and gallery cooled pistons, a big-bore feature incorporated into the new engine, distribute cooling oil into a passage surrounding the combustion bowl to remove the maximum amount of heat from the piston. This helps to achieve maximum durability and reliability and assure outstanding power and cylinder life in the face of higher firing pressures.
A single ECM with 32-bit processor provides powerful electronic control of the engine and aftertreatment systems and is vertically integrated to provide efficient communication with International’s trucks.
Top-mounted oil filter provides for ease of service and low cost of maintenance and ownership by allowing for quick and easy removal of the innovatively designed cartridge, which keeps oil self contained during a filter change, preventing dripping oil during routine maintenance.
Hydraulic lifters give the MaxxForce 7 a service-free valvetrain, eliminating the need to ever get under the valve cover.
The MaxxForce 7 diesel engine will power Class 5 through Class 7 trucks with 200-230 hp at 2,600 RPM and 560-620 ft. lbs of torque @ 1,400 RPM.

Specifications
Configuration: V8
Displacement: 6.4L (390 cu in)
Power Output: 200-230 hp (149 - 171 kW) @ 2,600rpm
Peak Torque: 560-620 lb. ft.(759 - 840 N m) @ 1,400rpm
Aspiration: Turbocharged
Combustion System: Direct Injection
B10/B50 Life: 262,500/375,000 miles
Dry Engine Weight: 1,150 lbs.

[Musclford]

So does tht mean Great fuel economy for the Ford Trucks too?

I haven't heard that much about great fuel economy until that post...

Musclford

[craiggo]

Well now I'm even more confused because this says:
The MaxxForce 7 diesel engine will power Class 5 through Class 7 trucks with 200-230 hp at 2,600 RPM and 560-620 ft. lbs of torque @ 1,400 RPM.

Peak torque at 1400?

My big question still remains unanswered, does any of it really matter?

[MonkeyBoy]

No, because the programming that Navistar uses isn't what Ford uses. They are two different brains that work with the same body.

[mudguppy]

the only thing that really matters is how well the transmission is matched/tuned for the engine's output. whether an engine is a rev'er or a lug'er, the tranny should be built/programmed to transfer the power and shift at the right rpms with respect to the powerband.

now, if it's a manual, then it's up to the driver.... [img]/ubbthreads/images/graemlins/wink.gif[/img]

[jesshwarren]

[ QUOTE ]
No, because the programming that Navistar uses isn't what Ford uses. They are two different brains that work with the same body.

[/ QUOTE ]

What these guys are saying is. Ford may have the max tq at 2k but the motor is capable of making max tq at 1400RPM with different programming.

[AllOutFirefighter13]

[ QUOTE ]
What these guys are saying is. Ford may have the max tq at 2k but the motor is capable of making max tq at 1400RPM with different programming.

[/ QUOTE ]

<font color="blue"> You think that would help with fuel mileage a bit?

Later, </font>

[COBRAJET]

Keep in mind we are talking MAX figures. The INTL version does not make the peak numbers that the PSD does....ie 350/650. The engine is tuned a little differently for maximum longevity in a class 5-7.

The Ford version makes more horsepower and torque. Everthing I have read has the motor making 500lbft right off idle. I am sure by 1400RPM it is producing the 560-620 that the IHC is. It simply goes on to make more by 2000K due to the tuning. We are not being shortchanged, simply given a "better" tune for a truck that is driven empty by the majority of its users most of the time.

[craiggo]

Found this yesterday that claims this 2000rpm is a tune specifically designed for towers???

http://www.prdomain.com/companies/F/...6121938143.htm

"With the diesel, for instance, we maximized torque at around 2,000 rpm," Poore said. "When our customers are hauling big loads they need more torque at low speeds to move quickly off the line."

[AllOutFirefighter13]

<font color="blue"> Yea, but I'm kinda in the same boat as a lot of folks. I'd like a little less horsepower in exchange for a longer, more reliable life of the engine. The version of the 6.0L bible I have says that at 1,500 RPM, my truck is making 500 ft-lbs of torque, with peak torque coming in at 2,000 RPMs. That is a considerable amount of pulling power but still too high for my liking. I've been thinking lately a lot about this very same thing we are talking about, and no offense to them, but how come the companies that make tuners, chips, etc. (SCT in particular) haven't come out with a "tune" that can mimic the same numbers as those 6.0Ls in Class 5-7 trucks. I'd for dang sure buy one. I bought this truck for pulling, not racing. I don't need to ring the crap out of it just to make numbers. I'm not saying that I haven't had a WOT pass here and there, though. They are fun to drive, but if going a little slower is worth fuel mileage and longevity, I'd rather have everyone else pass me up b/c they can. Just my $.02 worth!

Later, </font>

[IBUILD]

[ QUOTE ]
<font color="blue"> Yea, but I'm kinda in the same boat as a lot of folks. I'd like a little less horsepower in exchange for a longer, more reliable life of the engine. The version of the 6.0L bible I have says that at 1,500 RPM, my truck is making 500 ft-lbs of torque, with peak torque coming in at 2,000 RPMs. That is a considerable amount of pulling power but still too high for my liking. I've been thinking lately a lot about this very same thing we are talking about, and no offense to them, but how come the companies that make tuners, chips, etc. (SCT in particular) haven't come out with a "tune" that can mimic the same numbers as those 6.0Ls in Class 5-7 trucks. I'd for dang sure buy one. I bought this truck for pulling, not racing. I don't need to ring the crap out of it just to make numbers. I'm not saying that I haven't had a WOT pass here and there, though. They are fun to drive, but if going a little slower is worth fuel mileage and longevity, I'd rather have everyone else pass me up b/c they can. Just my $.02 worth!

Later, </font>

[/ QUOTE ]

Or why not make a tune that's adjustable. It would have a setting to derate the current power to perform more like the MAXXFORCE 7 , have a stock seting, and then maybe a race setting.

That way you could have it all. [img]/ubbthreads/images/graemlins/wink.gif[/img]

[AllOutFirefighter13]

<font color="blue"> Yup, that would be the best option for me. I wouldn't mind the tunes for racing, but I spend 99% of my driving with respect for longevity. Good idea!

Later, </font>

[v8440]

2000 rpm does seem kinda high for towing applications, especially when you have two turbos to help make it. It may be that the transmission will have a very steep 1st gear and/or a loose converter. Those things would make really low rpm torque less of a big deal.

I know that on the dodges, the cummins is supposed to start making peak torque at 1600 rpm, and carry it to somewhere into the low 2000's. With the automatic the 1600 figure is completely useless. The damn torque converter stalls at 2200 or so on a stone stock truck, thereby effectively lopping off the first 600 rpm of good torque production. Way to go dodge!!!