Ford vs. GM: Twin-Turbo Showdown

[Ford850]

The best way to measure the power is to hook up a trailer and hit the road. You'll notice no owners questioning the EB power in real world use. Of the small percentage of guys that have issues with the EB intercooler, most still say they would buy another one because the low end power is intoxicating and cannot be matched by any brand. I'm sure GM is targeting that low end power niche, or will be very soon.

 

[Dmace]

I used the word "claiming" for the GM motor as well.

Yes but if GM's claim is more realistic than Ford's claim then your unfairly comparing the two stating "Obviously ford tuned the ecoboost for lower rpms thus a larger hit on the HP". If GM's engine proves to meet that 90% at 2500 like Ford's 90% at 2300 then the GM wins by nearly matching it plus 55 more HP as well.

 

[Dmace]

The best way to measure the power is to hook up a trailer and hit the road. You'll notice no owners questioning the EB power in real world use.

It takes more than an engine to show real world measures. That "low end power" could be more a result of gearing than engine power. For instance, take two similar trucks (same engine, layout, transmission, etc...) but one with a 3.73 rear end and one with a 4.10. The one with the 4.10 will feel like it makes a TON of "low end power" when in reality it's making the same as the other. The difference is in the gearing...

 

[jejeosborne]

It takes more than an engine to show real world measures. That "low end power" could be more a result of gearing than engine power. For instance, take two similar trucks (same engine, layout, transmission, etc...) but one with a 3.73 rear end and one with a 4.10. The one with the 4.10 will feel like it makes a TON of "low end power" when in reality it's making the same as the other. The difference is in the gearing...

How do you explain my tachometer at 2000 rpms, speedometer at 70 mph, transmission in 6th gear, torque converter locked, large long hill, and no downshift or unlocking of torque converter all while towing 5000 lbs? Happened to me several times today.

Yes but if GM's claim is more realistic than Ford's claim then your unfairly comparing the two stating "Obviously ford tuned the ecoboost for lower rpms thus a larger hit on the HP". If GM's engine proves to meet that 90% at 2500 like Ford's 90% at 2300 then the GM wins by nearly matching it plus 55 more HP as well.

The Ford number is 1700 rpms. Remember we are talking comparable at the crank.

 

[Dmace]

How do you explain my tachometer at 2000 rpms, speedometer at 70 mph, transmission in 6th gear, torque converter locked, large long hill, and no downshift or unlocking of torque converter all while towing 5000 lbs? Happened to me several times today.

5,000 lbs, really? Light loads don't require much downshifting, was that your huge camper? :laughing:

The Ford number is 1700 rpms. Remember we are talking comparable at the crank.

Power from the crank to wheels is linear so 90% at the wheels is 90% at the crank. The number's different but it's still not making 90% of that number until 2300 rpms. It's pretty simple, IF the GM engine can produce 90% of it's power to the wheels at 2500 RPMs then their claim is truthful.

Ford claims 90% TQ at 1700 RPMs.
90% of 420 = 378 - 14% drivetrain loss (53 lb.ft.) = 325 lb.ft at the wheels which occurs at around 2,300 RPMs according to the most accurate dyno I've seen yet...

 

[aczlan]

Keyword here is "claiming". Ford's claim was already proved wrong...
It didn't make 90% of it's torque until about 2300 rpms. At 1700 it made about 70%, certainly nothing to complain about but stop comparing "claims"....
How We Dyno Tested Ford's 3.5-liter EcoBoost V-6 and 5.0-liter V-8 Engines - PickupTrucks.com News

And you have jumped to conclusions. A Chassis dyno is not an Engine dyno and they will have different results especially with a transmission that plays with the torque converter to help with boost.
OEMs have been using higher stall speeds in their torque converters since the 7.3 and 5.9 were new (as explained by Banks):

Unlike gas engines, diesels develop massive amounts of torque (pulling power) at low RPM – enough that it's possible (and, in fact, desirable) to get a heavily-loaded diesel truck rolling by simply easing off the clutch without touching the accelerator. Banks' dynamometer tests show that Ford's 7.3 liter Power Stroke hits peak torque at 1,600 RPM and begins to drop off at around 1,850 RPM, while the Dodge's 5.9L Cummins engine peaks at 1,400 RPM and drops off at 1,800 RPM. As RPM continues to rise, torque decreases even further.
How would you translate this to a torque converter? With a low stall speed. But both the Ford and Dodge torque converters stall between 2,000 and 2,500 RPM – so with a heavy load, the torque converter won’t start turning the rear wheels until well beyond the engine's torque peak. In this case, the stall speed is too high - it is literally impossible to get the engine's full power to the rear wheels! In order to access all of the engine's potential power, the stall speed must be lowered.

They might also be using that to limit torque to the drivetrain for some reason, or to make it easier to bump the HP/TQ at the wheels for later year with just a reflash...

Aaron Z

 

[Dmace]

If that's true in this case then what's the point of that low end Torque if it doesn't make it to the ground?
Bragging rights? Do they bring a copy of the Engine Dyno to poker nights?

 

[jejeosborne]

5,000 lbs, really? Light loads don't require much downshifting, was that your huge camper? :laughing:

Power from the crank to wheels is linear so 90% at the wheels is 90% at the crank. The number's different but it's still not making 90% of that number until 2300 rpms. It's pretty simple, IF the GM engine can produce 90% of it's power to the wheels at 2500 RPMs then their claim is truthful.

Ford claims 90% TQ at 1700 RPMs.
90% of 420 = 378 - 14% drivetrain loss (53 lb.ft.) = 325 lb.ft at the wheels which occurs at around 2,300 RPMs according to the most accurate dyno I've seen yet...

Yes, 5000 lbs and yes camper with 3 motorcycles and a 4-wheeler in the bed of the truck which I didn't include earlier. Why is this funny? I kept thinking to myself, surely it will downshift on this hill, but it didn't. Just let it stay on cruise control and on we went. Just pointing out that I am at 2000 rpm at 70 mph and I have been conditioned in the past to expect downshifts. It is something that amazes me and haven't been accustomed to. No humor meant so not sure why it struck you that way.

Again, start researching how difficult it is to dyno a turbocharged drivetrain on a chassis dyno. Let google be your friend.

Btw, I sold my 32' camper a year ago and now enjoy my self made toy hauler from a high wall popup. You must have seen my build thread. I have never called it huge so you must just being smart ace. It is 26' ball to bumper and about 7' tall. Here is the link: http://www.tractorbynet.com/forums/showthread.php?t=237522

 

[Dmace]

Yes, 5000 lbs and yes camper with 3 motorcycles and a 4-wheeler in the bed of the truck which I didn't include earlier. Why is this funny? I kept thinking to myself, surely it will downshift on this hill, but it didn't. Just let it stay on cruise control and on we went. Just pointing out that I am at 2000 rpm at 70 mph and I have been conditioned in the past to expect downshifts. It is something that amazes me and haven't been accustomed to. No humor meant so not sure why it struck you that way.

It struck me as funny because 5000lbs won't make any decent truck downshift much, the fact your truck didn't is not exactly impressive which is obviously what you were going for. The real funny part is it's a pop-up which means very little aerodynamic drag making the load even easier. Also, I thought they were dirt bikes (200lbs +/-) but "motorcycles" does sound heavier.

On a side note, even my 9 year old 5 speed truck runs about 2000 RPMs at 70mph.

 

[aczlan]

If that's true in this case then what's the point of that low end Torque if it doesn't make it to the ground?
Bragging rights? Do they bring a copy of the Engine Dyno to poker nights?

Superb question. Perhaps you should email Ford and ask? I suspect that it is because every vehicle is a compromise between Engineering, Marketing, Warranty and governing bodies (ie: EPA, CARB, NHTSA, etc).
If you get a answer from Ford, perhaps (while you are on a roll) you could ask Dodge when they will get around to making a body that doesn't rust out the rocker panels in 8 years/80k miles...

Aaron Z