Forum Discussion
- AH64IDExplorer
RCMAN46 wrote:
I am sure the Eco had gears left.
Do the math on the gears.. It didn't. 4K rpms is what it was running in 3rd at 65 to hold speed, but not accelerate.
The ratio on 2nd means it would have been above redline on a downshift, that means it was out of gears for that speed.FishOnOne wrote:
The EcoBoost waxed the 6.2 V8 because of the altitude of the test. Dyno test's performed in Denver on a NA V8 shows how bad HP is affected.
I guess I don't see how you guys think it waxed it??
It was 0:11 slower, and ran into traffic that slowed it down for more than enough of that time.
The 6.2 had power to spare at the top and the EB didn't, that right there negates any waxing.
FWIW: Neither vehicles is in my future, especially as a TV... so I really don't care who wins. I simply didn't see anything showing the EB waxing the 6.2, not even close. Turtle n Peeps wrote:
The Lincoln waxed the GM on the Ike whether anybody wants to admit it or not.
Here is the math to show how this works out.
The GMC comes with a 420 HP NA engine. The standard formula for altitude lose is 3%/ 1000 feet. The Ike tunnel is 11,000 up. I don't know what the climb is from A to B is but lets just say it's an average of 10,000 for round figures. The math says the 6.2 WILL lose over 120 HP at that altitude! That brings the potent 6.2 down to an impotent 300 HP. That's why the Cheby was shifting over and over and over again. It was trying to keep the engine in the power band because it needed all of that 300 HP it had.
Now for the twin snail engine.
The EB is reported to put out 380 HP in this vehicle. Since most turbo engines have extra air to put out they lose very little HP if any. So as anybody can see, the EB is going to have a 80+ HP advantage.
Another advantage is this engine can pump a lot of air at a low RPM giving it a wide flat curve.
Another thing to think about is the weather. The 6.2 would have a very hard time pulling up that mountain if it was 90 degrees out. Air density would have been way down. The GMC really got an advantage when towing in this type of weather.
The EcoBoost waxed the 6.2 V8 because of the altitude of the test. Dyno test's performed in Denver on a NA V8 shows how bad HP is affected.- RCMAN46ExplorerThe Eco waxed the 6.2.
Someone must have watched different videos than I did.
The Eco was not out of gears. The video shows many shots of the speedometer and the tachometer.
On the Eco most showed a speed greater than 60 mph and rpm's in the 3000-4000 range.
I am sure the Eco had gears left.
Both vehicles were able to pull the grade for the most part at the speed limit and had reduced throttle to stay below the speed limit.
The 6.2 always had power to spare to accelerate on demand. There were several places the ECO was not able to accelerate.
The main reason the 6.2 was gear hunting is the driver was throttling back to stay below the speed limit. When this was done there was a resultant gear change. Then the driver would notice a drop in speed and feed too much throttle thus a drop in gearing. Most of the gear changing was due to the driver. Had he used the cruise control I suspect there would have been much less gear changing.
But gear changing is not a bad thing. That is the whole purpose of a transmission. In the future we are going to see 8 and 10 speed transmissions if not CVT's if they can get the torque capabilities need for towing.
Watch how often the big rigs change gears on the same run up to the tunnel. Some of them have close to 20 gears to choose from and a good truck driver will use them to keep the engine in its power band.
The fact both were able to climb the hill at or above the speed limit not much was learned except the 3.5 ECO produces surprising power with almost 1/2 the displacement.
I would have preferred that they just engage the cruise control on both and let the computers take over. Comparing how both managed the hill with cruise control would have given me more what I would want to know.
About 95% of my towing in the West is done with the cruise control on. - AH64IDExplorer
Turtle n Peeps wrote:
The Lincoln waxed the GM on the Ike whether anybody wants to admit it or not.
Here is the math to show how this works out.
The GMC comes with a 420 HP NA engine. The standard formula for altitude lose is 3%/ 1000 feet. The Ike tunnel is 11,000 up. I don't know what the climb is from A to B is but lets just say it's an average of 10,000 for round figures. The math says the 6.2 WILL lose over 120 HP at that altitude! That brings the potent 6.2 down to an impotent 300 HP. That's why the Cheby was shifting over and over and over again. It was trying to keep the engine in the power band because it needed all of that 300 HP it had.
Now for the twin snail engine.
The EB is reported to put out 380 HP in this vehicle. Since most turbo engines have extra air to put out they lose very little HP if any. So as anybody can see, the EB is going to have a 80+ HP advantage.
Another advantage is this engine can pump a lot of air at a low RPM giving it a wide flat curve.
Another thing to think about is the weather. The 6.2 would have a very hard time pulling up that mountain if it was 90 degrees out. Air density would have been way down. The GMC really got an advantage when towing in this type of weather.
While I follow your logic I fail to see how the engine that was down on hp could accelerate and the one that wasn't couldn't, and how you think the EB waxed the 6.2. In summer it may have been different, but in this test the 6.2 was not waxed, as it had power to spare when the EB didn't.
If the EB had more gears it would have been shifting too. 65mph in 2nd is above redline, therefore a downshift wasn't going to happen until the vehicle slowed a bit. It had enough hp to hold, but not to accelerate. The 6.2 was accelerating.
Does anyone know the WG specs on the EB? I would be curious how much boost it runs, and how much it has to spare. Mid rpm range is the hardest range to make peak power at elevation as the turbo isn't always running against the WG at WOT like it would be at rated rpm.
I don't think they mentioned GVW, so I wonder how close they were?? Shipping weight is close, but options can add quite a bit.
Math is one thing, actual results are another.
Gearing is huge when your getting power to the wheels. We know how much power the 6.2 loses at elevation, but the amount lost by the EB is an unknown. If the EB didn't lose any, unlikely, then Ford needs to work on gearing. - Turtle_n_PeepsExplorerThe Lincoln waxed the GM on the Ike whether anybody wants to admit it or not.
Here is the math to show how this works out.
The GMC comes with a 420 HP NA engine. The standard formula for altitude lose is 3%/ 1000 feet. The Ike tunnel is 11,000 up. I don't know what the climb is from A to B is but lets just say it's an average of 10,000 for round figures. The math says the 6.2 WILL lose over 120 HP at that altitude! That brings the potent 6.2 down to an impotent 300 HP. That's why the Cheby was shifting over and over and over again. It was trying to keep the engine in the power band because it needed all of that 300 HP it had.
Now for the twin snail engine.
The EB is reported to put out 380 HP in this vehicle. Since most turbo engines have extra air to put out they lose very little HP if any. So as anybody can see, the EB is going to have a 80+ HP advantage.
Another advantage is this engine can pump a lot of air at a low RPM giving it a wide flat curve.
Another thing to think about is the weather. The 6.2 would have a very hard time pulling up that mountain if it was 90 degrees out. Air density would have been way down. The GMC really got an advantage when towing in this type of weather. - mich800Explorer
ib516 wrote:
We'retheRussos wrote:
Home Skillet wrote:
You use premium fuel for max horsepower.
With the lower octane fuel, the power is reduced.
Incorrect. The Octane level determines the amount of pressure the fuel can withstand before it detonates. Higher performance / turbo charged engines like the EcoBoost have high compression ratios and therefore require a high octane fuel to prevent knocking. Using a low octane fuel can cause knocking and possibly damage to the engine.
On engines that require 87, they have lower compression ratios and therefore its not beneficial to put in a higher Octane. People read "Premium" and go for the marketing when it does absolutely nothing - if anything there are tests that show your MPG will go down slightly by using a higher octane fuel than recommended because your engine is not able to ignite the fuel at the opportune time.
In a non-direct injected engine, the above theory is correct. Not sure the same applies to DI engines. That is the reason DI exists. Check out the compression ratio on a Mazda Skyactiv engine. 13:1 on 87 octane, because it has DI.
Also with today's variable timing and knock sensors the tuning can adjust for quality of fuel. So the old school of tuning for one specific octane or quality of fuel does not apply. - ib516Explorer II
We'retheRussos wrote:
Home Skillet wrote:
You use premium fuel for max horsepower.
With the lower octane fuel, the power is reduced.
Incorrect. The Octane level determines the amount of pressure the fuel can withstand before it detonates. Higher performance / turbo charged engines like the EcoBoost have high compression ratios and therefore require a high octane fuel to prevent knocking. Using a low octane fuel can cause knocking and possibly damage to the engine.
On engines that require 87, they have lower compression ratios and therefore its not beneficial to put in a higher Octane. People read "Premium" and go for the marketing when it does absolutely nothing - if anything there are tests that show your MPG will go down slightly by using a higher octane fuel than recommended because your engine is not able to ignite the fuel at the opportune time.
In a non-direct injected engine, the above theory is correct. Not sure the same applies to DI engines. That is the reason DI exists. Check out the compression ratio on a Mazda Skyactiv engine. 13:1 on 87 octane, because it has DI. - N-TroubleExplorer
RCMAN46 wrote:
rjstractor wrote:
It should be noted that the two engines were not rated at the same horsepower, IIRC the 6.2 has 420 and the Eco has 380. It seems as though they were pretty evenly matched although the 6.2 with the 8 speed seemed to be constantly shifting. That would make me crazy.
That is the whole idea behind the 8 speed and there is a 10 speed out there.
A transmission that has many close ratios will allow more gear shifting to keep the engine rpm in it's max power range. Also allows the use of tall rear end ratios which will give better economy at light loads.
Possibly one reason the GM did better on fuel.
If you do not want gear changing we can go back to the old 3 speed transmissions of the 60's and 70's.
IMO current 6-speeds fit the sweet spot between good performance/economy without the annoyance of over hunting for gears. Once you go above 6-speed the annoyance factor goes up in a hurry while the beneficial returns become very diminishing at that point. Some people out there seem to always think "more" means better. Corporate marketing teams love these kind of consumers. - Paul_ClancyExplorerGears are also why the Eco ran out of power at the top.
- RCMAN46Explorer
rjstractor wrote:
It should be noted that the two engines were not rated at the same horsepower, IIRC the 6.2 has 420 and the Eco has 380. It seems as though they were pretty evenly matched although the 6.2 with the 8 speed seemed to be constantly shifting. That would make me crazy.
That is the whole idea behind the 8 speed and there is a 10 speed out there.
A transmission that has many close ratios will allow more gear shifting to keep the engine rpm in it's max power range. Also allows the use of tall rear end ratios which will give better economy at light loads.
Possibly one reason the GM did better on fuel.
If you do not want gear changing we can go back to the old 3 speed transmissions of the 60's and 70's.
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