Buyers Remorse...I should have bought a...

[lnferno]

I don’t think that is true at all. Various sources give the Raptor a 0-60 time of 5.1 while the 3.5 eco boost F150 does 0-60 in 6.1 seconds.

https://www.youtube.com/watch?v=pJDVi0y-9xk

 

[Gargamel]

I have had my 2018 for a month now. If I was in your boat/altitude I would be looking at an F250 diesel or a Chevy 2500 diesel.

Exactly. Go get a diesel 250 or 2500.

OP - once you drive these, you will understand.

 

[ColoradoBoss]

im in the springs at 6200ft. i drive up the mountain 3-4 nights a week to approx 10k ft. never had a power issue, however im in a gen 1 so no ecoboost

Up the mountain to woodland? I'm in woodland. Also just to keep on topic. Forced Induction engines still lose power the same as an N/A engine.

 

[lnferno]

Up the mountain to woodland? I'm in woodland. Also just to keep on topic. Forced Induction engines still lose power the same as an N/A engine.

That’s absolutely not correct. Please do some research. Naturally aspirated vehicles are affected twice as much as turbod vehicles at Colorado altitude.

 

[ColoradoBoss]

That’s absolutely not correct. Please do some research. Naturally aspirated vehicles are affected twice as much as turbod vehicles at Colorado altitude.

School me then.

 

[lnferno]

School me then.

There are many articles written on this. This is just one of them...The only thing I disagree within this article is that you're not going to get sea-level performance out of a turbo up here at altitude, UNLESS you're talking about these crazy 1500+ HP cars like you see at the Pikes Peak Airstrip Attack last weekend (which I participated in BTW).

No matter what type of piston engine you are working with, engine horsepower is always dependent on the amount of fuel and air the engine burns. Keep in mind that it's the density of the mixture, not the volume that determines the power that the engine is capable of generating. Power is not a function of the volume of air, it's a function of the mass, or weight, of the air - the actual number of molecules entering the combustion chamber. This is an important factor to keep in mind when discussing turbocharging. Let's look at an example.

Let's assume a standard day, and we've got a 550-cubic-inch displacement engine at sea level. At sea level elevation, that engine will inhale 550 cubic inches of air for every two revolutions of the crank. It would also inhale around 550 cubic inches of air in Colorado, say at 5,500 feet altitude, on a hot day. But the actual number of air molecules entering the combustion chamber, and of course the resulting power, is going to be very different in these two examples. In Colorado, there's fewer air molecules at that altitude to support combustion than there are at sea level. The result is less power for the same volume of air.

The bottom line is this. We can only burn more fuel if we build a larger engine, or we artificially cause a small engine to breathe as if it were larger than it really is. And that's what we do with turbocharging. We cause a small engine to breathe as if it were a larger engine.

Let's go over a few principles of turbocharging. Keep in mind it's not only the cubic-inch displacement of the engine that it's rated at and its rated manifold pressure that determine the engine's performance. Power is also affected by the temperature of the air as it's swept into the cylinders. The temperature of the air greatly affects the density of the air. It's the weight of the air, not the volume, that produces the power.

Now at sea level, assuming a standard day, sea level air density is 0.0765 pounds per cubic foot whereas at 10,000 feet, on a standard day, air density drops to 0.0565 pounds per cubic foot. So in a naturally aspirated engine, let's say it's rated at 100 horsepower at sea level. It generates only 73.9 horsepower at 10,000 feet.

Why turbocharge?

So why do we bother turbocharging? Well, for the simple reason that power diminishes with an increase in altitude. How much manifold pressure is lost for every 1,000 feet of altitude gained? Most of you know the answer to that. It is approximately 1 inch for every 1,000 feet of altitude. And that calculates to around 3 to 4 horsepower lost for every 1,000 feet gained. Remember, power is inversely proportionate to altitude gained. Increased altitude comes with a price - loss of power. At about 18,000 feet, the air pressure and the oxygen molecules are about half that of sea level pressure and air density. The bore stroke of the pistons hasn't changed. We are still drawing in the same volume of air. However, there's less mass, so there's less oxygen to mix with the fuel - there's less to burn. So it shouldn't come as a surprise that a normally aspirated engine is only going to produce about 50 percent of its maximum rated power at 18,000 feet. So we need some method to pump more air into the induction, to increase that air going into the induction at increased altitudes. And turbocharging provides that additional mass of air required to boost an engine's power output at these varying altitudes. AMT

Sea Level: Units of Pressure
Inches of Mercury = (in. Hg.)
Atmospheres = (atm)
Kilopascal = (kpa)
Millibars = (mb)

Pressure equivalents to: 1.0 atm = 29.9 in. Hg. = 760 mm Hg. = 101.3 kPa = 1013.25 mb

Atmospheric Pressure = 14.7 psi & 13 cubic feet of air = 1 pound
Power Loss due to Altitude

Air Density decreases at a rate of 2.9% - 3.0% for each 1000 ft. of elevation above Sea Level. See Standard Atmosphere below for background information.

Naturally Aspirated: Atmospheric Pressure 14.5 psi (It's hard to ride at sea level 14.7 psi)
Atmospheric Pressure @ 9000 feet = 10.5 psi
Pressure Loss = (14.5 - 10.5) = 4.0 (4.0/14.5) = 27.58 % @ 9,000 feet
Does a Turbo lose power with altitude? Yes!

Atmospheric Pressure = 14.5 psi, Boost = 10 psi, Total Pressure = 24.5
Atmospheric Pressure @ 9000 feet = 10.5 psi + Boost of 10 psi = Total 20.5 psi
Approximate Pressure Loss = (24.5 - 20.5) = 4.0 (4.0/24.5) = 16.32 % @ 9,000 feet

The power loss due to altitude is much less with the Turbo. The critical difference is that you can flip the switch on the Turbo to 15 lbs boost and get your sea level HP!!

Turbo considerations: As altitude is increased the turbo fan must increase rpm to maintain a constant boost pressure. With large displacement engines (read 1000cc 4-strokes) the turbo fan may have to spin faster than is efficient. The result is slower acceleration. The cure is a larger turbo or lower elevation.

---------- Post added at 02:56 AM ---------- Previous post was at 02:50 AM ----------

...and here's the proof:

https://www.youtube.com/watch?v=FzzcSQyfTa4

 

[ColoradoBoss]

I did research while waiting for your reply and it sounds to me like the loss differences between the two are negligible. I mean everyone seems to agree that an N/A motor loses 3% per 1000 foot, yet no one agrees on what the loss percent would be for F/I. Like one statement made on another forum, at higher altitude you run less boost. For instance my WRX ran 1.2 psi difference between here and Burlington. Car pulled way harder on i-70 than it did on i-25. So Id argue that the loss is real and I'd say its closer to a 3% loss than what others like to admit. also the video you posted is apples and oranges, all it proves is that the Gen 2 can run circles around the Gen 1. Do the same race at sea level and the results would be the same, proving nothing about power loss at altitude.

 

[lnferno]

I did research while waiting for your reply and it sounds to me like the loss differences between the two are negligible. I mean everyone seems to agree that an N/A motor loses 3% per 1000 foot, yet no one agrees on what the loss percent would be for F/I. Like one statement made on another forum, at higher altitude you run less boost. For instance my WRX ran 1.2 psi difference between here and Burlington. Car pulled way harder on i-70 than it did on i-25. So Id argue that the loss is real and I'd say its closer to a 3% loss than what others like to admit. also the video you posted is apples and oranges, all it proves is that the Gen 2 can run circles around the Gen 1. Do the same race at sea level and the results would be the same, proving nothing about power loss at altitude.

I'd recommend that you watch some races at Bandimere and pay close attention to the naturally aspirated vehicles. Lookup what they run at seal level and then watch what they run up here. Then do the same with the turbo'd vehicles.

I've been 1/4 mile racing since the 80s. Both at sea level and up here at altitude. I'm acutely aware of the effects of altitude on turbo'd, supercharged, and naturally aspirated vehicles. Believe what you want to believe. I've seen it to be proven time and time again. It's science. There's no subjectiveness to it.

 

[jaz13]

Up the mountain to woodland? I'm in woodland. Also just to keep on topic. Forced Induction engines still lose power the same as an N/A engine.

Depends on how the turbo is designed. Airplanes use turbo-normalization, not to add HP, but to maintain seal level HP at altitude.

Ford could easily have the turbo compensate for higher altitudes. The biggest problem becomes cooling at altitude because of the thinner air.

Does Ford incrementally add more boost at altitude? I have no idea, but it would make sense to at least partially offset altitude losses, if not by design, it happens naturally as the engine calls for more boost.

And it seems to work in practice. Driving at 9k', with a fully loaded truck going up a 10% grade, if I keep it floored, I will easily hit the 105mph governor. Not sure a larger N/A truck could do the same.

 

[jabroni619]

I routinely take the raptor to an observatory not far from home which sits at 6100' ASL. When the turbo's are spooled up I cannot really tell a difference in power.

However, cruising around on the freeway when your engine is loping around at 1500 rpms or so there is certainly a difference. Throttle response is slower and it takes a bit longer for the boost to kick in.

That's where the 10 speed is nice to have. Just lock out gears 9 and 10 which keeps the RPMs high enough to let the turbos spool up quickly even at altitude.