2021 Raptor Is a Total BUST!!

[Raptor R]

Yeah, but. Turbos cause higher back pressure in the exhaust because you route the gas through the turbines. With a SC, you just use headers. Turbos are still way more efficient.

Turbo > Supercharger


Not even close!

 

[Raptor R]

i dont think its lazy, its just too modern. there is too much blue and it reminds me of the blue interior on the navigator. the ram has more contrast going from black to red as opposed to going from mostly blue to dark gray. the recaro interior on the gen 2 has better contract but it could have been more.

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I have the Recardo package in my Raptor. I really like it. They call it the “Blue Accent Package” in Canada. It is a $3-4K option. The Recardo seats are top tier.

I believe that the GEN 3 Raptor is very modern and it is throwing some people off. If you want to compare to the TRX, the TRX is very basic. Still has the old style dash.


Personally, I really like the Gen 3. I think Ford did an awesome job on the truck.

 

[codeman]

That all makes sense to me, as turbos are essentially "free" in terms of efficiency gains, but they aren't and that equation of course is exactly as you mentioned very basic to prove a point. However, it doesn't take into account the difference in gains from small displacement 4 cylinder engines, to 6, to 8 etc. and on top of that there are many other factors like overall engine efficiency to begin with before the turbos hit the equation. I meant "on the whole" just because you slap a turbo on an engine doesn't automatically make it more efficient overall and especially when you take into account the vehicle the engine is driving.

I'm not alone in noticing that strictly looking at theoretical numbers a turbo setup will always seem more efficient. There are other losses however in base power, when you start adding on a turbo like having to run the fuel mixture overly rich than ideal, and because of the lag at times, drivers will cram the throttle harder than you might need to with a NA engine to do something like you might see driving around town, or even cruising on the highway coming up to a slight incline or gusty road with extra drag. The momentum and inherent torque of a V8 like in the 5.0 vs 3.5L ecoboost will keep the engine moving along with less pedal movement. Turbos also bring in a much tighter requirement for proper engine management etc.

It's complicated, but the basic on paper numbers like you took the time to point out there, I'm not at all in disagreement with. I agree fully, and is why automakers are jumping to cover their asses with a bunch smaller turbo'd engines to meet fuel economy numbers.

 

[Dirtypope]

i dont think its lazy, its just too modern. there is too much blue and it reminds me of the blue interior on the navigator. the ram has more contrast going from black to red as opposed to going from mostly blue to dark gray. the recaro interior on the gen 2 has better contract but it could have been more.

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This are pictures from Gen 2. My truck has same interior. I was expecting more for Gen 3

 

[rtmozingo]

That all makes sense to me, as turbos are essentially "free" in terms of efficiency gains, but they aren't and that equation of course is exactly as you mentioned very basic to prove a point. However, it doesn't take into account the difference in gains from small displacement 4 cylinder engines, to 6, to 8 etc. and on top of that there are many other factors like overall engine efficiency to begin with before the turbos hit the equation. I meant "on the whole" just because you slap a turbo on an engine doesn't automatically make it more efficient overall and especially when you take into account the vehicle the engine is driving.

I'm not alone in noticing that strictly looking at theoretical numbers a turbo setup will always seem more efficient. There are other losses however in base power, when you start adding on a turbo like having to run the fuel mixture overly rich than ideal, and because of the lag at times, drivers will cram the throttle harder than you might need to with a NA engine to do something like you might see driving around town, or even cruising on the highway coming up to a slight incline or gusty road with extra drag. The momentum and inherent torque of a V8 like in the 5.0 vs 3.5L ecoboost will keep the engine moving along with less pedal movement. Turbos also bring in a much tighter requirement for proper engine management etc.

It's complicated, but the basic on paper numbers like you took the time to point out there, I'm not at all in disagreement with. I agree fully, and is why automakers are jumping to cover their asses with a bunch smaller turbo'd engines to meet fuel economy numbers.

A turbo engine will always be more efficient.
You are using waste energy otherwise lost - no other engine system does that. By definition - as I've shown - this makes the engine more efficient. When you reduce lost energy in the system the efficiency of said system increases.

Considering your point a bit more, it depends on the system boundaries. A turbo will always make the engine more efficient, but you could set your system boundaries such that a smaller, turboed engine would be a less OVERALL efficient choice than an NA V8. Such systems and situations would be very rare, but I suppose they could exist.

Did you subtract the 25hp twice? Shouldn't the equation be 575=50+50-25?

Yes, good catch. It didn't look that way following the equation but that's because I set it up wrong.

 

[Jakenbake]

Ugh, you guys are going to make me do some mechanical engineering - and thermo/heat transfer at that. I'm a nuclear engineer by degree and trade, so I may make some small mistakes. Feel free to correct me or refer to better material - but overall, the information here should be correct.

Roughly, our closed system looks like this:

W= Qin - Qout
where
W = work done by engine
Qin = energy put into the system (how much energy is produced directly by combustion)
Qout = energy lost from all sources

I will rewrite the equation as Qtot = W + Qlost for now, as I think it is easier to visualize. You can think of Qtot as the total energy our engine produces - most will power your wheels, but some is lost in the form of hot exhaust (as well as other places)

For the purposes of our scenario, we will assume the engine and system as a whole is EXACTLY the same, excepting that we will add the turbos or supercharger as we see fit.


Let's say our engine produces 600hp. Combustion isn't perfect however and we can't transfer 100% of the energy anyway. Let's say we lose 100hp, making our net result is 500hp. Our equation is then:

Qtot = W + Qlost
600hp = 500hp + 100hp

Of the lost 100hp, where did it go? For simplicity, we'll assume 50hp is lost to driving other systems off the drivebelt, and the other 50hp goes out the exhaust. Our equations:

Qlost = Qexhaust + Qdrivebelt
Qtot = W + Qexhaust + Qdrivebelt
600hp = 500hp + 50hp + 50p

Our efficiency - defined as W/Qtot, is equal to 500/600 = 83.3% (too high to be realistic, but whatever).

Let's add a supercharger - it adds 150 hp to our engine, but is driven off another belt off the engine - a parasitic loss:
Qlost = Qexhaust + Qdrivebelt + Qsupercharger
Qtot = W + Qexhaust + Qdrivebelt + Qsupercharger

I seem to recall a draw of 75hp is a decent number for superchargers. So:

Qtot = W + Qexhaust + Qdriv
750 = W + 50 + 50 + 75

W = 575hp. We only gained 75hp of work out of the engine. Our efficiency is now 575/750 = 76.6%.

Alright, let's go back to turbos. Turbos use exhaust gas to produce boost. This means some of Qexhaust is actually recovered and added back to the engine as work - not all of it, but some. For our equation we actually subtract it, making Qlost look different:

Qlost = Qexhaust - Qturbo + Qdrivebelt

Let's assume we get 50% efficiency out of the turbo - half is still lost to exhaust, but half works as boost (25 hp each). It gets a lot more complex here in reality, but we'll keep it simple.

Qtot = W + Qlost
Qtot = W + Qexhaust + Qdrivebelt - Qturbo
550 = 500 + 25 + 50 - 25

Our efficiency is now 500/550 = 91%!!!


To recap, our NA engine was 83%, our supercharged engine was 76.6%, and our turboed engine was 91%. There are much better in depth articles on the subject, but hopefully you see why we say a turbo engine is the most efficient and supercharger is the least efficient. It is also why turbos are now preferred by all manufacturers seeking to improve fuel economy and why superchargers are only used in select performance applications, where the linear boost is helpful. Or, in the case of SRT, that's all they are capable of doing.

It is good to dust off the books you haven’t picked up in a while. I had a thermo class about 8 years ago so this conversation is bringing back some memories. I actually am not sure where my book is to dust off lol.


In regards to the “turbo” equation should we not add a term for losses associated with added back pressure? Yes I agree it is capturing otherwise lost energy but it has to be at a cost.

I know tone and emphasis is hard to read over text, I just like a good debate. I believe that knowing why is just as important as knowing how. Knowing that “blank” equation solves the problem is good, but knowing why it does is very important as well.

For the record, I like turbos. I also wouldn’t turn down a whipple if someone gave it to me....

 

[rtmozingo]

It is good to dust off the books you haven’t picked up in a while. I had a thermo class about 8 years ago so this conversation is bringing back some memories. I actually am not sure where my book is to dust off lol.


In regards to the “turbo” equation should we not add a term for losses associated with added back pressure? Yes I agree it is capturing otherwise lost energy but it has to be at a cost.

I know tone and emphasis is hard to read over text, I just like a good debate. I believe that knowing why is just as important as knowing how. Knowing that “blank” equation solves the problem is good, but knowing why it does is very important as well.

For the record, I like turbos. I also wouldn’t turn down a whipple if someone gave it to me....

I was trying to keep it simple, but there are many losses associated with the turbo system. However, you are still recuperating the exhaust losses, so even if you lose A LOT in the turbo, you still get an net gain.

Ultimately Qturbo = W + Qlostinturbosystem (Where Qlost would be everything from heat exchanger irreversible losses to back pressure).

If I remember correctly, this article has just about everything you'd ever want to read on heat transfer modeling of turbochargers.

 

[Raptor R]

This are pictures from Gen 2. My truck has same interior. I was expecting more for Gen 3

So, you don’t like the blue? What would you change then for the Gen 3 interior. Red accents?

 

[Dirtypope]

So, you don’t like the blue? What would you change then for the Gen 3 interior. Red accents?

I would add more emblems and make unique and a maybe serial number or badge in the middle making more personal. I hate the red and blue and orange it’s actually nice touch but they should did something with more emblems like they did to Bronco. Also the pedals I would make the more attractive not some regular pedals like f-150

 

[nmp1]

the quality looks fine, there is just way too much blue. blue alcantara, blue leather, blue plastic, then they add orange stitching. raptor buyers don't want modern to this level. stick with colors that always work together.