Lets talk "Power Adders"

[wmjinman]

Originally Posted by SilveradoMike

Im still having trouble understanding how improving power (mostly low end torque) wouldn't translate to an increase in mpg. Letting the engine make the same amount of power eaiser or at a lower rpm seems to make sense in my head. My thinking is this. If you have two identical trucks with idenical loads and total weight. But one has 500hp/tq and the other has 250hp/tq. Wouldnt the one with more power be able to do the job eaiser? There for reducing load on the engine and thus decreasing throttle input/fuel usage? Both being driven same route/speed ect.

Yeah, I think "easier on the engine/truck" doesn't necessarily mean "using less fuel". A big, burly football player could undoubtedly carry an old lady's groceries out to her car "easier" than she could too, but I'll bet he eats more!!!!

It was touched on here already, but the best BSFC is usually at higher engine loading. If you have a monster engine, the only time it'll be at that higher loading is when it's doing some SERIOUS work, like hauling a huge load, driving really fast, accelerating really hard, etc. (which are all bad fuel economy situations)

Therefore, increasing the power of the engine, is probably working against fuel economy. Now - - - I don't know, it might be working to help engine life - - - ?????

[UFO]

Originally Posted by mechman600

You are not suggesting that a Cummins Big Cam was a clean engine, are you?

I shudder to think of the amount of hydrocarbons emitted every single time one of those started up cold. So much smoke that we had the fire department show up at work one time. The later STC versions weren't as bad, but still....

Visible smoke always seems to imply dirty. I won't argue some of these engines burning diesel have bad emissions, but at least they do not put out the VOCs and carbon monoxide that gasoline engines are good at. Non-visible pollutants are much more dangerous than the filth you see from diesels.

[cRiPpLe_rOoStEr]

Originally Posted by mechman600

You are not suggesting that a Cummins Big Cam was a clean engine, are you?

I shudder to think of the amount of hydrocarbons emitted every single time one of those started up cold. So much smoke that we had the fire department show up at work one time. The later STC versions weren't as bad, but still....

The low compression, altough makes it easier to start it up, takes a longer time to get the operational temperatures and stabilizing the idling...

[mechman600]

Originally Posted by cRiPpLe_rOoStEr

The low compression, altough makes it easier to start it up, takes a longer time to get the operational temperatures and stabilizing the idling...

A Cummins Big Cam wouldn't start if you walked by it with an ice cream cone.

[cRiPpLe_rOoStEr]

Originally Posted by mechman600

A Cummins Big Cam wouldn't start if you walked by it with an ice cream cone.

I should've said it's easier to break the inertia

But as I pointed out, getting the operational temperatures takes soooooo long

[SilveradoMike]

Yeah I wish diesel swaps were an option here. I love the older 80's fords with the International IDI Diesels. Super simple, decent power, and on my 86 dually 4x4 it got ~20mpg (non turboed)

[pete c]

You can tell an ecomodder forum newbie when they bring up the free breathing intake argument regarding gas engines.

It seems to make perfect sense, until you look at minor details concerning how a gas engine is controlled. You mod it by restricting the intake!!!!!!

What gets me is that some of these newbies fail to see the light, now matter how brightly we enlightened folk shine it. It shows the power of years and years of K&N advertising/brainwashing.

[oil pan 4]

Originally Posted by pete c

You can tell an ecomodder forum newbie when they bring up the free breathing intake argument regarding gas engines.

Thats why I like diesels. The more air you feed them the better everything works.

[tayjo22]

Originally Posted by oil pan 4

Thats why I like diesels. The more air you feed them the better everything works.

So I don't know much about diesels and I am looking into getting one. Are you saying that imrpoving air flow with this type of engine is actually recommended for better mpg? Please shine brightly on this one enlightened folks you will be helping a future ecomodder studying the ways of passing gas and adjusting the nut behind the wheel.

[Viturro]

Exactly
Diesel-
More air, same fuel = more power
More air, more fuel = much more power
More air, less fuel = same power, less consumption
I think so... :P