you aren't comparing apple to apples, why would the rpm change by adding a turbo?
All things the same, you say it takes less pedal to get the vehicle moving, I agree, but it also takes more air and fuel to be efficient. So you can leave the red light next to and identical truck and use 25% tp and the turbo truck will get there faster, but the N/a truck will take longer to get there, right? So whats the logic on this?...........(period bullshit)

I'm not trying to start a argument with you but the .... is a pause sorta like a rhetorical question. Sorry to have grammatically pissed in your cheerios.

 

Exactly.

Using that same scenario two identical trucks are at the light. They both want to get to 45 MPH(speed limit) so when the light turns green they both hit the gas peddle to 35%. The truck with the turbo gets to 45 in 5 seconds then lets off the gas enough to maintain that speed. The other guy has to stay in it an extra 2 seconds to reach the same speed. The turbo truck would have used more gas in the 5 seconds than the non-turbo truck but the later has to stay on it for 2 more seconds. So the non-turbo truck has to have the pedal to 35% for 7 seconds vs 5 for the turbo truck. Somehow, the turbo truck manages to save some fuel because of that.

Also, if the two trucks are on the highway and want to overtake another car or are going up a hill and want to maintain their current speed or both they would have to give it more gas. At one point the non-turbo truck would give it sufficient gas to cause the truck to kick down to a lower gear where the turbo truck would stay in gear and still be able to pass or maintain the speed.

On the Black Hemi whenever I would go up a hill I would get sucked into boost(3-5 psi) really fast because of the load. This was not good because there was no tuning originally so you would have boost at 14.7 A/F. The only time the A/F would go down was at WOT.

Those are two possible reasons why you might get better mpg but I can't say for sure as I have never personally tested to confirm.

 

So the only place a turbo adds power is in Boost?

 

Maybe we have an engineer here that can give us a little education on what factors contribute to engine efficiency. Just thinking logically here, off the top of my head, induction, intake, heads, combustion chamber design, compression, spark quality, and exhaust efficiency all seem to play a role. Certainly having a turbo effects the induction of the motor in boost, but also out of boost as well since the air still has to go through the compressor to get to the intake.

 

I would guess Kyle could lay some knowledge on us, something else is even "outta boost" you still approach the MAP that you make NA, way earlier

 

Yea turbo will make more power all around but takes more fuel to do so. I'm not a engineer just a user of the turbo, so I'm offering advice!

 

there ya go.....

 

If you wanted fuel economy you should have bought a import sedan

 

almost right.. i was stating that 5inhg meant the turbo was doing something. just trying to make the point that it doesnt have to read boost to be an impovement over an n/a setup.

forget the tp%, figure it like this, just an example here to so please dont flame me. its hard because of so many factors.

a motor making 200ft torque at 3500rpm will use more fuel than a motor making 200ftlbs tq at 2500rpm if the rpm remains constant.

by packing the cylinder more effciently each time the engine can make more power/tq per revolution. the turbo increases the effciency.

now you can drive with a light foot and then go mash the gas make full boost and go to redline and burn twice the fuel you would without the turbo. this tends to happen more because you put the turbo on for a reason, to accelerate faster which does use more fuel.

also.. if you put a turbo that is laggy, you will lose that low end torque gain and most likely will lose mileage.

 

got one...
Lexus GS400