right, it adds EFFICIENCY (turbo only)

Its hard to imagine that even with the valve totally open, and no energy being spent on creating boost, that your turbo isn't also restrictive. I see no straight sections as wide as the exhaust pipe.

With the turbo creating even a little boost (or just enough), it is providing enough extra efficiency to negate its comprimising effects on the engine. (-a belief)

I do not mean to be antagonizing and I apologize if you have already gone the hoops of trial and error finding the exact spot where efficiency and fuel consumption meet. Would this would mean that the exhaust being passed through the turbo is small enough to get by w/o backpressure, and that the corresponding fuel usage is just enough to keep you coasting?

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Incorrect. A turbo only adds power.

damn.

Any suggestions for where I can read up on turbos?

--on a NIN kick, huh?--

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http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech101.html

been there

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Turbo adds air to be burnt, thus power. it takes away less power at the crankshaft than a supercharger (supposibly a supercharger leeches 1/3 the power at the crankshaft).

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1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

can i see some picture please, where to find trap cat place and what its lookof this. and one thing more how to remove it. hope that you could me out. thanks a lot sir

http://www.peachparts.com/Wikka/OM617CalToFed

The way I like to explain any forced induction is based on the fact that an engine is an air pump. Plain and simple, an engine will move a certain volume of air from sucking in the intake and pumping it out the exhaust for a given rotation. The typical 4 cycle will require 2 revolutions to use all of the cylinders making the number equal to the displacement capacity of the engine. When we supercharge or turbocharge we actually make the engine appear to have greater displacement. This larger capacity means the engine pumps more air and thus can burn more fuel. This artificial capacity increase is based entirely on the amount of boost pressure present at the intake manifold. A couple of neat things are made capable from this. One is that we can take a small, lightweight engine which can rev fast due to low reciprocating mass and increase the torque and HP ouput significantly. This also leads to a general fuel saving because we are using a small displacement engine all the time, and depending on the boost to increase the horspower when it's needed for short period of time. Understand that in a gasoline engine, we use the throttle to restrict the intake and do the exact opposite, making the cylinders less full of air and thus less fuel for a reduction in displacement per revolution.

Some of the other comments are true: Any artificial induction has losses all the time and will increase fuel consumption across the board on a given engine (even when not producing boost). The only systems that severly limit this loss are like the Mercedes SLK supercharger with a clutch and a series of valves/airchambers to bypass the entire system when in a non-boost condition. Even then, friction and aerodynamic losses have some slight increase in fuel consumption (measureable but not significant).

simply put:

Increasing the power to weight ratio improves vehicle efficiency.

thank you for concluding this thread, Barrychuck.

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a turbo only does this during acceleration. at constant speed it will always have pumping and heat losses.

Okay, guys. A turbo or supercharger increases the air intake pressure, increasing the air density, which means more oxygen molecules pumped into the cylinder to combine with fuel in the combustion process. A charge air cooler, commonly called an intercooler in automotive circles, increases the density of the air entering the cylinder by lowering its temperature (the old pressure:volume:temperature relationship), also increasing the number of oxygen molecules entering the cylinder. The increased oxygen present means more fuel can be added. Burning (completely) more fuel per stroke results in more power per stroke, and increases the overall power and torque output of the engine. Because more power is produced per stroke, fewer strokes per minute (or rpm) are required for the same power output...resulting in increased fuel efficiency, whether accelerating or operating at a constant speed, for the same power produced. This is why most marine diesel engines (which frequently operate at relatively constant speed for extended periods) have turbos on them, as do most diesel generators used on ships...when your fuel bill is several million dollars per year, per ship, you want to maximize your efficiency.

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