I've heard that turbocharging can actually increase fuel efficiency. Is this possible? Since you have to add more fuel to all that extra air I don't see how this could be true.

 

You increase volumetric efficiency. You will use more fuel to make more power, but you will make more power with less fuel than increasing the horsepower with other methods.

 

Yeah, usually when I hear a statement like that, they're talking about installing a smaller-displacement turbo engine with the same power as the NA engine.

 

yes in the way that a stock turbocharged vehicle will have a better fuel economy than a non-turbocharged vehicle with the same power...

then again... who puts a turbo on a honda to have better fuel economy?!

 

Engine efficiency is usually measured in BSFC: Brake Specific Fuel Consumption. It's measured in lbs. of fuel/hp/hr. An inefficient engine would be roughly .50 lbs/hr. A more efficient value might be, oh say .35 lbs/hr.

Of course, VE is superior with artificially aspirated motors, but a Roots blower putting out 10 psi would have a poorer BSFC than a turbo putting out the same boost.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ek9t &raquo;</TD></TR><TR><TD CLASS="quote">then again... who puts a turbo on a honda to have better fuel economy?!</TD></TR></TABLE>

I do. Well it was one of the reasons anyway. The other reason is that I live on this big *** hill.

 

Actually, its said that turbo cars have a higher bsfc then supercharged cars. Due to heat related pumping loses and exhaust restrictions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fredtoast &raquo;</TD></TR><TR><TD CLASS="quote">I've heard that turbocharging can actually increase fuel efficiency. Is this possible? Since you have to add more fuel to all that extra air I don't see how this could be true.</TD></TR></TABLE>

It might theoretically be more efficient because you're extracting otherwise wasted energy from the exhaust to help pump air into the engine. The fact that you're using more fuel does not mean you're less efficient....efficiency is how much power you're getting out of the fuel you're burining. A power plant burning 200 tons of coal an hour is probably more efficient than a civic at cruising speed.

So basically, it takes up a certain amount of power to pump air into the engine. A turbocharged engine gets this power from the otherwise wasted exhaust. I'm just not sure if this actually results in more efficiency in practice.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shaundrake &raquo;</TD></TR><TR><TD CLASS="quote">

I do. Well it was one of the reasons anyway. The other reason is that I live on this big *** hill.</TD></TR></TABLE>

i don't believe that for a second

me turbo me use lots of gas but efficiently smoke vets

 

Tell us about your tuning, engine management, and amount of boost. You probably have a lot of boost, a chipped ECU, and bumped fuel pressure, right? Maybe one of those piggyback ECUs like Hondata.