Turbo gas mileage...
01-12-2009, 09:23 AM
#91
01-12-2009, 09:26 AM
#92
01-12-2009, 10:15 AM
#94
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It might take less exhaust gas to spin the turbine at to a certain rpm, but that doesn't mean it's less restrictive. There are a ton of factors that have to be considered before saying a smaller turbo is less/more restrictive. A/R ratio, flange size, turbing blade angle, size/design, exducer bore etc. I think what you're saying is that at cruise a smaller turbo has the chance of being less restrictive, whilst the compressor side is feeding the engine. But a larger one would require more exhuast gas to move it, but it might be able to get the job done at a lower turbine speed.
The downpipe should be considered here as well since most factory offerings leave a lot to be desired.
The downpipe should be considered here as well since most factory offerings leave a lot to be desired.
01-13-2009, 12:37 AM
#96
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01-13-2009, 10:12 AM
#97
All I can add to this back and forth fest here is that my truck got about 17-18mpg before my turbo install with a stock tune. After the install with a mail order tune with a mix of driving the same exact route numerous times checked i gained about 1-2mpg in mileage. Now much really but my driving is pretty consistent. It seemed that if i was just a little bit more into the gas that i got better mileage. Not like 5psi but just on the positive side of vacuum.
I also tried adding 2oz. per gallon of acetone to my fuel and gained another 2mpg!! It worked. I did it four times in a row under just about the same conditions in close to the same weather.
Not a scientific test but real world.
I also tried adding 2oz. per gallon of acetone to my fuel and gained another 2mpg!! It worked. I did it four times in a row under just about the same conditions in close to the same weather.
Not a scientific test but real world.
01-14-2009, 04:02 PM
#98
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01-14-2009, 06:04 PM
#99
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I find that description of the gain hard to believe. I am sure you know that the pump wheel requires speed in order to move air out past the discharge area. Under normal driving conditions (no load) that turbo is not doing ANYTHING other than sitting there. In order for you to make less Vacuum you would need to be in boost....therefore making your statements of not being in boost during normal driving untrue. I would rather you make the statement "gas mileage was greatly improved due to the tuning, and power has increased from the turbo". This would have been a true statement.
01-14-2009, 11:27 PM
#100
Here is some food for thought.
Top Gear a tv show on bbc, did a test. They raced a prius aganst an bmw M3.
Athough what the did different was, the Prius led as fast as it could and the M3 just had to keep up.
The prius got somewhere around 11 mpg racing around the track and the M3 got 17mpg.
My idea, if this hasn't been covered already, is the truck when the turbo was added produced the same power at cruise with less effort.
Just like the race between the Prius and the M3.
Top Gear a tv show on bbc, did a test. They raced a prius aganst an bmw M3.
Athough what the did different was, the Prius led as fast as it could and the M3 just had to keep up.
The prius got somewhere around 11 mpg racing around the track and the M3 got 17mpg.
My idea, if this hasn't been covered already, is the truck when the turbo was added produced the same power at cruise with less effort.
Just like the race between the Prius and the M3.