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Old 06-13-2009, 05:56 PM   #42 (permalink)
roflwaffle
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Join Date: Dec 2007
Location: Southern California
Posts: 1,490

Camryaro - '92 Toyota Camry LE V6
90 day: 31.12 mpg (US)

Red - '00 Honda Insight

Prius - '05 Toyota Prius

3 - '18 Tesla Model 3
90 day: 152.47 mpg (US)
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Quote:
Originally Posted by Big Dave View Post
A LS2 makes 405 HP. How many minutes of full power do you suppose that a LS2 actually see in its service life You can get some serious tickets by driving 175 MPH.
Generally speaking, most vettes that aren't bought for the "image" get raced at tracks and such. Heck, someone could gut a Prius and turn it into a race car, but it'd be a bit odd and more expensive than just getting something designed to race, just like swapping a diesel into a vette is a very expensive way to get a ho-hum economy car.
Quote:
Originally Posted by Big Dave View Post
The diesel is what pushes a 'Vette over 40 MPG. You could put an itty-bitty gas engine in it but I don't think 40 MPG is possible without competition-grade hypermiling. The diesel, with its higher efficiency does it easily.
Proper gearing compared to BSFC is what gets a car like a vette over 40mpg (energy adjusted), regardless of engine type. A chebby gen iv engine at ~250g/kWh will hit ~40mpg@65mph, just like a 4BT at 225g/kWh will hit ~45mpg, and they'll both be at a shade over 30% BTE (diesel has more energy per gallon than gasoline).
Quote:
Originally Posted by Big Dave View Post
The propane/nitrous is there for bursts of acceleration. I specify nitrous to avoid having to put a bigger turbo on the engine (and accept more turbo lag) for maybe fifteen minutes of raw power a year. Its simply "turbo logic." With a turbo, a small engine can have a "Jeckyll and Hyde" personality. Economical most of the time, but powerful when needed. How many turbo cars are at full boost much of the time? They'd grenade themselves.
If someone only needs 15 minutes of raw power every year then why even both w/ a vette and a 4BT/LSx/whatever? Just go w/o those 15 minutes of power and grab a beater IDI VW. 40+mpg@65mph and it'll only cost a few hundred bucks.
Quote:
Originally Posted by Big Dave View Post
The little Cummins is straight mechanical and I don't have to mess with electronic controls.
I never understood the preoccupation w/ mechanical versus electrical. It's all basic engineering/physics and it's all gud. All things being equal, electric engine/emissions control is just as reliable as mechanical, although I imagine that it could get pretty hairy given some of the QC seen w/ domestic manufacturers in the past, but that's QC, not some intrinsic mechanical versus electrical problem.
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