A New Lease On Internal Combustion

Somnus suggests we check out the latest issue of MIT's Technology Review, where researchers describe how they can dramatically boost engine output and efficiency by preventing pre-ignition, or "knock." How they do it: "Both turbocharging and direct injection are preexisting technologies, and neither looks particularly impressive... by combining them, and augmenting them with a novel way to use a small amount of ethanol, Cohn and his colleagues have created a design that they believe could triple the power of a test engine."

Comments

Rudolph Diesel

[LiENUS]

Congratulations You've discovered the same thing as Rudolph Diesel except that you don't quite have it right. You don't need to use ethanol or port injection ditch both of those and use good ol fashioned vegetable oil. 0 preignition and you can turn the boost way up on a tiny engine.

Re:Old

[drinkypoo]

This is exactly like water-injection and it's why we don't see water-injection in vehicles. No one wants to have a separate tank that we need to remember to fill-up, and the 10% increase provided by water just isn't enough. This is the same story except it's ethanol, not as easy to find as water, and it's 25% better mpg instead of 10%.

But the story is different because the system will know what to do when it runs out of ethanol, which is to say retard timing and reduce mileage and power output until you add more ethanol. Water injection is aftermarket and usually not compensated for automatically.

The mileage improvement is pretty compelling and I think we'll see it implemented if fuel prices rise much more.

Re:Check out the 07 MINI - it has this stuff alrea

[GameMaster]

You either need to read the article or, if you have, brush up on your reading comprehension skills. The technique used in the article is supposed to allow them to push the turbo pressure much higher than any modern car can handle, even when using high octane fuel. They're talking about using a separate direct injection system to pump a small amount of pure ethanol into the cylinder out of phase with the gasoline. It would cool the cylinder enough to stop knock when the gas is injected at extreme pressures. Supposedly, you would have to replace the ethanol about as often as you have to replace the oil (every few months).

Next time, please try reading the article instead of seeing "ethanol" and "turbocharger" in the summary and shooting your mouth off.

-GameMaster

Re:brief review of article

[Anonymous Coward]

Who gives two shits about making petrol engines 25% more efficient when Diesels are already 50% better in practical applications.

Once again, this just shows that what Americans don't know about car technology could just about be crammed into the Grand Canyon.

Volkswagen already have quite a few turbocharged FSI petrol and Diesel engines - take a look at how efficient they are before swallowing this MIT bullshit.

Re:Old

[RingDev]

"...limiting their power"

Harsh. Apparently someone hasn't been keeping up on Diesel Technology lately. You know it was an Audi Diesel that one the last LeMans right?

I dirve a little VW Golf TDI. 115hp is nothing special, but 175 lbs/ft of torque is enough to get the car moving in a hurry. The car is almost as quick stock as my '88 Fiero with a 3.4l V6 (about 180 hp and 175lbs/ft).

When you have an engine that can (lightly/medium modded) put out 250 lbs/ft or torque from 1800rpm to 3500rpm, the concern is less about RPM and more about Gearing and shifting. Have you seen the new VW/Audi dual clutch manual automatic trannys? Their 6 speed DSG auto transmissions can upshift in 8ms. With that wide of gear range, and that fast of shifting, having a somewhat* limited rpm band is not an issue.

*I say somewhat because the vast, vast majority of drivers will never spin their engine over 3500 rpm. Hondas, Subarus, what have you, they are all designed (stock) as commuter vehicles. And if you have to turn 7k rpms to get your car off the line, it's not going to hold up to daily driving.

-Rick