There’s a lot of development that’s been going into turbochargers these past years, driven by the feds necessitating them to get acceptable performance while still meeting constantly more stringent fed requirements. Things like “turbo lag” will soon be a thing of the past.
I still prefer natural aspiration, but in truth I’ll bet that in the coming years ICE engines will slowly become passé anyway. Twenty years from now I suspect gas engines will comprise a very small portion of the new cars offered. Most everything will be EVs.
Well, you know that another way to give a small engine extra passing power is to couple it with an electric motor/generator like the Prius and Honda Insight.
If I was to take something like a '91 Geo Metro and turbocharge it, I doubt that I would improve its mpg, in fact needing to lower the compression ratio in order to run boosted without detonating would likely lower the mpg. Also, in order to achieve its stock mpg, I would have to drive in a way that rendered the turbo passive anyway.
But I would still get better mpg than a bigger engine that matched its passing power.
On diesels, it’s a whole different story. The air is never throttled and so any turbo boost is simply energy returned to the engine, turning the intake stroke into a second power stroke. That’s why turbos have become almost universal in diesel engines, even stationary power plants. You could consider a turbo diesel a combined cycle engine.
@mountainbike. I sincerely hope you are right. I went through an old article in my car library. It was from Mechanical Engineering Magazine and predicted that by the late 70s gas turbines would replace piston engines because of the turbine’s mechanical simplicity. Heat recovery heat exchangers would make them as efficient as piston engines.
Motor Trend also had a number of articles when the Chrysler turbine cars went to a select number of test owner/drivers. They said they would change the magazine’s name to “Turbine Trend” when it all came to pass. I’m still waiting.
Agree there will be an increasing number of electric vehicles, but as long as ENERGY DENSITY (the amount of energy you can pack in a certain space or weight) keeps rearing it ugly head, we will end up with short range commuter vehicles, largely electric and long distance vehicles which will have engines and may be hybrids.
Things like “turbo lag” will soon be a thing of the past.
I have to wonder how old your turbo engines are. From 1989 to 1992 Chrysler offered a VNT (variable nozzle thrust) turbo with virtually no turbo lag. Open the throttle from a stop and the front tires will spin. Customers chose the V-6 over the turbo 4 so the turbo was dropped as an option.
Turbos during the 2000’s behaved as expected, with minimal turbo lag. The problem with the latest generation is no different than with normally aspirated engines, the reluctance to down shift in the interest of fuel economy. When opening the throttle while moving at 30 MPH a little 2 liter engine won’t provide much power at 1500 RPMs, turbo or without. One must manually control the transmission or use the “sport” mode to experience reasonable performance.
Why isn’t turbo on all the time? I thought it increased the oxygenation of the mixture, increasing the efficiency of the burn, an advantage all the time.
Interesting you guys mention the Kawasaki… I had the Suzuki “Water Buffalo” 2 Stroke Triple. Sorta the same thing… Jay Leno did a piece on the Kawasaki’s “Then and Now” or something like that. Since they released the modern Supercharged version of that 70’s bike…
Interesting indeed…Jay mentions how pretty much nothing could touch those 70’s bikes in their day…and how devastatingly fast the modern version is…with almost 300 RWHp. Jay kept having trouble wrestling with his perceptions of what we once thought was the ultimate in speed…and what is considered fast now.
Here is the link to those impressive machines… You should enjoy this…
@RandomTroll
Why isn't turbo on all the time? I thought it increased the oxygenation of the mixture, increasing the efficiency of the burn, an advantage all the time.
It doesn’t work that way in a spark ignition engine. Too much air results in a mixture that is too lean to burn. That’s why these engines throttle both the air and fuel together to keep the air to fuel ratio in the order of 14 pounds of air to one pound of fuel. That ratio can vary slightly, the best power comes from a mixture that’s around 12-12.5 to one, a slight excess of fuel to insure that all the oxygen is consumed. The best economy comes from a mixture around 14.5-15 to one, enough air to ensure that all the fuel is burned.
Too much air and you dilute the mixture with unusable oxygen and that reduces the efficiency of the engine and in taken too far, it results in misfiring.
Another thing we may see in the future is tubo-compounding. Here, instead of the exhaust turbine simply driving the air intake compressor, its power is absorbed by a generator that supplies power to the electric motor end of a hybrid system. In this system, the exhaust turbine is supplying energy even when the engine is producing only the amount of power it could achieve normally aspirated. Also, that generator can become a motor to spin up the turbo at low rpms for better low rpm torque.
Its funny we are mentioning Turbo Compounding… Something that was done during WWII on Aircraft back in the 30’s… It has been done on Diesel engines… The would use a Turbo AND A Supercharger at the same time.
BLE brings up the latest iteration of compounding…using the Turbo to spin a Generator…to store power for an electric motor…to then spin up the turbo during times of low airflow/low or no Boost ability. Mercedes has done this in their F1Technology of today… A great way of utilizing all that movement produced by the Turbo… Of course the Turbo needs to be configured properly to handle these additional loads…along with a longer turbine shaft to drive something else…but it can be done…and is being done.
Interesting times we live in…maybe one day this F1 Tech will trickle down to us lowly Street Autos…Cant wait.
With a electric motor/generator tied into the turbo shaft, the generator can limit boost by absorbing energy and sending it to the hybrid drive motor, instead of using a waste gate to limit boost, and it’s called a “waste gate” for a reason.
Yes indeed… it opens up all sorts of interesting things doesn’t it ? We live in good times right now… We will probably see the Utmost iteration of the ICE in our lifetimes…and that is a real possibility …while it is exciting…it also makes me sad. Can you guys imagine? The last revision of the Internal Combustion Engine? People will refer to this time in the textbooks for years to come…and we will more than likely see it happen.
I dont know how I feel about this… Many people’s entire life has been dedicated to this invention…Careers have been made, Professions, all sorts of things can be tied to the ICE… It will truly be the end of an Era in all connotations of the words.
Yeah, a few years ago, when I mentioned that some aircraft during WW2 had turbo chargers AND superchargers, one of the regulars told me in no uncertain terms that I was wrong, in spite of the fact that I know what I read. Sorry if I can’t remember the name of the book I read all those years ago
And now Honda is talking about it matter of factly, and nobody’s saying he’s mistaken
That whole incident left a bitter taste in my mouth
Telling me I’m wrong when I was the one that read the book, not the other guy
I know Honda’s not the one that told me I was wrong
Sorry if I’m not an engineer or other learned individual who can cite documents, papers, etc. and PROVE the existence of something, or prove something to be true
Sorry if I’m rambling and bringing up old stuff, but there’s some things that just make me upset
and whoever you were . . . and I know you’re one of the active regulars . . . here you go
I think the concept of using a turbine in tandem with a reciprocating engine was already being used back in the days of steam engines. Reportedly, the Titanic used two triple expanding reciprocating steam engines to power the outer propellers and their combined exhaust then fed a low pressure steam turbine that powered the center propeller, before the steam entered the condenser to be turned back into water to be pumped back into the boilers.
Doc, cars with a range well in excess of 200 miles transcend the short range commuter vehicle definition. Elon Musk has made tremendous advancements in EV technology, and I don’t see it stopping here. He’s addressed and is addressing not only the technology, but also the need for recharging stations and the entire sales and delivery model. He’s never run a commercial or an advertisement, and yet he’s had hundreds of thousands of customers put their money down without ever seeing the vehicle. I won’t be here to see it, but I truly believe that future automotive historians will look back on Tesla as being a vehicle that changed the automobile… and maybe the industry.
When I was commuting, I needed a car that would do in excess of 120 miles a day. Some days I’d have to go over 400 miles in a day. Now that I’m retired, last weekend it was 400 miles out and 400 miles back. Next week its 880 miles out and 880 miles back. You could do 200 miles just as well in a golf cart. I’ve gotta have something that can be run continuously for however far I’m going.
Bing, yours is unusually high daily mileage. No vehicle will meet all needs, but the Tesla doesn’t have to in order to satisfy the overwhelming majority of the drivers. Or to change people’s perception of what an EV is and to change the marketplace. Tesla has already accomplished the first goal. We no longer talk about EVs as very short range tiny beanpods unable to get us to work and back without running out of juice. We now discuss Teslas as a competitor to entry level luxury sport coupes, and entirely capable of serving the average person for the entire day before needing to be recharged. He’s now continuing to improve the product and the way it’s marketed and sold.
Comparing it to a golf cart? Oh, come on. That’s just plain ridiculous. Except perhaps in some retirement communities in Florida and Arizona. Teslas are full-fledged family cars. Golf carts aren’t even close.
I agree completely with TSM. The Tesla is a very capable family vehicle. The average national commute is 25 miles. The Tesla can go for almost a week I that charge. And places like Boston have charging stations at almost all the parking garages. Cost has been coming down. Battery technology has improved significantly. I can’t wait to see what it will be like in 10 years.
@mountainbike There are several Teslas in my area and a large shopping mall has a Tesla sales outlet!
However, winter weather severely cuts down on the range, and where we live there are precious few recharging stations out of town. On a weekend we drive 100 miles or so into the mountains. That trip is hard on batteries and I would not dream of taking an electric vehicle. So there will be a market for both types of vehicles, even if Tesla gets the price of batteries down to an affordable level for the average driver.
If I lived in Boston our family would likely end up with a gas car and an electric one.
With respect to climate change, electricity from a coal fires station used in an electric car saves a little in CO2 generated, but not significantly to affect climate change. When we start charging them from solar panels there will be real savings.
@db4690 I must have missed that argument over Turbo Compounding… I never knew it was up for debate…certainly should not have been. Very well known… I remember a few yrs ago working on a Rybovich Yacht…(Basically a Ferrari of the Boat World) and I was marveling at the Compound Turbo/Supercharged 2 Stroke Diesels it had in the Engine Room. It made me think of the WWII Engines of yesteryear that I never had the opportunity to even see let alone work on.
Wonder when this debate had come up… I would have stuck up for ya…
I’m happy in my ignorance that I don’t hardly know what you guys are talking about.
Now 2 stroke diesel? Years ago here, I claimed that there were two stroke diesels and was pretty much told that I was nuts. I don’t know who it was either, but guess I was right after all. Please tell my wife I was right once. Of course I’ve had worse things leveled at me so no big deal.
