Why would the 1.8L Engine only be 100HP

I don't think this would be the case. The current engine is already more powerful than needed for cruising. Adding a turbo would only add additional unneeded power which wouldn't be used while cruising.

To increase cruising efficiency, from the standpoint of modifying the engine, you need a less powerful engine that cruises in its sweet spot to avoid pumping losses. A throttle-less engine would also accomplish this.

Perhaps when you suggest that turbocharging the engine would improve cruising efficiency you were thinking of replacing the engine with a smaller turbocharged engine? That could work.

Tom

 

If you want to modify the HSD, you are probably better to start by hiring a software engineer (and a good one, to reverse engineer the different ECUs), and then a good mechanics.

The HSD is like an iceberg. There is more to it than what you see in the physical world...

 

The one author who has both supercharged and turbocharged his Prius, found he did not increase peak power to the wheels, he increased electrical power to the batteries, instead.

 

That is to be expected. Toyota has made the thing very difficult for mortals to modify. A higher power engine also needs cooperation from the motors and ecu to get the power to the wheels. If someone cracks the code then more heavy duty parts may be needed, but that's the only way I would expect to get better acceleration out of the beast. Bigger wheels could give it higher top speed though.

 

He did however note 2 second quicker 0-60mph time. I'm curently working on a turbo project for my 2010 Prius. More details wil come as the project progresses, hoping to have it up and running by the end of July. I'm not afraid to venture into uncharted territories when it comes to doing the "impossible". More to come from Synergy Overdrive

 

I'll be interested to find out how much punishment MG1 can take with that turbo ICE.

 

Just curious, what is this claim based upon? I hope it is not an extrapolation from experience with an Otto-cycle engine, as the different cycle changes things.

 

This is awesome.

If I got more utility out of it, I would go for the hp. But the extra $3k in gas anually for a car that gets 17 to 22MPG like a WRX STI or any other cheap supercar always seams like a surf trip to Indonesia or a ski Trip to france or fishing in Puerto Vallarta foregon, pay for insurance, pay for a mortgage, health care, or anything besides 2-3x the $ amount anually I would spend in a Prius on gasoline. Well you get the picture, guess I am just too cheap for the ponies. Let's just say the Prii are not for the performance enthusiasts. The lil'Prissy is for those of us who like the minimum input of hydrocarbons and low emissions while being able to afford to go places and do things.

If I was a track junky, that WRX STI would give me a lot of bang for my buck and great handling in bad conditions... hmmmm.

We still have the big bottom end torque. There is always the diesel route for torque and a few more horses than the Prius. The 2.0L TDI Jetta has about 140Hp and 246 LbFt of Torque. You still won't get the Prius efficiency and emissions, but you will get a faster car with a lot of torque and a bonus of modern "clean diesel" urea injection technology to scrub the exhaust.

The Prius comfort and convenience is easy to get to love unless you have dreams of driving 720HP red Ferraris for the likes of C&D, R&T, or just have a sicophantic love for the blokes on TopGear. :cheer2: And that is cool too, but you wouldn't be on PriusChat if that was your M.O.

:focus:Also the 1.5L Gen II non-atkinson was planted with higher HP in the XB and XA from 04-06. You could probably bore, sleeve and supercharge one of those and get some high HP numbers (maybe 200HP?) before blowing the lil'fella up.

It is a sacrifice. Like sheeplover above noted, you gotta sacrifice the emissions and efficiency for the HP.

 

Should have had a Gremlin...or at least a V-8!

The Prissy will always be the Prissy. By any other name it isn't getting 40,45,50,55 mpg at least for a few more years.

With the Diesel/Electric combo you have all the torque in the world. Who needs high end HP anyways when your stuck in traffic most of the time?

Maybe that diesel hybrid Peugot will open new performance doors, but don't count on reliablility. And you'll have to move to Europe or bring it in under the radar. Peugeot To Show First Production Diesel Hybrid, For Europe Only - Green Car Reports

Maybe the blu-tec Benz?
Diesel Hybrids From Peugeot and Mercedes Get Closer to Reality - International Business Times Blogs

 

Do you have a thread started for this turbo mod? I am looking forward to the post. Can't wait to see your performance/efficiency numbers. Interesting indeed.

 

Guess this one didn't work either...2006 Toyota Highlander Turbo-Hybrid Sport by Borg-Warner - Performance Road Test - Truck Trend

 

My question seems to fit here.

As I understand the basics of the Atkinson cycle engine, at least one aspect is that the intake valve opens and permits a small amout of compressed fuel/air mixture to return to the intake plennum. IF that is correct ..... 1) is this accomplished solely with cam timing? Or is an Atkinson cycle engine a unique creation ... I know it is based on other Toyota engines, but are there other major differences other than the cam?
2) IF my understanding is correct ... is there a potential for explosion in the plennum with fuel/air under turbocharged pressure? We have all seen dragsters where the top blows off the engine when a valve floats and permits cumbustion gases back into the blower. I know they use nitro fuel, so maybe it is just much more explosive?

 

The piston bore is off center to the head and crankshaft.

 

Is there any connection between this and 'Atkinson Cycle', or is this something that could be done with any engine?

 

fuzzy1 - Hopefully someone more knowledgable will respond to your question, but as I understand it, the Atkinson cycle is, at least to some degree, how Toyota created a economical and environmentally clean ICE. The trade-off is lower power per cubic inch.... which is what the question was with this thread in the beginning. Customary hot rod mods, compression, valve timing and other tricks, work against the balance ..... more HP yes, but lower efficiency and greater emissions.

It would be interesting to know (and I don't) but I wonder if 50 mpg for a family sedan might be a barrier (like the sound barrier was for aircraft) that will be difficult to improve upon. I am very confident that with the years of experience Toyota has had with hybrids .... if they could have achieved 55 mpg, or 60 mpg or more, they would have done it with the G3. To achieve 50 mpg they had to resort to other fuel saving concepts .... such as the weight saving body panels, belly panels,tires, low wind resistance profile, electric A/C and water pump, tuned exhaust manifold and etc. There is so much sophisication in the entire design.

 

One 'interesting' feature of the Atkinson Cycle is that the compression ratio and the expansion ratio are asymmetric, where in the Otto cycle they are symmetric. I suspect the offset cylinder bores aid the asymmetry, as does the late intake valve closing.

 

IIRC

The off center crankshaft is to reduce friction between the piston and the cylinder wall on the downward power stroke that follows ignition.

Offsetting the crank makes the position of the connecting rod more vertical on the power stroke thus reducing the lateral force against the cylinder wall and the friction that results from it.

The benefit of the offset crank would also apply to other engine cycles.

The key thing that distinguishes the current "Atkinson" cycle is that closure of the intake valve is delayed until some of the charge can escape back through the intake valve thus lowering the degree of charge compression by enough to use standard octane fuel yet retaining the efficiency advantage of a high expansion ratio on the power stroke.

I'm sure that there are some forum members who have better knowledge in this area. Please feel free to correct the above as appropriate.

 

I very much doubt it. See 'Better Mileage Now", Scientific American, Feb. 2010, pg. 50. The author is a Honda VP.

Page 52 has a laundry list of improvements studied recently by NHTSA. Prius has only half of them, leaving room for another 20 to 35% improvement from this list alone.

I thought that the asymmetric compression / expansion ratio was the primary feature that we care about, as it greatly reduces pumping loss in partial throttle operation -- i.e. nearly all of the time. The late intake valve closing is what allows this ratio difference, and making it variable allows tuning on the fly for better efficiency.

Other commentary indicated that the offset bore is intended to reduce cylinder wall friction during the power stroke. When pressure is at its highest, the piston rod is at it straightest, putting the least lateral force on the wall. This could also be put into an Otto engine, without changing it into another cycle type.

 

fuzzy1 - Thanks ... I will go to the library and see if I can read the article you mention. Truthfully, we all could vastly improve our fuel efficiency if we would slow down. But I do not see that occurring.