Prius Supercharger?

I suspect that there's nothing you can do to increase the HP of the Prius. Everything is so finely controlled by the computer, and the electric and gas components are so seamlessly integrated. I also suspect that the Prius is not a suitable platform for horsepower enhancements. It just wasn't designed with that in mind. The Prius's strong points are its super-ultra-low emissions and its high mileage. If you need a car with more horsepower, and you are not concerned about emissions or mileage, I honestly think the Prius is the wrong car for you. There are plenty of other cars with lots more power, and frankly, some of them have more sporty handling, which you'd probably want along with the power.

 

Sadly, there is nothing available. There was a one off turbo Prius, but nothing available to consumers. At least there are handling parts, though!

 

Seems to me that if you want a "muscle car," you should buy one. The Prius' design and engineering goals are markedly different than those found in the "horsepower" cars.

 

Wow, tough crowd, seems like the poor guy wants a little bit of the power world brought into his economy world, I can't say I wouldn't like a bit more power either. I have days when my right foot is a little heavier than the normal Prius demographic, and on those days it would be great to have a little more power. My guess is he doesn't want to be the "Hybrid Driver" going for Max MPG that people complain about on the road. Ever heard of "Hybrid Rage"? Come to California and try to merge onto a freeway in a Prius, seems people don't care that you are doing at least as fast as they are, try to merge in a full size Bronco and people get out of my way. Can't say its a Prius thing but makes me wonder.

Al...

 

<div class='quotetop'>QUOTE(Alrobot @ Apr 18 2007, 03:28 PM) [snapback]425616[/snapback]</div>

And those people will have no idea whether he's got extra horsepower or not. They'll see the car and react as they usually do.

I think this whole idea is a waste of time. Toyota fine-tuned everything they could to produce the Prius. You want to change something? Start with a simpler power train.

 

I wonder how much just changing back to the Otto cam would gain...
The Echo [non-atkinson] is supposedly good for what, 130 hp?
.
_H*

 

<div class='quotetop'>QUOTE(hobbit @ Apr 18 2007, 06:02 PM) [snapback]425636[/snapback]</div>

But then you're in trouble compression-wise, aren't you, 'cause the Atkinson mill has a mechanical compression ratio of something on the order of 13:1, doesn't it?

This, if I'm correct, sounds like it would make forced induction problematic as well.

It appears to me that you'd need to change out the reciprocating parts or swap in an Echo/Yaris(?) shortblock, then keep the Prius head and all the special valvetrain stuff, with the exception of the cam, which would have a 'normal' grind...?

I, too, contemplated something like this a while ago and kept coming up with the same answer: buy a salvaged Prius and drop in a small block V-8!

Either that or tweak the suspension, so you can carry more speed through the corners.

 

<div class='quotetop'>QUOTE(daniel @ Apr 18 2007, 02:04 AM) [snapback]425167[/snapback]</div>

You know, I'm not sure I agree with that. From a mechanical standpoint the Prius gearbox (Power Split Device) is so insanely simple that it would probably be better than the automatic or manual gearbox in your average compact sedan. Without all of the friction parts you would have to start bending metal in order to fail it. Only hitch is whether or not the motor-generators can shuffle enough power to maintain gear ratios under dramatically increased load? Probably, but up to what point I don't know.

The problem with forced induction is that you can't just bolt on a supercharger and tear it up. The ECU needs to know about all that extra air and know how to inject enough fuel to keep up with it. The stock ECU won't do that, and I'd be willing to bet that the programming in this ECU is one of the most complex you can find. There might be a work around but it would take some serious engineering effort to get there.

 

<div class='quotetop'>QUOTE(UNWIRED @ Apr 18 2007, 01:09 AM) [snapback]425131[/snapback]</div>

Check the threads, I read about someone putting a turbo on a <2003 model and it worked well. If I remember right, it was designed for the Corolla, but fit perfectly.

 

I'm surprised no one mentioned a bigger engine. Obviously Toyota thinks HP is an issue with the current generation Prius, since it allegedly plans to offer a 2.0 ICE (up from the current 1.5) in the next gen Pree.

I'm not sure if a larger engine would even fit, but that's where I would begin. The fun part with any of that would be the software as it expects certain parameters.

Good luck.

 

<div class='quotetop'>QUOTE(allargon @ Apr 19 2007, 12:18 AM) [snapback]425864[/snapback]</div>

I considered this (perhaps naively), but wouldn't an engine swap necessarily disable some of the unique features of the current engine, specifically the valvetrain, which allow it to work in harmony with the rest of the powertrain? I guess that's where I'm a bit confused; you'd be gettting rid of the actual hardware which makes the ICE work with the rest of the HSD, wouldn't you?

I guess you could drop in a conventional transaxle and that 1.8 or another engine from a Toyota which shares its front suspension with the Prius (this is how I'm thinking about it, not knowing the ins and out of Toyota engines and platform sharing, etc.), but unless the added torque from the MG's could also be added, wouldn't we be back to a midsize four door automobile powered by a 1.8 liter four cylinder...?

Regarding the turbo: yes, it was done (although the people who did it, I recall, had to admit that it was a *lot* of work!) but I'm not aware of it being done with close to their success since then, which is interesting.

I think the Prius has theoretical potential for more performance, but the realities of the 'synergy' part of the HSD make it difficult to tweak.

Being more comfortable with a broadaxe than a scalpel, I suppose, I'd probably still be inclined to find a salvaged prius that's had driveline parts already removed and build a nice little V8 Prius.

Hmmmm...

Perhaps a 455-cid V8 and transaxle from one of those front-wheel-drive Olds Toronados from the mid-60's (or, one of those classic 6-wheeled GM motorhomes from the 70's!), in a mid-engine configuration, somewhere behind the front seats (a la Renault R5)...?

I *do* love a four door hatchback!
[laughing]

 

<div class='quotetop'>QUOTE(brick @ Apr 18 2007, 04:42 PM) [snapback]425663[/snapback]</div>

Mechanically, the PSD is indeed much more simple, and in my opinion, categorically better, in every respect. However, the PSD in the Prius is a TINY little thing. Frank showed us one at the alternative fuel fair in Lacey last year.

In my opinion, if the Prius doesn't have enough power for you, consider one of Toyota's bigger hybrid cars. The Prius was designed, from bottom up, to do what it does, and to have the power it has. It sounds like the 2009 will be more powerful and have other advantages as well, including better mileage, which it will accomplish by incorporating newer technology. I think you'd be better off waiting to buy that, than messing with the current Prius.

Just my opinion.

 

Here is another idea:

If your objective is to improve 0-60 full throttle acceleration, and if you are willing to sacrifice top speed and fuel economy, then you could do so by changing the ratio of the gearbox.

Increasing the gear ratio would have two effects:
First, the torque from both the ICE and MG2 to the wheels would be increased.
Second, the ICE would reach the rpm of maximum power sooner.

Below about 60 mph, the maximum attainable rpm of the ICE is limited by MG1, which can't be let to run "backwards" fast enough, and by the wheels, which are not yet turning fast enough to allow the ICE to reach its maximum rpm.
So the ICE cannot rev up to maximum horsepower until the Prius reaches about 60 mph.

At about 60 mph and above, there would be no more advantage, because the HSD would keep the ICE rpm and thus the overall ratio the same in both cases. And, with increasing speed, the electric motors would max out sooner with the higher gear ratio, thus decreasing top speed.

All it would take to do this would be to replace one or two pairs of gears.
That is; IF you can find a good machine shop that can make high quality custom gears, and IF you can afford it, and IF the new gears fit into the gearbox. (big IFs)
That would be the time consuming, but elegant engineering solution.

The quick and dirty method, although I would not recommend it, would be to mount low profile tires that have a smaller circumference. The disadvantages of that would be inaccurate speed, odometer and mileage indications, less ground clearance, harsher ride, and the little tires would look funny.

 

All,

My favorite approach to increasing Prius performance is to add "hub motors" to the rear wheels, a second battery pack, and power electronics/computer. This would add about 20 kW (or about 30 HP - the NiMh battery 100 amp current limit), provide pseudo 4-wheel drive and "fix" the Prius overzealous traction control problem.

Estimated cost:

• $750 - salvage Prius 200 v battery pack
• $1000 - hub motors (estimate)
• $500 - Motor speed control electronics (matched to hub motors and 200v battery)
• $1000 - on board computer

This totals just over $3k but doesn't include many hours of custom engineering effort (its a hobby - right?)

Note the similar approach used by Toyota in its performance hybrids (Highlander, Lexus ...)

JeffD

 

Nitrous? :blink:

 

The guys at quantum have turbos in their prii.. It's a really rough ride, but they did manage to tweak the firmware enough to make it work..
It's probably not what you want though. You can count the number of fueling stations with your fingers and toes though.. Ermm. did I mention that they don't run on unleaded gasoline?

http://www.greencarcongress.com/2006/01/qu..._deliver_1.html