Turbo for 2004 Prius

Steve, let me try again. :wink:

Something like this? >> Electric Supercharger "e-RAM"

 

Is the eRam safe to use in a Prius? From eRacing:

SAFE FOR YOUR ELECTRICAL SYSTEM: High current for short duration is drawn directly from your battery, not your alternator. Just like your starter motor.

I would be concerned that the 12V accessory battery could not handle such current draw, especially since the Prius was designed without a conventional starter motor. Instead MG1 (or is it MG2?) runs off the traction battery to start the engine.

This site seems to think little of electric superchargers due to their low static pressure power. This site shows that an one particular installation netted only a 3% gain in HP (eRacing advertises 5% and their performance guarantee states a range of 4-6%).

The first link also states the advantage of having a higher voltage system, allowing the use of thinner power wires for the motor. Since the Prius does have 201V and 500V power available, like even thinner wires or a more powerful motor could be used for an electric supercharger.

I like really like the idea of a electric supercharger for the Prius, but maybe eRam isn't the way to go, and maybe a more Prius specific electric supercharger (ideally) would be significantly better.

 

The only times a Prius could use this turbo would be at higher speeds (42mph+) when MG1/MG2 isn't really kicking in anymore right?

OTOH, why not just add in electric motors that are already geared to kick in past 42mph instead? Actually, it's too bad that at least MG2 isn't on some sort of CVT (or maybe 2-3 gear transmission) that's connected to the HSD that keeps it in its powerband through all speeds instead of a linear range that makes it less useful the closer it is to 10K and/or 100mph.

Sure having a "transmission" would mean some power losses through the gearing, but I think there's plenty to spare.

 

Steve-
Why do you look 30 in your avatar?

 

Although the 12V battery is something like 38AH, it is fused for 150A, unlike the DC/DC converter, which is fused for 100A. So, it should be able to provide current for a short while, like 15 minutes at least, and I doubt the turbo would pull more than the DC/DC converter could deliver.

 

E-Ram pulls 57A, super E-Ram pulls 112A.

 

Much as I am a proponent of supercharging, I expect that turbocharging is a better solution for a hybrid. The plusses and minusses of supercharging versus turbo-supercharging tend to favour the turbo when the application has the following criteria:

* space
* engine bay heat
* cost

The greatest weakness of the turbo is lag, but a hybrid has an electric torque source to create excellent throttle response while the turbo spools up, so I'd discount lag. I wouldn't completely ignore it, I'd still go for the smallest, most efficient and most responsive turbo I could apply.

The supercharger wins out when the application has the following critiera:

* maximum power
* torque
* no concern for energy efficiency

The parasitic loss of a blower is utterly antithetical to a hybrid. Turning a blower is a massive parasitic loss of energy and systems that overcome turning the blower are complicated and expensive.

Much as I'd prefer the free exhaust and the ultimate power of the blower, it's the turbo that makes sense for a hybrid. The power-plant could literally retain the same peak fuel efficiency, maintain the same averages and yet tap into tank-guzzling power if the driver asks for more power once the battery is depleted.

And a turbo kit should be around US$1K and take maybe ten hours to install. Conversely, the supercharger itself is at least US$2K and a kit will be US$3K with at least as many hours for installation.

The real kick in the pants is the emissions. If anyone has a California legal, CA emissions compliant, CARB complicant turbo kit for an '05 Prius, I'm a customer. Brake upgrades? Suspension and handling? Wheels and tyres? Warranty implications? Transmission durability? All good questions, but I'd still be tempted to go ahead and try.


Adam

 

<div class='quotetop'>QUOTE(Steve Goldenberg\";p=\"98219)</div>

The "e-ram" option is covered elsewhere in the forums. Suffice it to say that the e-ram has apparently been discredited on applications from miserly four cylinder econo-boxes to gas-guzzling SUVs and everything in between. I guess the air-flow through the electric compressor is interesting but not useful once it's trying to compress the air-flow entering an engine.
I think it's also fair to say that a high energy electric fan is the last thing the Prius wants to serve since its electric reserves are already taxed if the driver is asking for maximum power.

Given available technology to control boost, fuel and timing outside the factory engine management system, I'd look for a system that can be "plug and play" -- something that could be installed or removed easily and without impact.

Cheers,

 

Most turbos rely on engine oil to cool down their precision components. If the ICE shut off, the oil flow stops, and the turbo may be damaged.

This is why a supercharger seems like a better option.

Nate

 

Well, the turbo is cooled and lubricated by oil shared with the rest of the engine, but they only operate at the same time. Also, if the vehicle is stopping and starting the engine, it's in a driving situation where it's probably not drawing on the power of the engine, so it's not going to be using the turbo, so the heat build-up won't be as signficant.

Turbos work their hardest under continuous boost, plus, this application, unless the engine was modified to lower compression, would be a very low level of boost -- we're talking about the smallest possible turbo; squeezing maybe 0.5 bar? (roughly 7psi) so the turbo is going to have an easy life. There's also the option of running an intercooler (increasing the work-load of the turbo) but even that, for a 1.5l engine, just isn't going to make the turbo break a sweat.

In any turbo application, it's important to use synthetic oil, so the heat soak around the turbo bearings won't break down the lubricant.
The idea of "stop start" driving for a turbo doesn't sound like a great idea, but I've seen turbos in modern applications subjected to work that the Prius could never bring to bear on its little 1.5 litre lump.

 

i am looking to add a turbo to the prius not for more power but for more feul eff.

more air into the engine means to me a better burn and so less fuel needs to be taken in.

is this stupid or am i on a right track with this?

 

Let's simplify matters by stating that electric superchargers do not work. Period.

Superchargers are generally easier to install and less expensive depending on intercooler placement.

Turbochargers are much more complex yet yeild incredible results. Todays system exhibit very little "lag" when the compressor is sized correctly to the application yet a good turbo kit will cost you upwards of $3,000 without a new manifold and over $4,000 with a new manifold. The oil pump could be driven by an electric pump so when when the Prius engine is off oil can circulate through the turbo to prevent coking. This is how the STS Turbo system runs and IMO would be a neat way to package a turbo system for the Prius since the turbo could be located under the car in the rear.

That being stated I agree with BT Tech. The biggest problem you will run into is the Atkinson style engine and it's extremely high compression ratio on one side and it's low compression ratio on the the other. You would absolutely require ECU tuning (if there is a system that can tune ours)which usually runs $350-$500 at most dyno shops, larger injectors, larger fuel pump or an inline pusher style pump and a larger exhaust (if using a standard front-mount turbo or supercharger). I'm not sure what can be done on our fuel systems but this is what is required on any other car that installs aftermarket turbo systems.

I've owned and installed (or helped install):

Magnacharger Radix Supercharger
Powerdyne Supercharger
Vortech Supercharger
STS Rear-Mount Turbo
Custom Synergy Motorsports Twin-Turbo

Trust me when I say it is not super simple.

Radix


Installing intercooler for STS turbo kit


Vortech on my old 87' Mustang GT (it replaced my Powerdyne kit)


Synergy Motorsports twin kit

 

Assuming you were going the power route and were willing to give up the attributes of the Atkinson cycle, what are the possibilities of using an Echo engine? I've heard interesting rumours of these bolting on to the Prius HSD, which would change things considerably.