More HP? Can it be done?

Hi Javinos,

The total Prius power rating is 110 hp. But also, the car does not waste time shifting, so that saves a second up to 60 mph. Remember you have a 30+ hp battery under the rear seat.

I doubt the difference in power is more compression. The Prius is already 13:1 expansion ratio, with variable compression ratio (achieved through variable valve timing). The difference is probably related to the cam. It could have more overlap to optimize the higher RPM in the echo engine. The Prius engine max RPM is 5500, whereas I would expect the Echo engine is 6500 rpm.

I think a more straightforward way to improve power would be a small turbo-charger. If its the right size it might benefit both mileage and power. An aussie on-line car magazine editor did this to a Generation 1 Prius. He found the system controlled the turbo engine just fine, and it became a much better hill climbing car, but was not otherwise impressive. There is lots of room back behind the engine there. I think they made room for the Turbo in the initial design. The next generation Prius is to be turbo-charged according to on-line reports.

Although you might want to keep your A/C Compresser their in Puerto Rico, but one could think about using the A/C Compressor power to run three-phase brushless DC motor driven supercharger. Although not sure how to hack the A/C controls to get max RPM on demand. The A/C compressor is speed controlled, so the supercharger could be too, which might be tunable for fuel economy and power.

 

76 hp is the output of the ICE alone. It is more efficient but less powerful than the Yaris engine because it uses an Atkinson Cycle instead of the standard Otto Cycle.

 

<div class='quotetop'>QUOTE(donee @ Mar 10 2007, 10:04 AM) [snapback]403339[/snapback]</div>

Classic Prius max ICE RPM is 4,500.
04 Prius max ICE RPM is 5,000.

 

Sts turbo sytems, manufactures a turbo that replaces the muffler.Plenty of room back there.

 

Modifying the engine is probably a waste of time and money for the gain. Replacing it, along with the transmission, is possible.

I'd recommend going the "Wolf in Rabbit's Clothing" route though.

Someone took a Rabbit and dropped the body on a Porsche 9-11 frame.

Just take your Prius body and drop it on a Boxter frame or some such. Then you can have the hottest Prius around if that's what floats your boat.

 

Getting an engine to produce more power is not a hard task as long as one knows that obviously to do so requires more fuel and the more fuel you add the more your MPG goes down, QUICKLY!!

A while back I put my 05 Prius on our Dynojet chassis dyno and posted the results here. In order to modify the car's engine you first have to have access to reprogram the PCM in order to richen the fuel mixture and advance/retard the ignition timing. I don't think anyone other than the factory has such tools at their disposal.

The bottom line is that in a car like the Prius, maximum hp was not the designers intent but sufficient power and excellent gas milage was. In addition, the Prius was designed to be a "green" car and as such keeping emissions to an absolute minimum.

 

If the compression ratio truly is 13:1 then you'd need to drop it before just adding a turbo.

First post, great looking forum, should get my touring model withing the next 2 days!

 

<div class='quotetop'>QUOTE(Bert Fenenga @ Apr 2 2007, 03:06 AM) [snapback]416325[/snapback]</div>

Bert,

The true compression ratio is not 13:1. It is much lower due to the valve timing. The intake valves remain open or the first part of the compression stroke. This is what makes it an "Atkinson Cycle" engine.

Adding a small amount of turbo pressure would prevent some of the backflow of fuel mixture into the intake manifold. This was done in a "Classic" Prius with good (perhaps not enough to be worth the effort) results a few years ago.

JeffD

 

If that's the case then it would make sense to do a turbo install. I can't imagine it would sap that much fuel if you're not into it heavily, and it's available when you need it. What would really be a cool idea is a cutoff switch for the turbo, only flip it when you need it.

 

AutoSpeed - Technokill: Building a Blown Hybrid, Part 1

http://autospeed.drive.com.au/cms/A_2567/article.html

Site is down at this moment, but I've been there a few times so expect/hope this is temporary. Summary is that yes you can add a blower/turbo but with the way power is managed by the computer, you won't notice that as more acceleration, but will keep your MG boost always available by keeping the battery topped off even under long heavy loads.