Prius Pistons

[xnamerxx]

Originally Posted by cali yaris

I don't see any baffling in the large picture that xnamerx posted. The inside of the cutout intake manifold is shown in blue, right? Looks pretty smooth and open.

What's the purpose of a different manifold?

off-topic. How difficult would it be to transplant my motor/trans into a Prius?

Atkinson cycle engines don't have large powerbands but rather a small efficiency zone, so whereas a traditional otto engine is probably about 27-33% efficient between 2-5.5k a Atkinson engine is 35-39% efficient between 4-4.5 rpms. So because it uses a hybrid drive transmission the engine never really cycles through its rpm range but rather like a CVT just has a gearing change that keeps the engine happy but still allows acceleration while the electric engine is providing the majority of the mechanical drive.

I don't think the transmission bolts up to the 1nz-fxe, it would be far simpler to get an electric engine/generator and attach it to the crank snout like a supercharger to get some extra assist that way. That kinda the way honda currently does it with the CRZ/Insite

[JustDidIt]

Originally Posted by xnamerxx

Atkinson cycle engines don't have large powerbands but rather a small efficiency zone, so whereas a traditional otto engine is probably about 27-33% efficient between 2-5.5k a Atkinson engine is 35-39% efficient between 4-4.5 rpms. So because it uses a hybrid drive transmission the engine never really cycles through its rpm range but rather like a CVT just has a gearing change that keeps the engine happy but still allows acceleration while the electric engine is providing the majority of the mechanical drive

I don't 'feel' my Prius engine at all under 3000k but the usable rpm looks to be about 3000-5500. Swapping the cams yet keeping my pistons will essentially switch me over to otto cycle with a touch of compression increase.

[xnamerxx]

I can almost guarantee you, you'd be doing more harm then good by swapping to otto cycle cams in your engine. The prius is mainly powered by the electric engine, so to make that as efficient as possible the torque output on the gas engine needs remain a constant. The numbers I listed were WAG and so probably not accurate. Remember your gas engine isn't directly connected to the wheels, so its RPM's are also not a contant

Here is a website that explains how the HSD powersplit device works. Website

Upping the power on the gas engine doesn't help as much as you'd think since only torque at certain rpms provides assist. Since the engine only revs to 5k you'll be throwing away all the constant torque of the fxe to gain the peak torque of the fe all with major loss and no benefits. You have to think of the gas engine as a electricity generator/backup power unit rather than a PU. You can rev the nuts off the Prius engine and the car won't move unless the electric motor is moving.

[JustDidIt]

Originally Posted by xnamerxx

I can almost guarantee you, you'd be doing more harm then good by swapping to otto cycle cams in your engine. The prius is mainly powered by the electric engine, so to make that as efficient as possible the torque output on the gas engine needs remain a constant. The numbers I listed were WAG and so probably not accurate. Remember your gas engine isn't directly connected to the wheels, so its RPM's are also not a contant

Here is a website that explains how the HSD powersplit device works. Website

Upping the power on the gas engine doesn't help as much as you'd think since only torque at certain rpms provides assist. Since the engine only revs to 5k you'll be throwing away all the constant torque of the fxe to gain the peak torque of the fe all with major loss and no benefits. You have to think of the gas engine as a electricity generator/backup power unit rather than a PU. You can rev the nuts off the Prius engine and the car won't move unless the electric motor is moving.

TRD did it... with the Otto swap..

Originally Posted by JustDidIt

.....Motor transplant shouldn't be difficult and was done by the Bonneville Landspeed Prius. They swapped the Otto Cycle 1NZ-FE from an Toyota Echo in but didn't do the Prius pistons swap. I'm looking to do both.

Originally Posted by xnamerxx

You can rev the nuts off the Prius engine and the car won't move unless the electric motor is moving.

Not completely true...when the battery doesn't have enough juice to run the MG2, u can feel ONLY the gas engine struggling to push/pull the car along. With the battery charged enough from the regenerative braking from MG1, MG2 kicks in to assist the gas motor also boosting the inverter from 220v up to 500v.

[xnamerxx]

I don't think I've heard of the TRD Prius for one, I've heard of that random guy who build the Bonneville Prius and the really unsuccessful FSP Prius. For the Bonneville Prius using Otto cams helps move the powerband up which would help for top speed runs which require taller gearing.

[JustDidIt]

Originally Posted by xnamerxx

I don't think I've heard of the TRD Prius for one, I've heard of that random guy who build the Bonneville Prius and the really unsuccessful FSP Prius. For the Bonneville Prius using Otto cams helps move the powerband up which would help for top speed runs which require taller gearing.

I was referring the to Bonneville Prius...and I'm pretty sure these guys weren't random...

Toyota's Landspeed Prius gas-electric hybrid vehicle debuted in Bonneville, Utah as the first production hybrid to race across the Bonneville Salt Flats. The advanced technology of the popular hybrid mid-size sedan was taken to another level as Car and Driver editor Aaron Robinson drove the modified Prius on the three-mile short course, and set a hybrid record speed of 130.794 miles per hour. Other Landspeed Prius drivers included Prius executive chief engineer Shigeyuki Hori, and Fumiaki Kobayashi, group vice president technical and regulatory affairs, Toyota Motor North America, Inc. A Bonneville veteran Jim Leininger, a Toyota field product engineer, served as crew chief, while Dr. Hori kept a watchful eye on the project The Landspeed Prius' historical run also paved the way for a hybrid class to run at Bonneville.

(1.5L otto cycle motor swap from echo, modified intake routing, JDM TRD ECU, inverter upgrade, final gear changes, transmission cooling system, custom 1-off suspension, larger front diameter tires and custom exhaust)

Bonneville LandSpeed specs:

The Landspeed Prius ran a stock "Hybrid Synergy Drive" powertrain, which integrates a large electric motor with a 1.5-liter gasoline engine. The transmission final drive gear ratio for the gas engine was modified from the stock 4.23:1 to 3.2, while the inverter voltage was increased to 550 volts from 500 volts. The engine redline was also changed for optimum performance.

A transmission cooling system was added to the front passenger area to decrease the temperature of the inverter and electric motors and maximize efficiency. Regular ice was constantly added to the system to prevent overheating. Ambient temperature on the salt flats was nearly 100 degrees with nearly 100 degrees humidity.

Other modifications included the removal of the interior, the addition of a roll cage and lowering the suspension five inches for improved aerodynamics. The Landspeed Prius incorporates custom Bilstein shocks and Eibach springs. The inner fender wells were also altered to accommodate the lowered ride height.

The Landspeed Prius is equipped with unique 26-inch front and 25-inch rear Goodyear Eagle Landspeed Record tires.

To prepare for Bonneville's race environment the Landspeed Prius had a removable front tow bar and rear pushbar installed to assist the vehicle to the track.

Toyota will display the Landspeed Prius at the 2005 North American International Auto Show in Detroit.

ENGINE

* Gasoline Engine 1.5-liter, 4-cylinder, twin-cam, DOHC 16-valve
EFI with VVT-i, aluminum-alloy block and head

* Torque 97 lb.-ft. @ 4,200 rpm

* Horsepower 96 hp @ 5,800 rpm

ELECTRIC MOTOR/GENERATOR/POWER STORAGE

* Motor Type Permanent Magnet Synchronous Motor

* Electric Motor Power Output 50kW/1,2000 - 1,540 rpm

* Torque 295 lb.-ft. @ 1-1,200 rpm

* Battery type Nickel-metal hydride

* System voltage 550 volts maximum from original 500

SUSPENSION
* Front Independent MacPherson strut suspension with
stabilizer bar Eibach Racing coil springs,
Bilstein shock absorbers

* Rear Torsion Beam with stabilizer bar, Eibach
Racing coil springs, Bilstein shock absorbers

* Tires 25 and 26-inch Goodyear Eagle Landspeed Record tires

SCCA Solo2 F Street Prepared Prius Specs:

This basic fact sheet covers the F street Prepared 2004 Prius team layout, modifications and basic vehicle specifications. This is a preliminary fact sheet and subject to changes and/or revisions.

Team:
Owner/ Crew chief- Jim Leininger

Owner/ Driver- Matt Leininger
Co-driver/ fabricator- Mike Nakata

Logistics and back-up driver- Jose Alfaro

Modifications:

Drivetrain: Engine: Internal- Stock
External- modified intake routing in style of Toyota Motorsports Bonneville Prius. Further modified ECU controls (hi rpm redline, altered fuel and spark map) under development. TRD Yaris Header, Custom intake manifold w/ large bore thottle body under development.
Transaxle: Custom Weismann 1-way locking differential


Chassis: Interior: Motorsports Technical Center 6-point chromoly bolt in roll cage, Sparco Corsa racing seats, custom seat tracks; Sparco 383 Suede Steering wheel w/ billet touring car quick disconnect.

Exterior: TRD Japan front spoiler, TRD Japan custom flared front fenders. Custom rolled rear fenders. Custom graphics designed by Matt Leininger, applied by Molly Designs.

Suspension: Custom TRD USA adjustable coil over dampeners, tuned and valved by Progress Technologies. Eibach springs (325 lb/in front, 650 lb/in, rear). Front camber adjusters, modified rear sway bar.

Wheels: WedsSport Satin TC-005 one piece spun forged- 17x 8.5”, custom offset.

Tires: Dry- Hoosier AS305 225/45R17
Wet- Bridgestone RE750, shaved 225/45R17

Brakes: Modified Hawk Performance brake pads- “black compound”
Motul Synthetic hi-temp brake fluid.

Basic Specifications: Race weight, wet- 2772lbs (stock, dry- 2890lbs)
Weight distribution- 56/44 percent (stock, 59/41)
Overall height- 56.3in
Ground Clearence- 3.1in

[jetblast]

Now if someone just rips open a Prius and magically finds Carillo, Pauter, or even Molnar rods attached to these pistons. In that case, key up the Mission Impossible theme music as I put on the black spandex from my early spy days. Into the local junkyard all night long to harvest the jewels.....hey, this spandex used to fit.

C'mon! I can dream!!!!!!

[JustDidIt]

Originally Posted by jetblast

Now if someone just rips open a Prius and magically finds Carillo, Pauter, or even Molnar rods attached to these pistons. In that case, key up the Mission Impossible theme music as I put on the black spandex from my early spy days. Into the local junkyard all night long to harvest the jewels.....hey, this spandex used to fit.

C'mon! I can dream!!!!!!

Thats the spirit!

[tooter]

It's fun to watch where this is heading...

[JustDidIt]

Originally Posted by tooter

It's fun to watch where this is heading...

I'm just"gonna"doit - I may wait on buying my wheels if I can get a better understanding of this otto swap concept. :) Still haven't heard back from my 1NZ head source. :(