The WOW look at this thread

Thread Tools
 
Search this Thread
 
Old Sep 6, 2005 | 03:16 PM
  #2521  
laoba's Avatar
VIP Member
iTrader: (4)
 
Joined: Nov 2004
Posts: 6,136
From: <3 tai mei
Car Info: rx8
subaru legacy hybrid



it's a 2.0L that puts out about 256HP and gets 38.3 mpg.


Fuji Heavy Industries’ (FHI) new Subaru hybrid (earlier post) will use a thin 10-kW motor in combination with the 2.0-liter 16-valve twin-scroll turbo engine currently used in the Legacy to create the Turbo Parallel Hybrid (TPH) powertrain.

The combination of the motor generator and Subaru’s Boxer turbo engine, which is adopting the Miller cycle in this application, creates a motor-assist hybrid (similar in concept to the first generation of Honda IMA) that FHI hopes will provide the performance of the current 2.0 Legacy GT (turbo) while delivering a 20% improvement in fuel consumption.

Compared to the SSHEV (Sequential Series Hybrid) system that FHI had previously developed and shown in 2003, the TPH uses a much smaller, compact motor and a smaller battery—also reducing the system cost.

A Boxer engine is horizontally opposed engine—i.e., the pistons lie in a horizontal plane, with pairs of cylinders on the left and the right, as opposed to engines where all pistons are inline, or positioned in a V.

The Boxer design ideally provides perfect balance because each piston’s movement is exactly counterbalanced by the corresponding piston movement of the opposite side. Subaru uses Boxer engines in all its cars.

The basis for the TPH engine is the turbo EJ20 currently being used in the Legacy. This engine comes equipped with Active Valve Control System (AVCS), but the TPH engine will specially modify the valve timing to implement the Miller cycle.

The Miller cycle, developed in the 1940s (by Ralph Miller), is a modification of the basic Otto four-stroke combustion cycle. Later adapted for use in cars—notably by Mazda in the Millenia—the Miller cycle is similar in approach to the Atkinson cycle engine used by Ford in the hybrid Escape and Mariner, with one major difference.

In both Atkinson and Miller cycles, the engine leaves the intake valves open during the beginning of the compression stroke. This pushes part of the charge back out the normally closed valve.

The late closing of the intake valve eliminates the substantial amount of energy normally required to overcome friction (as well as pumping losses) in the process of completing a normal compression stroke.

Put another way, the benefit of this is that the compression stroke effectively becomes shorter than the expansion stroke. The compression work starts when the valve is closed, so the piston gets all the compression for a percentage of the normal work. The result is increased engine efficiency, at around 10%–15%, although with a loss of power.

In the prototypic Miller configuration, however, a supercharger over-feeds the cylinder to compensate for the loss or blowout of charge.

Subaru, however, is not using a belt-driven supercharger with its TPH-Miller cycle engine, but rather a turbocharger, with which it has years of experience in its car lines. Because the turbine’s output decreases as a result of the Miller cycle, the TPH turbine has been designed to provide higher flow than normal.

As shown in Volkswagen’s design work on its dual-charged TSI engines (earlier post), turbochargers are good at higher speeds, but lack in boost at low-engine speed ranges. Without the supercharger to provide low-speed boost, the Miller engine would deliver relatively poor low-end torque.

To provide that low-speed boost, Subaru is turning instead to the electric motor in its hybrid powertrain.

The 10-kW electric motor provides 150 Nm of torque. (Subaru is proud of its higher torque spec. Compare that to the 14-kW motor providing 135 Nm of torque in the Honda Accord hybrid with a larger 3.0-liter engine. The about-to-be-released 2006 Civic hybrid, with a smaller 1.3-liter engine, uses a new 15-kW motor delivering 103 Nm of torque.)

Combining the Miller cycle and TPH systems will result in performance that matches the current 2.0 GT-turbo specs in the Legacy, while providing an approximate 20% improvement in fuel economy, according to FHI.

The current non-hybrid 2.0 turbo Legacy (sold in Japan, the US only offers the 2.5-liter version) delivers 191 kW (256 hp) and 343 Nm of torque. On a combined Japanese cycle, it consumes 7.69 liters/100km, or about 30.6 mpg US.

Applying the 20% hybrid factor to those numbers would yield comparable performance, but at 6.15 liters/100km—or 38.3 mpg US.
Old Sep 6, 2005 | 05:13 PM
  #2522  
c279a's Avatar
VIP Member
iTrader: (9)
 
Joined: Jul 2004
Posts: 12,243
From: ?
Car Info: FORD PINTO
Originally Posted by 1reguL8NSTi
I've gotta do something to keep my mind off this place. Thanks Ruben.

that's alright....at least my stuff wasn't washed away.......
Old Sep 6, 2005 | 11:15 PM
  #2523  
1reguL8NSTi's Avatar
Registered User
 
Joined: Jan 2005
Posts: 9,198
From: I gotta have more cow bell!!!!
Car Info: 05 STi
Originally Posted by c279a
that's alright....at least my stuff wasn't washed away.......
Ruben, don't player hate because the Prelude is still alive and well.
Old Sep 6, 2005 | 11:17 PM
  #2524  
c279a's Avatar
VIP Member
iTrader: (9)
 
Joined: Jul 2004
Posts: 12,243
From: ?
Car Info: FORD PINTO
who wishes their girlfriends can do this?....
Old Sep 6, 2005 | 11:26 PM
  #2525  
c279a's Avatar
VIP Member
iTrader: (9)
 
Joined: Jul 2004
Posts: 12,243
From: ?
Car Info: FORD PINTO
this girl looks like she's had a little too much to drink

Old Sep 6, 2005 | 11:59 PM
  #2526  
c279a's Avatar
VIP Member
iTrader: (9)
 
Joined: Jul 2004
Posts: 12,243
From: ?
Car Info: FORD PINTO
Old Sep 7, 2005 | 12:28 AM
  #2527  
gc8 pimp's Avatar
VIP Member
 
Joined: Dec 2002
Posts: 1,106
From: teh OC
Car Info: GC8 v5 Impreza
Originally Posted by c279a
who wishes their girlfriends can do this?....
Wow. So many possibilities. Makes it a little more interesting.
Old Sep 7, 2005 | 07:07 AM
  #2528  
BLITZSTI's Avatar
VIP Member
iTrader: (2)
 
Joined: May 2004
Posts: 10,752
From: WATCH OUT FOR THE SCIC SNITCH!!!
Car Info: .
you sick *** bastards! thats a kid!
Old Sep 7, 2005 | 07:30 AM
  #2529  
soggynoodles's Avatar
Token Toyota Mod
iTrader: (50)
 
Joined: Jun 2004
Posts: 52,306
From: Palo Alto, CA
Car Info: Something german
Originally Posted by BLITZSTI
you sick *** bastards! thats a kid!
ewww it is!

Just buy my vf34 Ruben and the Preludes will stop bugging ya.

I'm thinking of getting a bigger turbo.
Old Sep 7, 2005 | 07:49 AM
  #2530  
BLITZSTI's Avatar
VIP Member
iTrader: (2)
 
Joined: May 2004
Posts: 10,752
From: WATCH OUT FOR THE SCIC SNITCH!!!
Car Info: .
Originally Posted by soggynoodles
ewww it is!

Just buy my vf34 Ruben and the Preludes will stop bugging ya.

I'm thinking of getting a bigger turbo.
it doesnt matter what he has if he keeps sitting like this guy

Old Sep 7, 2005 | 09:07 AM
  #2531  
soggynoodles's Avatar
Token Toyota Mod
iTrader: (50)
 
Joined: Jun 2004
Posts: 52,306
From: Palo Alto, CA
Car Info: Something german
Originally Posted by BLITZSTI
it doesnt matter what he has if he keeps sitting like this guy

hahha he leans back in his car while he drives?!?!?
hahaha
Old Sep 7, 2005 | 09:27 AM
  #2532  
BLITZSTI's Avatar
VIP Member
iTrader: (2)
 
Joined: May 2004
Posts: 10,752
From: WATCH OUT FOR THE SCIC SNITCH!!!
Car Info: .
Originally Posted by soggynoodles
hahha he leans back in his car while he drives?!?!?
hahaha
he still denies it. but when you can barely reach the top of the steering wheel and your shoulder blades dont even touch the seat... youre sitting too low. i guess hes driving like those crazy peruvians
Old Sep 7, 2005 | 09:58 AM
  #2533  
soggynoodles's Avatar
Token Toyota Mod
iTrader: (50)
 
Joined: Jun 2004
Posts: 52,306
From: Palo Alto, CA
Car Info: Something german
Originally Posted by BLITZSTI
he still denies it. but when you can barely reach the top of the steering wheel and your shoulder blades dont even touch the seat... youre sitting too low. i guess hes driving like those crazy peruvians
He should buy a Recaro set then. That'll teach em.

Take a picture next time and post it though.

I need a good laugh.
Old Sep 7, 2005 | 10:10 AM
  #2534  
BLITZSTI's Avatar
VIP Member
iTrader: (2)
 
Joined: May 2004
Posts: 10,752
From: WATCH OUT FOR THE SCIC SNITCH!!!
Car Info: .
Originally Posted by soggynoodles
He should buy a Recaro set then. That'll teach em.

Take a picture next time and post it though.

I need a good laugh.
more like wood chair..
Old Sep 7, 2005 | 01:29 PM
  #2535  
BLITZSTI's Avatar
VIP Member
iTrader: (2)
 
Joined: May 2004
Posts: 10,752
From: WATCH OUT FOR THE SCIC SNITCH!!!
Car Info: .
still my all time favorite! colin mcrae



All times are GMT -7. The time now is 05:52 PM.