Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

Subaru is developing turbo hybrid for 2007


  • Please log in to reply
5 replies to this topic

#1 TheBrian

TheBrian

    Eat, Live, Breath Subaru

  • Members
  • 270 posts
  • Buffalo

Posted 15 September 2005 - 08:53 PM

I found this article, which says Subaru is developing an EJ20 turbo + hybrid, which they hope to put in a Legacy in 2007. It would compete against the likes of the Accord hybrid. They expect to beat the Accord hybrid by a few MPG.

The engine uses the Miller cycle, where forced induction over-fills the combustion chamber, but the intake valves are left open during the beginning of the compression stroke, to allow good fuel-air mixture. The torquey electric motor makes up for the lack of low-end torque on the part of the turbo Miller-cycle engine.

It's a pretty interesting article, and it's cool that Subaru is doing yet another thing a totally unusual way. I'm impressed with how quickly they expect to get this technology to market. If they do pull off the numbers they're talking about in 2007, they might just get the attention and brand recognition they crave.

#2 NoahDL88

NoahDL88

    Elite Master of Cookies

  • Members
  • 4,264 posts
  • Everett, WA, USA

Posted 15 September 2005 - 08:59 PM

Cool, i told my mom that she should get rid of that volvo for a Subie, she said " only if its a hybrid" i think we're in business now :grin:

#3 blitz

blitz

    Banned

  • Banned
  • 1,091 posts
  • Warren, Michigan

Posted 15 September 2005 - 09:35 PM

The Miller-cycle is interesting because it introduces the term "expansion ratio" as separate from the compression ratio.

Normally it is the increased expansion ratio (on the power stroke) that is the primary reason for the increased operating efficiency as a result of increasing the what would normally be refered to as the "compression ratio".

The miller cycle engines run static C.R.'s of around 13:1, but lowers the effective C.R. (compression pressure) to conventional levels by way of hanging the intake valves open longer to allow a partial reversion discharge. However the expansion ratio remains 13:1.

Not sure if that made sense. :confused:

#4 redwagon

redwagon

    New User

  • Members
  • PipPip
  • 16 posts
  • Taiwan

Posted 15 September 2005 - 10:45 PM

You can also consider turbocharging as a way of increasing the expansion ratio ;)

#5 Hondasucks

Hondasucks

    Subaru Technician

  • Members
  • 4,760 posts
  • Vancouver, WA

Posted 15 September 2005 - 11:28 PM

You can also get a Miller cycle engine in a Mazda Millenia, but I'm not sure of the years. It uses a supercharger though instead of a turbocharger (Miller cycle requires use of forced induction, and when the piston is coming back up with the intake valve still open, the pressure of the incoming air charge will press against the charge in the cylinder, so less air comes back out than one might expect. I suppose that with the use of a turbocharger, they probably use some sort of variable valve timing on the intake cam to advance the cam timing at idle and off boost, otherwise you'd lose quite a chunk of your charge.

There is a good article on Wikipedia and on howstuffworks.com on the Miller cycle.

#6 blitz

blitz

    Banned

  • Banned
  • 1,091 posts
  • Warren, Michigan

Posted 16 September 2005 - 10:51 AM

Yeah, "reversion discharge" isn't completely accuarate. Delaying the start of the actual compression until the piston has traversed part of the way up the "compression" stroke (by way of delaying intake valve closing) would be a better way of putting it.

Good point about the variable valve-timing. It'd be neccessary to close the intakes earlier at low rpm/ high-load conditions to preserve usable torque and turbo spool-up.

I think I originally learned of the miller cyle through Wikipedia. I had a difficult time understanding their description at first, but it's pretty simple once you see the big machine.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users