Welcome to the North American Subaru Impreza Owners Club Monday July 6, 2015
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 03-01-2001, 01:28 PM   #1
ninetalesnwf
Scooby Newbie
 
Member#: 3739
Join Date: Jan 2001
Location: Auckland, New Zealand
Vehicle:
85 R30 skylineGT-T
Red/black

Post Why twin Turbos?

what is the benifit for twin turbos, it it less turbo lag at high boost or are you able to get higher HP

thanks
* Registered users of the site do not see these ads.
ninetalesnwf is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 03-01-2001, 01:43 PM   #2
DigDug
Scooby Newbie
 
Member#: 4077
Join Date: Feb 2001
Location: Eastern US
Vehicle:
1999 Impreza 2.5RS
Aspen White

Talking

One usually has a smaller turbine, which lets it spool up faster, and when it gets out of its powerband, the second one is generally already spun up and is getting into its powerband. I doubt there is more HP to be had, the smaller one will become a restriction eventually, if you go that high with boost...
DigDug is offline   Reply With Quote
Old 03-01-2001, 01:44 PM   #3
DigDug
Scooby Newbie
 
Member#: 4077
Join Date: Feb 2001
Location: Eastern US
Vehicle:
1999 Impreza 2.5RS
Aspen White

Talking

Oh, and let me clarify that I am talking about a sequential turbo setup, not running them in parallel. I have personally never seen multiple turbos being run in parallel, but who knows? Somebody's probably tried it...
DigDug is offline   Reply With Quote
Old 03-01-2001, 01:51 PM   #4
svxtrem
Scooby Newbie
 
Member#: 1008
Join Date: Mar 2000
Location: Grand Forks, ND
Vehicle:
2006 STI
Steel Grey Metallic

Post

There have been many examples of small turbos used in parallel (VR-4, 300ZX)- the benefit is that two smaller turbos will spool more quickly than a single large one. Sequential turbos 'should' have the best of both worlds, even faster spool up, with no power loss on top end. If the turbos are sized correctly, there isn't much advantage of a single turbo over two turbos, unless you can arrange things into an even-firing 3 cylinder design. In this case, you can create an extremely efficient pulse design (depending on camshaft overlap) to drive the turbine.
svxtrem is offline   Reply With Quote
Old 03-01-2001, 01:55 PM   #5
DigDug
Scooby Newbie
 
Member#: 4077
Join Date: Feb 2001
Location: Eastern US
Vehicle:
1999 Impreza 2.5RS
Aspen White

Lightbulb

Hmmm, I always thought the 300ZX was a sequential turbo setup....
DigDug is offline   Reply With Quote
Old 03-01-2001, 01:59 PM   #6
mrbell
Scooby Specialist
 
Member#: 1871
Join Date: Jul 2000
Location: Salt Lake City, UT
Vehicle:
2000 Impreza 2.5RS
Blue Ridge Pearl

Post

actually... most dual turbo setups are parallel... I believe, the supra twin turbo (maybe, I've heard it is and heard it isn't) and the RX-7 were the only sequential setups that were somewhat widely available. you get two small turbos to spin up faster, so you get less lag, and at higher rpm, you have two turbos, so you should be able to get good boost, even tho they are, on their own, out of their range...
the only benefit I can see of single turbo setups over duals, is simplicity, which can add other benefits as well(lighter, less parasitic loss, etc)
mrbell is offline   Reply With Quote
Old 03-01-2001, 02:03 PM   #7
pbnj9786
Scooby Specialist
 
Member#: 4473
Join Date: Feb 2001
Location: CA, USA
Vehicle:
MY10 STi
Plasma Blue Pearl

Post

Porsche uses the sequential setup as well, and as everyone here knows, Subaru shares the same engine design with Porsche. Personally i wouldnt mind seeing a Legacy twin turbo. or better yet a wrx twin turbo.
pbnj9786 is offline   Reply With Quote
Old 03-01-2001, 02:09 PM   #8
DigDug
Scooby Newbie
 
Member#: 4077
Join Date: Feb 2001
Location: Eastern US
Vehicle:
1999 Impreza 2.5RS
Aspen White

Talking

There is a twin-turbo Legacy in Japan, and it is a sequential setup. I was actually looking into importing one and dropping it in my 2.5RS about a year ago. Freight charges alone were scary...

Though Porsche and Subaru both use boxer engines, I do believe the Porsche engines are a little better engineered!
DigDug is offline   Reply With Quote
Old 03-01-2001, 02:20 PM   #9
blaster88
Scooby Specialist
 
Member#: 1109
Join Date: Mar 2000
Chapter/Region: MAIC
Location: Reston, VA
Vehicle:
1999 Suzuki Samurai
Blackish

Post

Bigger question: why NOT twin turbos?
blaster88 is offline   Reply With Quote
Old 03-01-2001, 02:25 PM   #10
pbnj9786
Scooby Specialist
 
Member#: 4473
Join Date: Feb 2001
Location: CA, USA
Vehicle:
MY10 STi
Plasma Blue Pearl

Post

Well, in the imprezas, i dont think there is room for and the necessary header tubing and the turbos of course.
pbnj9786 is offline   Reply With Quote
Old 03-01-2001, 02:45 PM   #11
iodine23
Scooby Specialist
 
Member#: 4071
Join Date: Feb 2001
Location: Austin, TX
Vehicle:
2001 Impreza 2.5RS
Blue Ridge Pearl

Post

blaster88: Why not parallel or why not sequential twin turbos?


I would think the main reason for parallel twin turbos is so you can drive one turbo from each side of a "V" engine. Seems like a pretty convenient setup.

If you were to parallel twin turbo an inline engine, it probably gets more complicated to route separate headers down for each turbo.

So then why not twin parallel turbos in the Impreza, right?

One reason I could think of is that if you have a turbo for each pair of cylinders, then each turbo is only getting power half the time since the engine is a four stroke. So you have two half-powered turbos now, and you're probably not netting any gain.
iodine23 is offline   Reply With Quote
Old 03-01-2001, 02:46 PM   #12
jeffg
Scooby Guru
 
Member#: 2958
Join Date: Nov 2000
Chapter/Region: NWIC
Vehicle:
2001 WRX (GC8)

Post

I noticed that the SYMS catelog has a header setup for twin turbo in a legacy. It looked really nice.
jeffg is offline   Reply With Quote
Old 03-01-2001, 07:25 PM   #13
mrbell
Scooby Specialist
 
Member#: 1871
Join Date: Jul 2000
Location: Salt Lake City, UT
Vehicle:
2000 Impreza 2.5RS
Blue Ridge Pearl

Post

yeah, I forgot to mention the porsche, but I didn't know there was a sequential legacy... interesting...
mrbell is offline   Reply With Quote
Old 03-01-2001, 10:16 PM   #14
brendon
Scooby Newbie
 
Member#: 3618
Join Date: Jan 2001
Location: billings,mt
Post

if you are looking for minimal lag and much boost get the aerocharger. they are about 2300$ for the one that fits ej25. what a slick set up no waste gate but variable vane settings hmmmmmm. smooth
brendon is offline   Reply With Quote
Old 03-01-2001, 10:34 PM   #15
Hucker
Scooby Specialist
 
Member#: 1272
Join Date: Apr 2000
Location: Hamilton, Ontario, Canada
Post

Those areochargers are used alot on Harley's etc. Watched a show on Speedvision about them....
Hucker is offline   Reply With Quote
Old 03-01-2001, 11:17 PM   #16
Adrian128
Scooby Specialist
 
Member#: 3346
Join Date: Dec 2000
Location: Sydney,Australia
Post

The Legacy twin turbo is a sequential set up, and the EJ20T from an Legacy has been put in a RHD WRX, with mixed results.
Also.. there are a few inline engines with parallel turbo set ups.. Nissan RB26DETT for one, and the Supra TT engines both have twin turbo set ups.
Adrian128 is offline   Reply With Quote
Old 03-02-2001, 01:03 AM   #17
MikeYOX
Scooby Specialist
 
Member#: 1754
Join Date: Jun 2000
Location: West Boemfugk, Egypt
Vehicle:
2002 S4
Nogaro Blue

Post

Quote:
Porsche uses the sequential setup as well, and as everyone here knows, Subaru shares the same engine design with Porsche. Personally i wouldnt mind seeing a Legacy twin turbo. or better yet a wrx twin turbo.
Actually Porsche uses twin identical turbochargers that operate parallel eachother.
MikeYOX is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS/FT 1997 VR4 Vacuum Leak $6,500 Twin Turbo Twin Intercooler Meat9834 Private Vehicle 'For Sale' Classifieds 14 01-04-2010 05:49 PM
Twin Turbo and Twin Supercharged Nissan GT-R bend_bugeye Non-Subaru News & Rumors 14 10-15-2009 07:36 PM
Twin Engine, Twin Turbo, 626WHP, 1997 Tiburon, 10.92 1/4 mile on STREET tires alien_sporez Private Vehicle 'For Sale' Classifieds 3 05-04-2008 12:49 AM
What company's offer twin scroll twin turbo kits for the sti? GT42r Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 32 09-12-2007 10:27 AM
Will the twin turbo EJ20 fit 91-94 Legacy turbo? jwooman Legacy Forum 5 05-02-2001 12:26 AM


All times are GMT -4. The time now is 09:02 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2015 Axivo Inc.
Copyright ©1999 - 2015, North American Subaru Impreza Owners Club, Inc.