Notices
ScoobyNet General General Subaru Discussion

Single Scroll / Twin Scroll Turbos - Whats the Diff?

Thread Tools
 
Search this Thread
 
Old Sep 29, 2006 | 08:58 AM
  #1  
marmski's Avatar
marmski
Thread Starter
Scooby Regular
 
Joined: Jun 2006
Posts: 874
Likes: 0
Default Single Scroll / Twin Scroll Turbos - Whats the Diff?

Hi Guys,

I have done a search and cant really see any posts that answer my question.

I have a MY05 Blobeye STi Type UK which i understand being an EU variant will have a 'Single Scroll' turbo fitted, where as JDM imports have 'Twin Scroll' turbos. Whats the difference in reality? Would it be beneficial and is it possible to have a 'Twin Scroll' fitted to my Type UK?

Sorry to ask what could be a really simple question, but every other thread has something where someone mentions their 'Twin Scroll' and i would like to understand them a bit better.

Thnx in advance.

Ant
Reply
Old Sep 29, 2006 | 09:11 AM
  #2  
rasheedn's Avatar
rasheedn
Scooby Regular
 
Joined: Apr 2006
Posts: 182
Likes: 0
From: Kingston and Jerusalem
Default

and u say u've searched?????

a lot less lag
more power
Reply
Old Sep 29, 2006 | 09:14 AM
  #3  
Neilo's Avatar
Neilo
Scooby Regular
 
Joined: Jul 2003
Posts: 5,734
Likes: 0
From: Behind the wheel of a Time Attack R33 GTR
Default

you cant just fit a twin scroll turbo, you need a new manifold, downpipe, and oil sump.
Reply
Old Sep 29, 2006 | 09:56 AM
  #4  
MrRA's Avatar
MrRA
Scooby Regular
 
Joined: Sep 2006
Posts: 1,976
Likes: 0
Default

A "twin scroll" or "divided inlet" means that there are two separate volutes within the turbine housing. The main reason for doing this is to isolate the pulses coming from each exhaust port and maintain more of the pulse energy from each cylinder all the way down to the turbine wheel. There are no differences between the turbine wheels used in open or single inlet turbines compared to those used in twin or divided inlet turbines.
Generally speaking, a divided inlet turbine setup will respond faster and produce boost quicker than single or open design of the same nozzle area, of course this is dependent upon proper execution. The simple fact that a divided housing is used does not guarantee these results.

While it does not cause any problems or harm to run a divided inlet turbine housing on a manifold that is an "open" design, none of the benefits of the twin inlet will be seen.


Taken from the 'Forced Performance' Webiste FAQ
Reply
Old Sep 29, 2006 | 10:48 AM
  #5  
alex_00s's Avatar
alex_00s
Scooby Regular
iTrader: (18)
 
Joined: May 2006
Posts: 3,420
Likes: 2
From: Middx / Herts / Bucks / Essex
Default

Basically twin scroll turbos (as used in EVO's) spoll up much faster so alot less lag!
Reply
Old Sep 29, 2006 | 01:00 PM
  #6  
marmski's Avatar
marmski
Thread Starter
Scooby Regular
 
Joined: Jun 2006
Posts: 874
Likes: 0
Default

Sweet, tnx (to the people who actually posted useful replies.)
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
JimBowen
ICE
5
Jul 2, 2023 01:54 PM
WrxSti03
Drivetrain
11
Sep 29, 2015 10:21 AM
madmover
Member's Gallery
4
Sep 28, 2015 10:46 AM
Phil3822
ICE
3
Sep 26, 2015 07:12 PM




All times are GMT +1. The time now is 09:11 AM.