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

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

a lot less lag
more power

you cant just fit a twin scroll turbo, you need a new manifold, downpipe, and oil sump.

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

Basically twin scroll turbos (as used in EVO's) spoll up much faster so alot less lag! :luxhello:

Sweet, tnx (to the people who actually posted useful replies.)