scoobyclinics turbo's just got billet I mean better! - Page 9

**The Gaffer** · 18 February 2010, 10:08

Hi,

printout as promised

It clearly shows improvements all round but still not satisfied with spool

Time to address pipe work and run the test again

Results to follow good or bad

Cheers
Kev

**The Gaffer** · 18 February 2010, 17:33

Hi,
on another note the SC46 billets will be here this week

at last !

Look at what is coming with them

An SC46 Twin Scroll Billet

Cheers
Kev

TimH · 18 February 2010, 18:58

Quote:

Originally Posted by The Gaffer

Look at what is coming with them

An SC46 Twin Scroll Billet

Groan...and here I am still waiting to get the results from my LM480 from Iain Litchfield (waiting on massive, unrelated, oil leak being sorted, on top of the cracked downpipe, before I know what it produces) and you go and post about another choice I could have been tempted by

wrx9181 · 19 February 2010, 17:04

what engine is that suited to kev? and what power .... with supported modz of coarse...
and is the twin scroll just for jdm models?

**RA Dunk** · 19 February 2010, 18:39

Quote:

Originally Posted by The Gaffer

Hi,
on another note the SC46 billets will be here this week

at last !

Look at what is coming with them

An SC46 Twin Scroll Billet

Cheers
Kev

Looks good, what car/engine will you be testing it on? you dont have any 2.1 strokers lying around you want to test it on do you?

**The Gaffer** · 20 February 2010, 10:30

Quote:

Originally Posted by wrx9181

what engine is that suited to kev? and what power .... with supported modz of coarse...
and is the twin scroll just for jdm models?

Hi,

It is a direct replacement for JDM cars, however it can be retro fitted to any scoob with the relavent headers, up pipe and sump etc.

The Hawkeye cars are all fitted with the correct sump as standard so retro fitting a twin scroll would be straight forward.

Power wise we will have to wait and see, running the test Friday

cheers
Kev

wrx9181 · 20 February 2010, 11:26

Thanks sorry for silly questions but if you dont ask you dont learn cheers

wrx9181 · 20 February 2010, 11:34

sorry kev another question here ..... So whats advantage of twin scroll over other sc46?

**The Gaffer** · 20 February 2010, 12:31

Quote:

Originally Posted by wrx9181

sorry kev another question here ..... So whats advantage of twin scroll over other sc46?

Hi,
we will wait to see what advantages if any

It is really aimed at the JDM cars where so far there are not many turbo up grades available.

cheers
Kev

wrx9181 · 20 February 2010, 16:18

ah right thought it was faster spool or something

joz8968 · 20 February 2010, 17:19

The twin scroll separates the exhaust gas feed into two smaller venturi, than the regular 'single-scroll'. I assume this speeds up the gasses so as to aid spool up, as you say. This is the reason why there are not many twin-scroll turbos, as it's relatively new to the Impreza. Plus there are a lot of well-estb and effective normal turbos/uppipes/dowpipes, which don't help the aftermarket twin-scroll cause...

wrx9181 · 20 February 2010, 22:19

cheers joz

wrx9181 · 21 February 2010, 13:31

Might be interested in the twin scroll as things are changing .... let me know how it goes

joz8968 · 21 February 2010, 14:11

Do twin scroll headers have a different pattern uppipe-mounting flange too? Or can a TS uppipe fit onto normal headers and also be in the correct postion to bolt onto the TS turbo?

**The Gaffer** · 21 February 2010, 14:52

Quote:

Originally Posted by joz8968

Do twin scroll headers have a different pattern uppipe-mounting flange too? Or can a TS uppipe fit onto normal headers and also be in the correct postion to bolt onto the TS turbo?

Hi,

its a different footprint on both up and down pipes which is why retro fitting the twin scroll can get expensive.

We are going to back to back the twin scroll against its single scroll brother and see if its worth forging ahead with it, (excuse the pun)

We will still be able to offer the twin scroll Billet turbo to JDM owners as an upgrade but it may not be economical for a single scroll to twin scroll conversion, unless of course the gains warrant it

Cheers
Kev

joz8968 · 21 February 2010, 16:15

Sorry, it was a daft question - the uppipe obviously has the twin venturis, so its header flange - and headers - MUST be different.

**Jolly Green Monster** · 21 February 2010, 21:12

Quote:

Originally Posted by joz8968

Sorry, it was a daft question - the uppipe obviously has the twin venturis, so its header flange - and headers - MUST be different.

the header design is entirely different.. the sump is different to clear the headers..

cylinders are paired and kept separate right to the turbo rather than mixing at the collector.

Simon

TimH · 21 February 2010, 22:00

A true twin-scroll has a different exhaust turbine to a single scroll: there's a set of blades designed to be spun from one of the pair's of header pipes, for low rpm performance; and a second set for higher rpm.

The separated pipe-pairs from the heads mean exhaust scavanging is better, and the turbine design means spool is greatly improved, but at the expense of high-end power since not all the exhaust gases are spinning the turbine at high rpm.

Most high power "twin-scrolls" are actually "twin-entry": the exhaust scavanging properties are maintained, as the separation of the header pipe pairs is maintained right up to the turbo housing, but the impeller is a standard single-scroll core. A bit of a compromise really.

So, the proof will be in the spool characteristics vs top end power.

All IMHO of course

typeRv4 · 21 February 2010, 22:15

Question is the vf36/37 true twin scrolls ?

TimH · 21 February 2010, 22:17

Quote:

Originally Posted by typeRv4

Question is the vf36/37 true twin scrolls ?

Yes

joz8968 · 21 February 2010, 23:15

Cheers for the explantion. It's nice that those turbo's are true ones.

Is the Toyata twin-entry turbo on the Mk.2 MR2 a normal single-scroll impeller-equipped one, out of interest?

**RJMS** · 21 February 2010, 23:24

Quote:

Originally Posted by tim hardisty

The separated pipe-pairs from the heads mean exhaust scavanging is better, and the turbine design means spool is greatly improved, but at the expense of high-end power since not all the exhaust gases are spinning the turbine at high rpm.

I'm confused by this, mine is a Miltek & Sports Catted otherwise standard MY 03 JDM Sti, peak torque is at 3800, but power hits 320 at 5750 ish and then stays above 320 right the way through to 7500+ actually peaking at 330 at 6500. It certainly doesn't seem to lack top end power but the torque does fall away fairly rapidly as the revs rise.

**The Gaffer** · 23 February 2010, 15:09

Hi,

at last the SC46 billet direct fit turbo's are here

Just need to find a test mule now

Keep you posted.

cheers
Kev

**Granby** · 23 February 2010, 15:39

Very nice

joz8968 · 23 February 2010, 15:43

I'll watch the SC46 tests with interest (as my engine would be at its limits if one was fitted).

I'll be interested to see how much it pi$$es over the 20g! and how it compares to the 321...

wrx9181 · 23 February 2010, 20:10

what do you need to test it on kev? 2....2.1...2.35....2.5?

Mad Hammer · 23 February 2010, 20:40

Quote:

Originally Posted by joz8968

Cheers for the explantion. It's nice that those turbo's are true ones.

Is the Toyata twin-entry turbo on the Mk.2 MR2 a normal single-scroll impeller-equipped one, out of interest?

Single scroll with twin entry same as my GT4

joz8968 · 23 February 2010, 20:47

Quote:

Originally Posted by Mad Hammer

Single scroll with twin entry same as my GT4

Thought so.

Does the MR2 turbo have exactly the same engine/turbo as your GT4 ST205?

Mad Hammer · 23 February 2010, 20:50

Quote:

Originally Posted by joz8968

Thought so.

Does the MR2 turbo have exactly the same engine/turbo as your GT4 ST205?

Only the Rev 3 onwards has same turbo

joz8968 · 23 February 2010, 20:57

Sure. Love the Rev.3 MR2 in gleaming black (in a kind of cheesy, hirsuit, hairy-chested kindaway

). But would get scared peddling it with any viguor!

As Performance Car said of the Rev.1 MR2 Turbo 225: "The N/A (158bhp GT) version is fast enough thank you very much!"

It's the one rare example of a car where an aftermarket bodykit actually enhances its looks! (Toms)

Sorry, I'm going waaaaaaaaay off topic here.