DAZ

hi lads has any modified to a twin turbo
system if so what where the results

i was thinking of a sequential turbo system
similar to supra seems a nice concept

how pratical is it

cheers daz

Mike Tuckwood

Daz.

Have you been smoking those dodgy **** again?

MorayMackenzie

I think the 22B is supposed to have an old 2.2 legacy block. Subaru didn't use the twin turbos or charge cooling though.

Moray

AlexM

I'd be suprised if you could fit another turbo and its associated manifolding inside the impreza engine compartment. Seems a pretty tight fit as it is.

Cooling may become an issue as well.

Benny Boy

Daz

There were a couple of properly tuned WRXs in Australia with twin turbos.

Both the cars are now back to a single turbo as they could not get the power delivery sorted well enough.

Kind regards

Ben

DAZ

cheers lads it was just a thought

bit of a project through the winter months

maybe a rethink

benny have you got any more info on those in oz
id like to read up on it

cheers daz

EvoTim

Why don't you go with a single turbo and supercharger install a la Delta S4 Grp B rallycar?

Branners

you wouldnt want to know the complexity involved in getting the twin turbos to run sequentially. We have 4 VSVs (solenoids) which are computer controlled to open at specific points to bring the turbos on line at the right time. Tied into this we have large oil coolers to try and do something with the heat and fairly big intercoolers to try and get the charge temp down.

The import Supras have the first turbo come in at about 1,500rpm, and then at 3,500rpm a solenoid opens to pre-spool the 2nd turbo, which finally comes in at 4000rpm and both turbos then run all the way up to red line. The ECU monitors the boost to ensure fuel cut is maintained at about 15psi, and the highest a stock Supra would reach is 11psi on both turbos or 7psi on the first one.

Im sure we have in-depth info on how it all works somewhere if you are considering it. Oh and both turbos are the same size.

John Branigan

firefox

Daz..

what exactly were you thinking ?

Sequential or a twin config ?

The new Legacy is twin turboed...

There are a couple of problems with twin turbos... location/space...flow rate....and heat

Like I have always said.. depends what you are after...?? if its top end.... fit a large single turbo (like the skyline, RX7, Supra conversions, which change from two turbos to a single huge one).

If its bottom end.. you should consider two smaller turbos..... but fitting two VF-28 (what you have on your car) wont double the flow rate... it doesnt work like that...

You would then have to look at uprating the flow of the I/C...

Like Branners said.. sequential is very hard to set up... I too have seen the Oz articles on twin turboed cars... and the engines took ages to be set up..and were built and adjusted on an engine dyno.. not in a car on a RR..

The super charge and turbo setup is similar to sequential.. the super charger cuts in first... running low'ish boost... then once the revs are up.. the system changes over to the turbo...and delivers the top end...

J.

Branners

if you are having problems with lag then you might want to use nitrous. It can be set up to give maybe a 75bhp push and as soon as the turbo cuts in it turns itself off. Almost all the lag will be removed and so long as you dont go mad with the size of the nitrous injectors it should be safe enough.

I havent seen anybody on this list mention nitrous so I dont know if its really an option, but its still a thought.

John Branigan

firefox

Hi branners...

I have considered and looked into Nitrous... using a 50 shot wet system.. with controller that is linked to revs... this was to eliminate lag...

I have never actually tried it yet... the hassle of having to refill everso often puts me off... as do the safety aspects...

Who knows.. If I'm not happy with my lag.. then maybe I might give it a "shot".. get it ? haha *god I'm so funny*

J.