has anyone done a twin turbo conversion?it looks as though it would be a really good conversion as the flat4 engine is pretty much two seperate engines with a shared crank anyway.i know it would add weight and **** would probably be a bit tight but im sure it would work pretty well

 

A quick search on google revealed one of these...



...twin turbos, fitted by Subaru, on the production line

 

standard legacy lump.

 

ok maybe i should have put anyone twin turbo'd an imprezza

 

I have a Leggy GT-B Spec which is 290BHP with a manual box.

The power delivery is quite a bit different to a Impreza's, being the twin turbo, there's a pause between the primary and secondary turbo spooling up, ( known as the VOD - valley of death ) When on the secondary turbo, they are a very very quick machine ( faster than a new STi in 4th and 5th gears on boost )

They are not to everyones taste, as the turbo doesnt come on boost as quick as its baby brother.

Fuel economy is better on the twins than the Impreza's, I get 25mpg knocking about town, and 30 on the motorway.

The answer to your original question - has anyone ever done the conversion, its quite possible, but I cant think of any reason why any Impreza owner would want to transplant to a twin.

Impreza's are street machines, and Leggys are cruisers.

R7

 

her it is done on a bug eye... your welcome its a beauty to looK at.....

All Aspects TT WRX

steve

 

rapidseven-i meant run as two seperate turbo curcuits i.e. one turbo system for each bank of cylinders rather than a sequential turbo set up running both banks together

the twin turbo bug eye in that link looks like they have gone the complicated way about it

 

thats true...but it looks awesome through the front bumper though

 

CLICKY

DETAILS

 

The downfall of two separate turbo circuits is you'd need a pair of itty bitty turbos to get good driveability. As you only have 2 cylinders, of 1 litre of capacity to spin them. Otherwise it would be too laggy and give no benefit over a single turbo. Unless the engine capacity is increased to compensate (i.e 2.5 block).

Twin scroll is a good compromise as it combats the problem with uneven exhaust gas pulses (like a twin setup) by seperating them into two exhaust scrolls. So a larger TS turbo will respond like a smaller non TS one, but will have the extra flow capacity to maintain high boost at high revs.

 

That WRX is a master piece, outstanding engineering.

Is there any footage of it running anywhere, would love to hear the gurgle of the Subaru, the turbos and especially the blower, all working hard, and all at the same time !

Brilliant.

R7

 

well skylines seem to get by ok with 1.3l per turbo
its not something im asking about with a goal to doing it,was just wondering