VJ-20 Hybrid turbo? IHI T-Bird comp side.

[smoke187]

if you took the cold side and center section and shove it into the VJ-11 exhaust housing you will still have a 15r lol

[heyoldguy2002]

sometimes a cigar is just a cigar

The t-bird turbo also uses the larger 20R turbine wheel and housing, just as the vj-11 (NOT so with the vj-20)...thats what makes it all so simple...no wheel swapping, FYI.

The 20R turbine has a greater a/r than the 15R...thus spool up onset will be later, but possibly more efficient at higher exhaust flows and less exhaust back pressure in the manifold and chambers...I'll avoid anymore bench racing here.

True, to use the t-bird hybrid with the vj-20, and its exhaust housing, then the vj-20 turbine wheel would have to be used...and thus one would still have the 15R housing, wheel, and resulting smaller a/r on the turbine side...if thats what y'all thought.

[smoke187]

say it is a 20r never had a vj11 why would you want turbo lag?

[heyoldguy2002]

Sorry to add any confusion...that has been my battle all along, and the reason why creating a hybrid has been frustrating to say the least.
Please refer to:

http://www.angelfire.com/extreme4/mattmouth182_rag/mx6/page.html

It explains the interchangability and numbering of IHI turbos. And should clarify your question.

I have only been refering to the hot side, and changing a/r of the housing, and resulting change of boost onset.

Don't get me wrong, I am not trying to engineer lag, but rather reduce backpressure in the manifold and exhaust ports...trying to have boost pressure actually exceed exhaust back pressure pre turbo (cross over). It really is a lame attempt at increasing/maintaining volumetric efficiency...but a pipe dream, or atleast reduce any negatives when messing with the efficiency of a n/a factory bp.

Most of the time the only variable ever mentioned is the a/r of the cold side, and resuling changes to boost efficiency. In fact, that is ultimately what we are all after, but I needed to understand the other side of the coin, so to speak.

I researched until I found a scenario where I could buy a new turbo and not actually remove either turbine or compressor wheels; simply move the center as a whole, but in this case I also wanted the slightly larger t-bird compressor too. All other discussions have had to swap wheels around. I actually wanted a VF-22 (Australia, NZ, JP, etc) it has a huge compressor and also the 20R exhaust side.

[FE3-323]

id be very interested to see a few graphs both flow & dyno comparing results between the 15r & 20R housings. .59 AR VS .787 AR for turbine housings is a decent change. effective boost, & powerband will change, just how much im not sure.

[dave0r]

my 2 cents worth

go with a VJ20/VF10 hybrid (cheap and works)
Not sure if you yanks got the VF8/12 setups in your subaru's they are worth that bit extra

the above hybrid is a small upgrade compared to other setups
TD05 T3,T4 VF22 setups

[heyoldguy2002]

DaveOr, you are very right. North America got left off the list for bigger turbos.And what you mentioned is spot on. I would have liked a new vf-22.

I only made the (minor) upgrade because I stumbled upon a new t-bird turbo and already had the modified vj-11.And other reasons already outlined.

Believe me when I say to everyone...I am not a huge advocate of this hybrid adventure. I only wanted something that would bolt on relatively easy to the BP turbo manifold (thanks Corksport), and upon realizing that a new vj-20 was super rare...researched alternatives.

Nuff said.

Go Canuks.

[Limegreen MX-3]

I Say Ditch The Ihi Turbo And Go Aftermarket

But Hey If Thats All U Can Do For Now

By All Means Go For It.

Good Luck On Finding The Rite Ihi Turbo Setup. For Ur Needs

[FE3-323]

IHI turbo's are wonderfully designed, however their range & compatibility isn't exactly all there for direct use on the BP. let alone how available they are.

[Lex]

The IHI VJ23 is probably one of the best turbo for the BP anywhere .... however really hard to find.

[dave0r]

nothing wrong with IHI turbos,

just stay away from the older non-water cooled models
and that rule goes with all turbo's