Converting to JDM Twin scroll question

Hello,

Im in the process of piecing together a twin scroll setup for my legacy gt. I already have my hands on the JDM OEM TS manifold & up pipe, I have a USDM downpipe to hack up and add the TS flange.

Now my question is regarding the turbo and my AVO TMIC. I know Kinugawa sells a 19t and 20t bolton option. But is it also possible to swap the compressor housing off of a vf37 for the VF40 so that i can retain my AVO TMIC?

Eventually I would like to get a td05 18g twin scroll setup with the TMIC... that should spool nice and fast and have plenty of top end.

I still need fuel mods so i dont want to go to big right now which is why im considering the vf37 over a new turbo.

A lot of IHI turbo's can utilize each others compressor and turbine housings. the differences being the shafts and bearing designs (as well as compressors and turbines). vf22 and vf34's can use a vf36's TS turbine housing (most ball bearing IHI turbos have identical CHRAs). alternatively, a VF52 compressor housing fits on a VF37 (most journal bearing IHI turbos have identical CHRAs). once you move to aftermarket compressor wheels, there's machining involved to mate the compressor housing.

watch out for which TS turbine housing you get too, as they require different DP flanges. 19t turbo's are different than vf36/37's.

the P18 is also smaller than the P25, so for more top end/flow, go for the P25.

Also, depending on the turbine and compressor housings, you'll need different coolant and oil hoses, as well as turbo stay brackets. oh, and wastegate actuator.

there's a lot of little details to get right for a swap like this.

from what I know though, the VF40/VF46 compressor housing will not mate up with JDM TS turbo CHRA's.

A lot of IHI turbo's can utilize each others compressor and turbine housings. the differences being the shafts and bearing designs (as well as compressors and turbines). vf22 and vf34's can use a vf36's TS turbine housing. alternatively, a VF52 compressor housing fits on a VF36. not positive on how the VF37 fits into the interchangeability of compressor and turbine housings. once you move to aftermarket compressor wheels, there's machining involved to mate the compressor housing.

 

watch out for which TS turbine housing you get too, as they require different DP flanges. 19t turbo's are different than vf36/37's.

 

the P18 is also smaller than the P25, so for more top end/flow, go for the P25.

 

Also, depending on the turbine and compressor housings, you'll need different coolant and oil hoses, as well as turbo stay brackets. oh, and wastegate actuator.

 

there's a lot of little details to get right for a swap like this.

 

from what I know though, the VF40/vf46 compressor housing will not mate up with JDM TS turbo CHRA's.

Thank you for this information. I really want to keep my AVO TMIC if all possible. Im leaning towards the 20t for now unless i can source a vf37 & VF52 compressor housing.

so I just looked at the 19t and 20t at kinugawa, those are the "other" version of twinscroll turbo's for the JDM Subaru's (unique TMIC and DP connection). you'd need a JDM OEM TMIC to mate with that compressor housing.

for the money, and thinking I know what you already have, your best bet might be to go with these:

http://6starspeed.com/twsc08wrx05l.html

although if you can get a good deal on a VF52, then do that and get this:

http://shopping.kinugawaturbo.com/kinugawasubarutwinscrollturbinehousingkitconvertihivf22vf34tovf36.aspx

Or if you can get a VF37, then just scrounge up a VF52 compressor cover.

ha, or get one of these in VF52 trim, buy the Kinugawa TS turbine housing kit I linked above, and scrounge a VF52 compressor cover...

http://6starspeed.com/rhhipech.html

depending on the price of the VF52 cover, you could have yourself a "new" TS turbo for 390+275+?= $665

I shoulda done this myself. short of all the extra parts to switch over to TS, this is a pretty cheap option for a lot of quick power.

You sir are the man!

your post has given me several options now.

A few more options.

Pick up a twin scroll STI 18g & swap the compressor housing with a wrx/lgt 18g compressor housing.

or even getting a vf52 and swap the exhaust housing to the TS kit you linked.

I'm chiming in late I know, but another option if you can make the time; is to get a hold of a GRB (2009-2014) STi TMIC/y-pipe and inlet manifold.

You can then mate with any STi twin scroll as long as you have the JDM STi TS headers and up pipe.

This is what I have done on my 2004 ADM LGT (VF38 twin scroll as standard). I am running a VF49 twin scroll from a 2013 GVF JDM Sti.

For the money (I was able to get headers, up pipe, turbo, TMIC, inlet manifold and the JDM down pipe which is bell mouthed from factory), I think this is a fantastic conversion!

Buuuuut, if you have the JDM LGT twin scroll headers and up pipe (which are also on the 2004-2006 Liberty GT released in Australia too, btw), then the Kinugawa 20T turbo with a VF52 compressor housing will be similarly awesome.

The VF49 is largest of any VF turbo released from the Subaru factories to date (It's the same size as the BB VF53 and BB plus titanium comp wheel VF56) and on my 2.0L engine I see 20 psi at 3,400 and at redline (7,200) it's dropped to 16psi. I have the 5EAT. the 20T performs very closely to this I'm told

Mine has the TD04HLA-19t as standard for the manual version in Japan.

It is pretty much optimised for flow now according to the mapper Andrew Carr - he was able to push it a little more due to me having to swap out the short engine for a STi8 unit, but we retained the quad AVCS to optimise the timing. The solid red line is the latest flywheel power and torque with the STi8 build...

http://img.photobucket.com/albums/v704/hoojamyflip/Legacy%20Twinscroll/SilverLegacydynocomparison_zpsb701d873.jpg

HTH

Without the heads, those power figures are going to be difficult to achieve.

Testing done here in Aus with the ADM heads (identical the the 04-06 JDM ones) is that they outflow even the latest EJ257 heads.

That's some serious power you're achieving there Mick (is it Mick??? says so on the dyno plot lol ) Awesome

Helps with a question asked recently here is Aus; what power can you get out of the 19T TD04HLA (not the stock ADM turbo; we got smaller comp and turbine wheels, but still slightly bigger than the VF38s)

Sorry i'm so late to the thread as this is my first post in years. I am running the VF52 (08+ WRX) compressor cover on a VF36 TS on my 06 LGT which I did years ago. (Still going strong at 20PSI) As was already said, the 52 comp cover fits on the VF 36/37 TS turbos (And on the VF30/34 SS) for LGT/WRX TMIC fitment. (With the proper up/downpipe and manifold)

Also when I was playing mix and match, I remember the VF37 turbine housing fitting on the VF52 and 34 CHRA. (If you want to make a JB or BB TS turbo) I had a bunch of these turbos on the bench to see all the IHI hybrids that could be made when preparing for the build. There is something different on the VF36 turbine housing but I cant remember what. (As well as the turbine itself being an exotic alloy)

With all the cheaper aftermarket options out there now, probably better off going that route if you haven't already.

I hope everyone is well and best of luck with the project!