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yeehaa! finally got myself one of these to put on the EJ20T in my kombi.

check it out in the guide to VF turbos above courtesy of 72WRX...seemed to me to be the best option considering the weight of a kombi...

There will be a bit of modifying to fit it...different flanges and even changes to my manifold with the twin intake....

I can easily change my my manifold to twin outlet but my question is which cylinders should i pair together or does it matter?

nice size.....do ur self a favour pm Seagull he will help u on that question

yeah waiting for Neil to wake up

so what rpm does the boost come on ???

^^ WHAT HE SAID! im also curious if they are worth the crazy price tag & hype on forums etc

I am awake , From factory the sump is modified & the dip stick is different. This is a good photo to see the pipes , if they go for this $ its not worth making them

http://cgi.ebay.com.au/Extractors-Twin-Scroll-Suit-Subaru-WRX-STI-EJ20-25_W0Q...

Geez Neil why didn't i find that! it tell me exactly what i want to know

plenty of info around about these...found this on a suzuki vitara:

Well, I may as well join the fun. here's my little joy'n pride.

EMS = Split second fuel controler. MSD BTM - 1/2 deg retard per pound of boost with base timing set @ 12 deg for maximum fuel efficiency and power pick up.
Engine = Rebuilt block, Vitara pistons, stock rods, heavily ported head, studs & kisses everywhere.
Injectors = Supra 460cc
Boost = 13.5psi
WHP = First dyno run showed up 187.3whp @ 8 psi. My guestimate would be in the surrounding of 205-210whp @ 13.5psi
Fuel = 92octane
Charger = IHI VF38
On Boost = Boost threshold at 1650rpm, 10psi at 2400rpm, 15 psi @ 2700
Manifold = Special design for twin scroll purpose. Hi-performance twin port downpipe. Ceramic coating all around (manifold, downpipe & turbine housing)
Anything else = Lots, too much to be numbered actually.


As you can see, the IHI turbo is the shit. Without a doubt the best turbocharger I ever seen/tested in my life (for that application to the least). It's a very expensive JDM subaru turbocharger. A tad larger than the stock STI JDM turbo. It can support 250whp @ 22psi. It's a large, still extremely fast spooling turbocharger that would put any supercharger to shame. You get 5PSi anythime you step on the pedal between 1800-2000rpm, making and insane amount of torque very soon on the powerband. I suppose having 15PSI from 2700rpm all the way to the redline pretty much tell the tale. What make this turbo so good is that it's a twin scroll turbocharger with two separate ports running around the turbine housing. The turbine wheel & shaft are made out of titanium alloy, which is very light, IHI's finest. To give you an idea, a standard turbo if its size, says a Garrett GT2871R, would be getting full boost no sooner than 4800-5000 rpm. The ceramic coating also play a big part, keeping as much heat as possible inside the runners/turbine to help spool the turbo as fast as possible. Lesser energy losses = better efficiency.

That info is not correct. A VF38 is from a 2l Legacy and is about the size of a TDO4 that is fitted to most garden variety WRX's. It's a good size for an EJ20 but is nothing special. It is light years away from a 2871 in size. The twin scroll housing helps to bring it on boost faster but so does the QUAD Variable valve timing that the Gen 4 legacy engine has so the jury is out on which is the better setup.

The headers posted are for a VF36 or VF37. These are the STi turbos which are basically twin scroll versions of the std Aus delivered STi turbos. They appear to be the same as the VF38 but are infact completely different flanges and pipe sizes.

Cylinder pairing for an Ej engine is front 2 and rear 2. This also removes the "boxer burble" that WRX's are known for.

thanks for that...i was not looking for a big turbo but only one that would bring the torque on early and this seems to fit the bill

No doubt that it will be the on the torquey side but the twinscroll creates it's own set of issues.
A few years ago I bought a VF37 STi turbo which was new at the time. The exhaust manifold was more expensive than the turbo so I decided to adapt my own. I bought an ebay manifold that matched the right cylinders to make the TS work properly and built the rest of the car around it. It worked ok but I don't think it was any batter than a std non twin scroll setup. This was with a 97 STi engine. My take on it is that the twinscroll is part of a package with the avcs variable valve timing technology in the later engines.

If you like making pipes then go for it.
But old mates suzuki blurb was obviously crack fuelled as it is not accurate.

Here's my VF37 custom install.







Yes it will work but I think you would be better with a TDO4L that bolts up and sell that to a Liberty GT owner that needs a new turbo. They are quite prone to failure which is very unusual for IHI stuff.

yeah i do like pipework...was a boilermaker in a previous life and the turbo, like my whole kombi is a useful hobby. I take it bush and am looking for lowdown power and torque.

I have a TD04 and at highway speeds the kombi is a weapon...as far as kombis go but i want grunt to get me up a mountain...i'll give this a go and if not happy will try something else...it's all good fun...thanks for the advice

Making pipes is a good enough reason to do it.

The twin scroll sumps are very common now anyway as most of the o5 on engines have them, NA or turbo. You can also easily adapt a set of NA 05- headers to a turbo application. I've got some that I would will sell for $75.

Edit - none will help if you need a shortened sump.

al, i think i need to pick your brains about my turbo choice think ill be visiting once its running

more bullsh and lies about VF38s

." It's a ball bearing turbo made out of featherweight titanium, not iconel. The turbine is very light plus the twin scroll design decrease spool up times even more. It's very unusual, not to say shocking to see such a large turbo to spool so fast. At 2000 rpm you get 5psi. At 2300 you have 10 psi. At 2650rpm you have 15 psi of pure fury. Yes, you've read well, hand on my heart, I can tell you this turbo pulls 15 PSI @ 2650rpm. It spools so fast that it could actually be used in a G10 turbo setup and still have a decent threshold of 2000rpm. I wonder why people bother to install stupid supercharger setups (sorry vloewidjl) when there is such good turbos available. The torque you get with 15 psi @ less than 3000 rpm is just insane."

"trust no one...the truth is out there"..mulder

Wow, that's a steaming load. I have one at work, it's a plain bearing turbo with normal everything, nothing special apart from the twin scroll housing.

It seems that people are quoting stuff they have read about the VF36 turbo which has all those features. it's also a limitied edition thing only available on RA versions of JDM STi's. It's basically a VF34 with a titanium alloy turbine and TS housing. The STi VF turbos are much larger than a VF38. Still not particularly big though, just perfect size for a performance road car 2.0l engine.(think garrett GT2860)

The IHI turbo info blurbs that are on every subaru related forum(including this one) are almost completely fabricated by someone who cannot possibly have ever seen the turbos. They are almost completely innacurate.
I can redo it if anyone is interested. I have measured and photographed nearly all of them.

well my VF38 turbo arrived today

i've been waiting so i can start on the various drawings for flanges and pipe sizes...

it's very interesting...the twin inlets are 36mm each which gives a total area of 20 sq cm compared to the single inlet on the TD04 of 44mm which gives an area of 15.2 sq cm which i assume means more flow and more evenly

this time i'll actually go and buy some 36 ID pipe to build the headers...i think my previous ones at 42 ID were too big and didn't help spooling up

anyway plans are drawn...lots of welding i'll have to build a strongback to weld it on to minimise distortion...oh and there'll be no modifying sump or dipstick

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Saving some $ Rob , no need to change the sump. Are you going to make the above out of water pipe again ?


Al would a mitsubishi tdo5 16 g work in this application seeing the headers are now going to be fully fabricated. There is a few basicly new 500ks turbos here in perth going for $150.00. There does not seem to be any other application for them.

Do you mean reverse rotation turbos off Evo's? You could use any turbo in the front(rear?) mounted application I guess. Some of the Evo TDO5HR's are very good turbos too.

Yes thats right Al, I picked up another TD05 evo turbo today , they look very well made. I see if I can get the flanges on ebay for it