Turbo compatibility

[Daphne]

Hello everyone, I recently bought a car in the US that has an ej20x swapped into it (pre-fl). It has the stock intake manifold from a 2.5l on the 2.0 long block. So far the car has a catless dp, exhaust, intake, upgraded fuel pump and boost controller. It runs pretty decent but it's going to my tuner for a few pulls on the dyno to straighten things out.

I'm starting to plan and look at the next stage for more power. I was thinking 740 injectors, a nice tmic (maybe avo or process west) and a bigger turbo. It has came to my attention that this is a very unique fitting turbo (vf38) and haven't been able to find much that will bolt up. It looks like my options are either

a stock vf44
rebuild the vf38 with vf34 internals
kinugawa 20t bolt on


What do you guys think is the best option to push towards 200kw?

My initial plan was a vf52 rebuilt for quicker spool but it looks like there is a lot to replace if going that route (dp, headers, maybe tmic and not sure what else). Thanks for the input, going to dig through the forums a bit more and see what I pull up.

[bigBADbenny]

Iirc the kinugawa has a slightly larger exhaust housing than the vf38, meaning more top end.

Or you could get a fancy custom chra for a stock td04hla.

The vf38 is rated as weak in the chra department, probably why they’re upgraded with vf34 internals.

Stav-tech reports the HE221w bolts onto a VF exhaust housing, the stock housing requires some machining to clear the turbine: afaik no one has done this mod yet.

https://www.google.com.au/search?q=site ... s-wiz-serp

[Daphne]

The HE221W conversion is pretty interesting. So pretty much you buy a HE221W and use this (http://shopping.kinugawaturbo.com/turbo ... 04l-1.aspx) for the exhaust side? Just need a longer actuator and to have the lip of the inlet machined down? This would be a direct replacement for a vf38? Looks like it would be the way to go.

[bigBADbenny]

The HE221w exhaust wheel fits a 7.5cm2 housing.
So a stock td04hla housing at 7cm2 may require some porting.

6cm2 housing will be way too small.

[Daphne]

Having a hard time finding a 7cm2 housing. In this video ( https://www.facebook.com/STAVTECH/video ... id=SEO----) he states that mamba and kinugawa sell them but can't seem to find one for sale. All the ones I see are 6cm2.

[bigBADbenny]

For what application:
Eg lgt twin or subaru single scroll?

For single scroll subaru, stav says to port the exhaust housing for clearance.
I guess this applies to all td04 housings.

[Daphne]

Twin scroll, I'm looking to replace the vf38 without doing the downpipe, up pipe and header.

[bigBADbenny]

Generally the td04hla is regarded as a better option than the vf38: more likely to be reliable.
Aftermarket versions eg kinugawa have a larger exhaust housing and will require a retune to suit.

But the first step is to diagnose the failure mode of your turbo, usually related to boost leaks, clogged banjo filters, stuck pcv.

What’s the actual issue?

[Daphne]

Turbo hasn't failed or shown any signs. Just too slow, the vf38 runs out of breath too easily. Car will be getting a Blackstone labs oil analysis before the next round of upgrades so I'm getting parts and a plan together.

Banjo bolt filters have been removed, currently pro tuned by Mike Botti about 2k miles ago, planned on having him do the next tune as well.

[bigBADbenny]

Ok. gotcha. This all makes sense now!

So apparently a stock td04hla can have a compressor upgrade, with no porting, that allows it to hold more boost to redline: this is according to rose rage turbos. The mod costs around AUD $1200.

I’d imagine this mod would perform similar to a vf52 on a 2.5l.

Gcg turbos offered vf34/38 hybrids in the past, and these come up for sale occasionally.

The kinugawa (etc) td04hla 19 & 20t have an 8.5cm2 housing and are good for 220wkw maybe.

My choice would be the HE221w core with the surge port compressor cover in the 8.5cm2 housing or a ported for clearance stock housing.
The holset compressor cover will need some modding to suit a Process West or Cobb style tmic, plus the appropriate stock location inlet.

Alternatively convert to subaru single scroll, jdm sti twinscroll, stock, aftermarket or hybrid uppipe: adapted for jdm sti, single scroll or aftermarket flanges or vee bands.

It really depends on scope and budget.

But as regards the compressor map, the HE221w is similar to a small frame BW EFR.

[Daphne]

Yea I'm thinking the HE221W but can't seem to find an appropriate turbine housing. All the ones I see from kinugawa and mamba are listed at 6cm. Going to talk with a local turbo builder to see how difficult it would be to make the stock housing work. Would much rather buy a new housing that is a guaranteed fit.

[Stifull]

Mightycarmods guy put a VF34 onto their personal Forester. It had been modified to fit. They did it because there are very few reasonable priced turbos that fit on. See here are around 6min30sec for details of the VF34.. This is a good Video for those doing turbo mods. I am watching it for the 4th time atm..
https://www.youtube.com/watch?v=A2Po7fMbO_A&t=156s

[bigBADbenny]

Yea I'm thinking the HE221W but can't seem to find an appropriate turbine housing. All the ones I see from kinugawa and mamba are listed at 6cm. Going to talk with a local turbo builder to see how difficult it would be to make the stock housing work. Would much rather buy a new housing that is a guaranteed fit.

I contacted stav via pm and he confirmed porting the stock td04hla housing should suffice.
And that the porting is minimal, a few mm at the most, probably around the largest diameter of the volute.

So you could reach out for a stuffed td04hla in Aus.

Whilst I’ve been on the lookout for a blown td04hla-19t, I’ve stopped short of emailing kinugawa regarding if the exhaust housing is available separately.

As for HE221w the most affordable items in aus are from China, then Poland, Uk and USA, I wish they were more available here!

Or look into the vf34 hybrid idea.

[bigBADbenny]

So this question (upgrade a vf38) is asked a lot.

Here’s the latest post on a local FB group.

The comments confirm the vf38 exhaust housing can be machined (eg GCG turbos) to suit a next size up chra, presumably using any rhf55 parts.
Said turbo producing 20psi, of course I asked at what rpms specifically

https://m.facebook.com/groups/107835545 ... oser=false

…

[bigBADbenny]

This is the mamba td04hla-19t…

https://www.shop.mambatek.com/GTX-Turbo ... 1-0370.htm

My tuner has tuned over 40 of these, and they apparently hold up well