So, before I get jumped all over, I will set some ground rules:-

Standard location/fit
Can be twin scroll
Not looking for compromise between spool and power, just spool speed
2lt engine
TMIC
Open to all the tricks for faster spool

This is theory but might lead to something else but just wanted your opinions.
Actual experienced answers would be good but happy to go with what's on paper as well.

Thanks guys & girls

 

hybrid td04

 

In theory, if you use a turbo with the exhaust turbine changed from 12 blades to the new 9 blades, you have better Spool and better peak power.
Mamba and Kinugawa manufactures these exhaust turbines, to hybridize an original turbo, after making that change you have to balance the whole. High speed rolling.

 

If staying with Impreza, I'd say the turbo that came with the US wrx (td04 with no letters, with a 13t comp wheel). I'm not sure if this was standard on any of the classic UK imprezas, or I'd they were all TD04L exhaust wheels.
If any old Subaru, maybe the te035 from a Forrester?

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Regarding the 9 Vs 12 impeller wheels, and the lower blade count being better for both spool and power: personally I don't buy it. I think you can have either less pressure difference across the wheel (lower blade count) leading to higher total flow, but worse spool, or the other way around.

 

as shrek mentioned the hybrid td04. id love to see someone put one on a 2ltr sti and have it mapped and see the results. im guessing as a purely off the line car it would have to be pretty quick?

 

Well, that could be a good start as I have a Blouch TD04 19T hybrid and that was the Turbo I was thinking of

 

I'll be running something very similar to a blouch td04 19t myself shortly (once the UK starts up again... 3 months?)

I am currently running a td04HL-15t (so smaller than the 19t), and it definitely does not spool as quick as a standard fit td04L - at least a couple of hundred RPM in it (probably mainly because the HL hot side). I see 1.2 bar at about 2700 RPM, and expect this to move slightly to the right with the HL-19t.

Tbh i don't know for sure if Blouch use a HL hot side, but i think they must for a 19t compressor wheel.

 

Good point the issue that it has fewer blades and the surface is less, but on the other hand the length and design of the blades is different and they are longer, I thought the same as you until I managed to see the comparison of both turbines and the truth I think the design is good. I share some photos of the original 13T VS the Kinugawa with 9 blades.

 

I understand that only what changes is the turbine side. Increasing the compression wheel and keeping the same casing warm. In theory, the hybridization from 13T to 15T or 19T would not add more LAG, but well that is in theory since whenever the purchasing wheel is enlarged it weighs a little more and a little more LAG can generate, but this is minimal and what That adds in flow compensates and is worth the upgrade.

 

I think the TD04L13T are all the same both UK and USDM models.

 

Oh, actually yes, I was wrong

 

Very interesting photos - thanks for posting! Interesting that they also clip the wheel a bit - this should add some extra flow.

Is that a TD04xx turbine? If so, do you know if it requires modification to the exhaust housing at all (for clearance)? I've just modified my CHRA, but I don't think my little lathe will fit the exhaust housing
Btw, and not that it makes any difference, but the CHRA you have there isn't a normal td04 CHRA, right? My exhaust shield at least looks different.

Generally, I've been very impressed with the Kinugawa and Mamba quality - they were a bit of a joke previously, but at least all the parts I've had from them so far (to be fair only oil feed line, compressor cover and compressor wheel) all look to be fantastic quality.

This is taking the thread a little bit off-topic, but I'd be very interested to know your turbo spec you're building there - and also any dyno graphs afterwards I was planning on dynoing my td04HL-15t before upgrading, but unfortunately i ended up with an exhaust leak on the downpipe gasket, and when it was all apart I thought I'd just fit the hybrid wheel anyway. The ideal comparison I'd want to make is a TD04L-19t vs a TD04HL-19t, but it's hard to know what graphs are what on the Internet... Usually people just know "it's a hybrid td04", but that can mean lots and lots of different combinations.
My interest is mainly academic, but on lots of other cars that come with td04HL-19t turbos, they seem to make up towards 340-350 regularly, and the Subaru's are lagging behind for some reason.

 

I am glad that what I share is useful to you, and if I, like you, am very interested in the good and concrete information of these modifications and the turbo hybridizations.
I will tell you what you ask me.
My turbo is a Subaru GT / WRX Original from the USDM market as well as the same as the UK. It is a TD04L-13T turbo.
In the photos I will put the OEM part number of the Mitsubishi turbo.
What I did was just take apart the "CHRA" by swapping the exhaust turbine for the Kinugawa 9 Blades. Then send the set to balance at high speed to a specialist.
The turbo behaves very well, what I cannot given the circumstances of my assembly is to assure you if it has a better "Spool" since I made the mistake of mounting two updates in a single assembly.
Multiple "Equal" and turbo Hybrid.
The manifold, as is well known, improves everything, but it always generates a little more "LAG" due to the length of the pipes. That the multiple Equal does not give LAG is a lie. The original manifold "UNEQUAL" since both manifolds on the turbo side are very very short helps to keep the turbo revs giving better response. I explain?
What I can say is that the hybridization of my turbo gave me a very good margin of response in mid and high. The engine is more comfortable and responds better. And it does not stay in a high regime as the common TD04L does due to its narrow output. This turbine improves on that. The flow is obviously better and allows a better demand at high speed.

The 19T model is very interesting, it has a compressor turbine with more diameter and more flow and it is said that it can generate up to 300 HP, maybe something more.
It would be very interesting to try a TD04L or td04HL turbo but with the 9-bladed turbine. I think it would be the ideal of both worlds.

And finally to your question of whether to adapt the exhaust casing, no. Although the Kinugawa turbine is longer it does not affect anything, it fits perfectly in the original housing of the Turbo TD04L-13T. It is Plug & play Literally. (I had the same fear until it reached my hands and I mounted it).
If you have any questions or anything else that can help you do not hesitate to do so.
I am taking advantage of Quarantine to be on the forums.
OEM TD04L-13T USDM GT1999 MY99 IMPREZA



http://shopping.kinugawaturbo.com/mi...lfaster-2.aspx

 

Cars with stock TD04-HLs, such as Volvos, have larger capacities and hence bigger numbers. A 2.5 Impreza would be a better comparison. But I think maxing out both the exhaust housing and compressor you will end up with very similar performance to a VF34/35. I think the small L housing will be the key to the spool and therefore the USP of the turbo. If you increase the housing, I think you may as well use a VF series or similar unit.

 

Generally the displacement doesn't seem to impact peak hp from what I can see for other turbos, but spool point is.

I'll dyno and/or log my car when it's mapped, to see what the spool point actually is the 15t was great, so I'm hoping I haven't ruined it.

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