Enter the TD04HL....
The HL is the biggest turbine you can buy for the TD04 family. I can easily upgrade my wrx turbo to a 19T compressor wheel and comp housing and be into this turbo REALLY cheap. But here is where it gets interesting.
These turbos are not only laughed at, but most consider them "old school". I'd tend to agree with that.
But... The aftermarket has carried this turbo along. Greddy built a turbo kit for the 96-99 civic ( aka D16Y8 ). It used a 19T compressor wheel and HL turbine shaft in a 8.5cm housing. This turbo has been proven many times now on a single overhead cam 1996 civic to make 300whp and 300++ torque on 93octane. Google it, I'll wait. Lol. Compared to the ecoboost 1.6L, the old honda 1.6L isn't in the same league really. We can certainly spool any given turbo faster. Greddy snuck in a small detail. Volvo and saab had been using td04HL-18T and 19T turbos for a while... Greddys secret weapon was the 9-blade turbine wheel. It spools faster and flows more air vs the volvo and saab based 12 blade wheels. Didn't take long, but you can now buy a greddy 9-blade wheel very easily and reasonably priced in the aftermarket now.
Thanx to volvo.... The td04 can now be bought commonly in configurations rated at 400hp. And I even found one converted to ball-bearing and rated for 420hp (owens development in the UK ). Volvo guys have made 320-350whp on pump gas, and again, pretty low rent ecu/tuning setups. They typically do this running around 24psi on a 2.3L-2.5L engine. While we can't match there displacement, I think we are light years ahead on efficiency, fueling, and tuning, not mention, unlike the volvo guys, we are not scared to make more power than the rods can handle ( are we? Lol ). They are engine stress limited is what I'm getting at.
So... Having it all.... Volvo based td04... They come in 2 basic sizes. Td04L on the older L based turbos in the 13G/13T size compressors. And the newer 1999-2000+ td04HL-13T(and larger). The volvo turbine housing info is extremely murky. Seems like not even the volvo guys know what cars of what years come with what turbine housing. There are 5 that I know of. But only 2 that we need to think about. Those two are the angled 6cm and 7cm turbine housings. They come in straight versions as well, but the angled ones flow better. And the 5th one is the one pictured above, which happens to fit right on my wrx turbo as well ( remember L-turbine wheel only fits L housings ). In my case... I'm going with the biggest of all walks. The HL that comes in a volvo is a 12-blade. There is an 11-blade; but... Seems about the same. The 9-blade is what I will be using ( aka greddy turbine wheel/shaft ). The 9-blade is said to spool 500rpm sooner vs a normal 12-blade and flow more. That is ultimately what lead to move upto the HL over the L. The L vs the 9-blade may very well have the same spool time, while the HL will out flow the L by a large margin. Am I sure? Its time for pictures isn't it...
Google if you want more, lol.