I'm looking for the a/r's for the hitachi ht-12. I know they have a 51mm turbine & 57mm compressor.

 

C'mon, someone out there must have an idea! Guess if you have to

 

If they are not stamped on the turbine housings, I'm not sure if anyone will know. Did you find a set of larger housings?

 

No, I'm actually just screwing around with misc leftover fd parts from a single turbo conversion and turbocharging a prelude.
I had planned on using one of the stock twins originally but just picked up a garrett turbo from an older 300zx and now I'm not sure which to use. The comp and turb housings on the garrett are larger as well as the turb wheel, but only very slightly. However, the hitachi definitely has a larger comp wheel and seems as though it would be more efficient as long as the turb housing will flow enough for the 2.0L
Sorry to go off topic. If anyone else would like to take a stab at it please do!

 

Most of the older Nissan single turbos used a 60 trim T3. I can guarantee you that the Nissan turbo is larger than the HT-12.

Consider this...twin Garrett T25's are an upgraded twins path that some people have followed. Twin T28's are larger yet (they are T3/T25 hybrids). The T3 is even larger than those 2.

The other advantages are that the Garrett turbo is FAR easier to get parts for (flanges, CHRAs, housings, etc). If you are not happy with it, you have a lot of options. You can run a larger turbine housing very easily. You will not have this luxury with the HT-12.

My 2 cents...

Sonny

 

Very true Sonny. I'm still wondering why the hitachi's comp wheel is so much larger though. Seriously, the housings of the garrett are the only larger parts besides the barely larger turbine wheel. When both CHRA's are side by side they look quite similar in size.

 

You are talking about the rear of the compressor? Major? The front is a 41 or 42.

 

Heath: You can't compare two different makes of turbos that way. A good example would be the Toyota CT20. It is a massive turbo when you put one next to a Garrett T28, but CT20 is efficient up to about 220 hp. People have made 350 hp on the "smaller" T28. Things like blade pitch and the number of blades vary between manufacturers. The 2 models of the Ford Thunderbird TurboCoupe is another example. They had similar performance, but one had a relatively big (physically) Garrett turbo while the other had a physically much smaller IHI turbo.

When you're comparing within the same turbocharger family, then it's easy to do. For example, all of the Garrett T3 compressors have a compressor exducer (outer) diameter of 2.367". Is the inducer (inner) diameter increases (which directly effects "trim" in this case), so does the power potential of the turbo.

Sonny