Some more common versions and their specs:
HX35- By far the most popular. It seems to be the cheapest and easiest to find (which is likely a big factor in its popularity). It comes in the 8-blade (older) and 7-blade (newer) varieties. The larger exducer of the 8-blade will help it to spool faster, which is definitely a good thing with the A/R of the HX35.
HY35- It uses the HX35 7-blade compressor with a smaller turbine and A/R. Less power potential but better spool time.
HE351- The big dollar one of the bunch, but for the money it is (at least on paper) a good turbo. It uses the same quick-spooling turbine and A/R from the HY35, but a larger compressor wheel (although it maintains the same trim). In theory, it should spool quick and pull HARD. I guess the price is higher and there aren't as many of them, so that's why I haven't seen too many others.
I also found that specs for these turbos are particularly difficult to come by, so I thought I would post those all in one place as well.
HX35 8-blade:
A/R- 0.89
Compressor inducer- 56mm
Compressor exducer- 83mm
Compressor trim- 46
Turbine inducer- 69.5mm
Turbine exducer- 60mm
Turbine trim- 75
HX35 7-blade:
A/R- 0.89
Compressor inducer- 56mm
Compressor exducer- 76mm
Compressor trim- 54
Turbine inducer- 69.5mm
Turbine exducer- 60mm
Turbine trim- 75
HY35:
A/R- 0.65
Compressor inducer- 56mm
Compressor exducer- 76mm
Compressor trim- 54
Turbine inducer- 65mm
Turbine exducer- 58mm
Turbine trim- 80
HE351:
A/R- 0.65
Compressor inducer- 60mm
Compressor exducer- 84.582mm
Compressor trim- 54
Turbine inducer- 65mm
Turbine exducer- 58mm
Turbine trim- 80
HE341:
HY35 and HE341 are identical (some people often mistake one for the other). They use the same compressor and turbine wheels and would perform in a very similar fashion. The only differences I know of are in the housing. The HY35's exhaust discharge differs from the HE341 and the HE341 has a different wastegate. This is a non-vgt turbo
CREDIT THREAD:
Holset Turbo Specs. HY, HX, H1C/WH1C, H1E/WH1E - D-series.org
Holset HX30
The HX30 is suitable for engines of up to 5 litres capacity requiring up to 0.35kg/s of air at 3.0:1.
Aimed at medium duty applications, the HX30 is a well proven turbocharger on many 4 cylinder automotive, bus, agricultural and industrial applications.
Features:
Choice of turbine housing materials to cover a wide range of temperatures.
Compressor and turbine wheels selected for optimum airflow,efficiency and pressure ratio.
Fully adjustable compressor and turbine housing orientation.
Fully floating twin hydrodynamic journal bearings.
High efficiency compressors with broad operating ranges.
High pressure ratio capability.
Symmetrical twin flow turbine housings.
Superback compressor wheels for extended life and durability at high turbo speeds.
Variety of compressor and turbine housing flanges available.
MWE (Map Width Enhancement)compressor inlet. (Optional)
Sound suppression baffles. (Optional)
Watercooled bearing housings. (Optional)
Dimensions Holset HX30
Length mm 222
Width mm 217
Height mm 154
Smallest Mass kg 8
Largest Mass kg 10
Airflow kg/s 0.35
For Engine Capacity (litres) Up to 5
Output Range (hp) 90-240
Pictured here is an HX30 from a few different angles