Has anyone used a Holset HY35?

[boosted79]

I haven't looked at the compressor map yet for a 3.4L or 3.5 L 930 application but I have an HX30, HY35 and a HE 351 CE sitting on my bench. I think I read in a thread where someone was running an HY35. All have a 9cm2 turbine housing which I have to convert to A/R after I measure the radius of the turbine wheel. All have internal WG's so that would have to be held shut or welded. I found a thread that shows a 9cm2 to be a .65 A/R.

[Tippy]

They light with the gas pedal on Supras from what I've read.

I think they max out at 450hp.

Was planning on running twins one day.

They like high boost though to get to 450. You'd probably have to be over a bar to accomplish.

[boosted79]

Found some data. The HY35, officially known as an HE 341, has compressor dimensions of 56mm x 76mm and the hot side appears to be .65 AR. This compares to a GT 3582 with 61.4mm x 82 mm compressor and hot side A/R of 0.63 up to 1.06. Anyone have the compressor dimensions and hot side A/R for the different K27 variants?

[Tippy]

HEXXX is the newer version, not the official name of the HY35. Pretty much same specs, but newer version.

[Tippy]

I would dare to say the AR is closer to the 0.5X than 0.65.

It is tiny! I had one.

[copbait73]

Just to clarify, A/R is meaningless except within the same make, model turbine housing family. For example, I can have two turbine housings of 1.0 A/R, one the size of my palm and the other the size of my couch.

[Tippy]

Just to clarify, A/R is meanless except within the same make, model turbine housing family. For example, I can have two turbine housings of 1.0 A/R, one the size of my palm and the other the size of my couch.

Yep, 1.0AR on a "Stage 5" is drastically different than a 1.0AR "Q" trim turbine.

Plus, the AR from cm2 conversion is just an estimate that's been spread around the web. I can tell you, I feel it's really off but it keeps making the rounds.

Tenths of an AR can make a huge difference in spool time and max HP capability.

[unclebilly]

The HX35 was a common turbo used on Cummins Diesels in Dodge 3/4 and 1 ton trucks from 1995 - 2002 and possibly beyond. I have a core one if anybody wants it.

[copbait73]

Well Holset and KKK both started with many licensed Schwitzer designs ( now Borg Warner) and we used actual turbine housing areas at the turbine entrance called the tongue area. This is carried over in their designs so some still use an actual AREA vs. Area/Radius.
AiResearch, then Garrett, now Honeywell always was an aerospace spinoff so carried the A/R.

[boosted79]

[QUOTE=copbait73;8446306]Just to clarify, A/R is meaningless except within the same make, model turbine housing family. For example, I can have two turbine housings of 1.0 A/R, one the size of my palm and the other the size of my couch.[/QUOTE

Agree, A/R alone is meaningless unless it is used in conjunction with the compressor map.

[Tippy]

Well Holset and KKK both started with many licensed Schwitzer designs ( now Borg Warner) and we used actual turbine housing areas at the turbine entrance called the tongue area. This is carried over in their designs so some still use an actual AREA vs. Area/Radius.

AiResearch, then Garrett, now Honeywell always was an aerospace spinoff so carried the A/R.

So the AR to cm2 is accurate? The one a lot of Japanese car forums and Dodge truck forums use?

[Speedy Squirrel]

Originally Posted by Tippy

So the AR to cm2 is accurate? The one a lot of Japanese car forums and Dodge truck forums use?

There can be no analytical comparison of the two numbers among turbos, only an experiencial one, i.e. "the Garrett 0.84 behaved about like my BW 14cm2".

The cm2 is the "A" in A/r. It is the area of the nozzle going into the turbine wheel, sometimes called the throat of the turbine housing. The "r" is the radius from the dynamic center (center of the turbo axis is usually close) to the centroid (don't want to go into it) of the nozzle area.

So you can see that A/r has units of either inches or centimeters, and it depends on the housing design and turbine wheel size.

Each way has its pluses and minuses.

A/r is directly used in the calculation of turbine wheel impulse/momentum, but does not give an immediate indication of flow from a practical application viewpoint.

Area gives a clear indication of flow area (size of the hole feeding the turbine), but must be matched with the dynamic center measurement for an understanding of energy transfer to the turbine wheel.