Do any of you know of a turbo with a compressor A / R smaller than 0.7, as well a compressor side exducer larger than ~ 110 mm?

Thanks.

 

gt4508 will get you really close. 108mm compressor exducer and I think those things are like .65 or .69 maybe compressor ar.

 

Ideally, the turbo ought to be capable of up to 120 to 150 lb / min. I had read that the GT45 series peaks at about 110 lb / min -- and that is for a ~ 1.0 A /R. So a 0.65 A / R would be less than 100 lb / min?

 

I don't know, I haven't looked at the specs given the new demands of 110 lb a minute. Maybe you could take a look at the compressor map for the turbo that was suggested based on the two requirements of the original post and decide if it fits the goals of the now modified requirements. But thats just me.

 

Yes. The compressor map shows ~ 110 peak lb / min. That is doable, however, the efficiency is very low at that flow density.

Thank you for the suggestion.

 

One option I noticed is the Holset turbocharger.

Is this the correct method to measure the A / R with Holset turbochargers?

For example:

The compressor housing area ( A ) = 20 cm.
With the compressor wheel exducer = 100 mm, the radius ( R ) is = 50 mm.

Thus would the A / R be equal to 20 cm / 50 mm?
A / R = 0.4

I doubt the calculation would be 20 / 5 (where both units are in centimeters) since that calculation would result in an A / R of 4.

 

The A/R only applies to the compressor cover or scroll, it has no bearing on wheel diameters. It's calculated using the area of the opening, and the radius it's on.

This explains it pretty well. https://www.enginebasics.com/Advanced Engine Tuning/AR turbo ratio explained.html

 

Holset seems to provide one area, rather than the A / R ratio illustrated in the url you provided.
What method have you used to calculate Holset turbocharger sizing, from area to A / R?

If this is tough for the turbocharger forum people to explain, the Holset turbochargers are probably a poor fit for this application.

 

As far as i know, there is no direct comparison, but there are guesstimates online that get close.

 

OK. Here is an example of how I calculated the A / R from the Holset area.

Compressor exducer radius = 50 mm.
Holset stated area = 20 cm^2.

Then, I calculated that the radius of a 20 cm^2 circle is equal to approximately 25mm. Thus is approximate, since the area is likely a semicircle.

Add the compressor exducer radius (50 mm) and the radius of the area (25 mm) to get the, R = 75.

Thus, the A / R (20 / 75) is approximately 0.27.

 

But where does Holset measure the area? The area is typically smaller at the wheel, and larger as it moves towards the inlet/outlet. I don't see it as a 50mm circle as it leaves the wheel on a compressor with a 100 mm exducer. Why is the compressor a/r so important? Many don't even consider it as there are very few if any changes to be made on the compressor side.

 

The A /R ought to be proportional throughout. Per the url you posted, as the area increases, so does the radius.

Thank you. Post ought to say, turbine side.