How does A/R affect the compressor map? (or does it at all..)
#1
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How does A/R affect the compressor map? (or does it at all..)
I'm trying to choose the right turbo for my setup, and I'm getting a bit confused with all the compressor maps and A/R ratios and such. The search function told me more about what A/R was, but not how it is mathamatically relevent in turbo selection. Do you multiply your intended CFM at a certain point by A/R on the compressor map?
#2
The A/R ratio affects the compressor map quite dramatically.
If you go up in A/R you will improve your potential power, but it will take more impeller rpms to generate it. So for a larger A/R the map will 'stretch' up and right, losing some of the bottom left on the map.
The islands will also become a little narrower, as larger A/R ratios reduce the efficiency.
I hope this makes sense to you.
If you go up in A/R you will improve your potential power, but it will take more impeller rpms to generate it. So for a larger A/R the map will 'stretch' up and right, losing some of the bottom left on the map.
The islands will also become a little narrower, as larger A/R ratios reduce the efficiency.
I hope this makes sense to you.
#6
If you check out the Garrett catalogue, you can see the compressor maps for some of their turbos. Some of them show the maps for different A/R's.
Check out:
Garrett Catalogue
Check out:
Garrett Catalogue
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Re: How does A/R affect the compressor map? (or does it at all..)
Originally posted by Raptor13x
I'm trying to choose the right turbo for my setup, and I'm getting a bit confused with all the compressor maps and A/R ratios and such. The search function told me more about what A/R was, but not how it is mathamatically relevent in turbo selection. Do you multiply your intended CFM at a certain point by A/R on the compressor map?
I'm trying to choose the right turbo for my setup, and I'm getting a bit confused with all the compressor maps and A/R ratios and such. The search function told me more about what A/R was, but not how it is mathamatically relevent in turbo selection. Do you multiply your intended CFM at a certain point by A/R on the compressor map?
The compressor map should state the A/R of the compressor housing if different housings are offered. The turbine A/R has nothing to do with the compressor map, and vice versa.
The math involved in choosing a turbine A/R is extremely difficult, and will depend on your application. It is usually best to give your requirements to the turbo manufacturer or your local turbo guru, and have them choose the proper product. Believe it or not, this is what most of the pros do.
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