shaved99gt

iam trying to find out a few things for this turbo by reading my compressor map the turbo is a holset he-351cw iam trying to find.I was able to find the definitions of the terms iam trying to find out thanks for any help

1.The flow rate @ which the turbo is most efficent also called the Island Flow. The number iam looking for needs to be in CFM's
2. Pressure Ratio-Ratio of compression pressures @ the island flow point (ambient vs. output) higher the number the better at compressing air
3.Surge Flow- Airflow @ the island (most efficent) pressure ratio @ which the turbo begins to "resonate". the number iam looking for needs to be in CFM's.
4.Effiency measure of power consumed by by a turbo compared to increase in induction pressure @ the highest efficeny point. The number iam looking for with be a precentage.

shaved99gt

TTT anyone please

JDMFantasy2K

holy ------- pressure ratio

shaved99gt

can you elaborate on that? why is this compressor map so different looking than other compressor maps?

shaved99gt

TTT anyone?

JDMFantasy2K

ok i'm no JD when it comes to turbo dynamics and ----, but i have plotted out a fair share of comp maps and i kinda understand them. The one i just posted is of a garrett t3 turbo 60 trim. A turbo which many here, including myself, run.

First of all notice how the two maps look different. Your map is a comparison of the different holset turbos, see the different lines and then the designations for them. So i guess they kind of layered different turbos onto one map, however there's only certain points for each turbo. If you look at the T3 map you can see all the efficiency islands, speeds, and the surge line. Ideally, you want to run a turbo through the centerline of the innermost island i beleive. Not sure if it makes a difference of a higher or lower pressure ratio, but if you're out of an island then it's usually a no no.

why do you need all this info anyway? I think it would be easier if the map had actual islands on it and if was with only one turbo.