+- STD (https://www.superturbodiesel.com/std)
+-- Forum: Tuning (https://www.superturbodiesel.com/std/forumdisplay.php?fid=6)
+--- Forum: Engine (https://www.superturbodiesel.com/std/forumdisplay.php?fid=7)
+--- Thread: Compressor Maps, and Volutes (/showthread.php?tid=7649)
Compressor Maps, and Volutes - barrote - 03-05-2017
Hello fine people,
Like many others my experience with turbos is made of trial and error, but there´s no reason not to follow basics.... questions:
Does anyone have maps from Garret VNT compressors? that is willing to share?
What is the relation of the A/R of the compressor volute? does it play any role in the graph change? like it does in the turbine housing?
As far as i understood graphs are predictable behaviour of the compressor tested at certain conditions, but what is the relation in delta P if turbo inlet is 2000mb absolute pressure? and mass flow?
Does anyone know the standard conditions for this testing? or does the diff brands have their own diff test parameters?
Thanks in advance
RE: Compressor Maps, and Volutes - awsrock - 03-05-2017
I have read that the A/R of the compressor housing has much less effect on the map than a change in the turbine housing would. I have also read that a larger housing is sometimes used to help larger turbos be more efficient at lower speeds...although I didn't find a reason for that.
I have a TD05-16g which has a housing nearly the same as the stock T3 but it can flow 38 lbs a min (very high speed) while on the other end I have a bwS200 that has a housing that is just huge...not really meant to be compared to each other, just saying...
RE: Compressor Maps, and Volutes - Turbo - 03-06-2017
look and search on http://forums.tdiclub.com/ there has been written a lot of this,
look what specially tdimeister and manny others has written
if you have same temperature at inlet and pressure is 2000mbar absolute pressure the map look the same but mas flow is about double and effiecncy line is the same , if you change temperature from reference temperature you need to use generalized parameter for changing condition for masflow rpm lines etc that makes it roughly correct. just calculate efficiency of the stage and stay at 70% at high flow and it is ok, regarding turbine you can calculate efficiency and look at back pressure as you know, depending on generation if we speak garrett VNT the older the wurse effiency, since egr need to work it has not been that of great importance to have low back pressure, a really stfied construction of this is for example garretts sst turbos, great compressor but back pressure.....
or simply just use match bot and save lot of time regarding compressor part calculations