Remanufacturing and „remanufacturing” – turbochargers challenge
During showcar trips, coachers from motoremo almost on every training spotted advertisement of firms which offers service of turbochargers. That leads to check what these firms can really offer. This is the way that create an idea of remanufactured turbochargers challenge.
Preparing for the tests.
We bought turbochargers for the test from the companies existing since a few years, they are known on local market.
A phone call from our customer in case of turbocharger failure in his Seat Toledo with BXE 1.9 TDI engine helps us with choosing a car for the test. Toledo has applied 751851-0004 Garrett Variable Geometry Turbine. Garrett by Honeywell do not sell spare parts for VNT turbo repair so only one option to make it works right is buying a new one or after Garrett reclamation in their factory.
It wasn’t hard to find “repaired” - with using fake spare parts – turbochargers. These falsified substitutes are made by China and European manufacturers.
That came to 3 turbochargers for our test:
- Garrett Original Reman
- Remanufactured turbo with using spare parts made by Asian manufacturer
- Remanufactured turbo with using falsified substitutes made by European factory
We take our test vehicle to workshop specialized with service cars from Volkswagen Group and it’s equipped with dynamometer. For the first test we used turbocharger which was repaired with using spare parts from European production. Turbine went test a pretty good what was a really big surprise for us. Power level was correct but torque was 10 Nm lower than with original turbo set. Until a engine temperature rised, vehicle was blowing out a blue smoke from exhaust pipe. On the whole engine rotates range, boost was undulated and wasn’t comparing with assumed pressure, especially in rotates range from 1800 to 2500 rpm. Considering that fact that engine works mostly on this rotates scale in city-drive, unstable turbine work may caused wrongly burning what lead to car smokes. There is a big chance that becoming soot may block variable geometry system. After dissembly boost unit we find out that used variable geometry system was not new, altought we were confirmed this is a new one.
Asian spare parts
Analysis of boost pressure in tested turbocharger with new core and new variable geometry system made by Chinese producer went not bad. In whole rotates range we were able to see boost was weaker or stronger that should be. This process has bad influence on burning in our engine but in this case, wrongly burning is not that destroying as in previous test. We were not surprised because a lot of workshops which offer turbines repairs are equipped in devices for settings exhaust flow over variable geometry system. Tested turbocharger is very popular product so calibration of this device is quite easy. Setting this device is harder if it needs to be done for calibration different, rare turbos because right calibration required a few new turbines and individual, specialize hoop-up for them.
However,we found the most interest things inside testing turbine. We find out that impeller applied in Chinese core is made from metal alloy with less resistant on temperatures.
Apply right material.
GMR235 alloy is applies in majority if turbochargers for diesel engines and some low exhaust gas temperature, gasoline engines. It can be indentify by hexagonal finish of impeller. This material sustain temperature u to 850 Celsius degrees.
If impeller has a triangle finished, that means it is made from Inconel 713C which can works up to 950 Celsius degrees. Garrett applies this stronger alloy in their GOR line. The other two turbines was build with a weaker alloy. Because of this, we can assume that these turbochargers’ lifetime will be shorter than the one with original core. Unfortunately we couldn’t test these 3 turbos for longer time.
Choose is always up to customer, however it’s worth to remember that prices of original turbochargers, remanufactured by producer are not much higher than these build with fake parts. We hope that our considerence will help You make buying decisions.