im having trouble with recently increased boost on my car.
Was using a Ct26 in perfect condition for around 2 years, boost was regulated by wastegate, so it was going around 0.8bar. After a while due to maf issues , when cold(leaning out in low rpm even after adjusting the idle screw) i decided to go with aftermarket ECU and increased boost. Problem was that as soon as i upped the boost to ~1bar and drove for like 30KM the turbo blew totally by bending the shaft and destroying the impellers. It was not possible to rebuild, so i went a CT20B. Everywhere i read they say you can boost this one safely at 19PSI. So there i went 19PSI. Problem is after like 2000km the turbo axial play increased a lot, it started smoking and it ended up also having a lot of radial play leading to a rebuild with replacing the compressor wheel as the old one was touching the housing and was damaged. After disassembly the rebuild company found a very small particle of silicone like 0.5mmx0.5mm on the nozzle of the axial bearing, so we decided that was the actual issue not the boost. There i go new rebuilt turbo, boosting again 19 psi and after 1000KM problem, it started smoking again. I checked it and there is a lot of axial play , no radial play at all, but it seems the axial is big enough for the turbo to smoke. Im for a rebuild again, but the question is, what is going wrong, are the CT20B incapable of producing safely 1.25bar ? Im not using a highly modified engine. Gen2 head, cams are stock from N/A and a 3inch freeflow exhaust. That is pretty much it. Any suggestions are appreciated.