[Jazee]

Hey guys, a bit of an outsider post because I have a 2020 Supra LE with a catless downpipe and Borla catback tuned with Ecutek. But a B58 is a B58 and this problem is really wearing me down. I just dropped in a brand new Remnant 65 Omega turbo kit. After receiving and installing the kit I was very happy with the quality, installation instructions, and customer support of Remnant. I was happily driving the car (babying it while in the etuning process) for about a week, enjoying my new T51R turbo noises, and all of a sudden started having issues after I went to drive the car after leaving the grocery store. Note that may or may not be relevant: Right before shutting car off to go into the store, I did a small launch in the wet with burbles turned on for a video.

On the drive home the car threw the drivetrain malfunction code and a couple codes for the wastegate. I thought no problem, wastegate arm just needs to be adjusted a few mm. After messing with the arm for hours, the car is finally happy with the length and is no longer throwing codes. However, I am still having an issue where the turbo whistle has all but disappeared (before it was very loud at even 15% throttle), and the car does not build boost until 4500rpm-5000rpm. Missing boost targets on the datalog by a mile.

I've double and triple checked for boost leaks at clamp connections, and ended up taking it to a shop for a smoke test. They found smoke coming out of the back of the compressor housing which they think to be the issue. However, after tightening the bolts, the smoke reduced significantly but the issue did not improve. I know this leak is not ideal, but I have a hard time imagining this is the main cause, since that cold side air is not under boost yet so therefore not technically a boost leak.

I have been in contact with Alec, the owner of Remnant, to try and figure this out. He believes it is an issue with the wastegate. I have tested the electronic aspect of the wastegate by removing the arm of the physical wastegate and ziptieing it closed and taking it for a drive. No change. I have also inspected the hot and cold side turbine wheels and they both are intact and spin freely. And there are no cracks or holes in the downpipe, or exhaust manifold.

This weekend I am going to inspect the physical aspect of the wastegate more thoroughly and see if the flap or the seat is somehow damaged and allowing boost to vent through the exhaust. If that is not the issue and a new compressor housing O ring does not fix it either, I'll be at a loss. I want to pressure test the hotside of the car tonight but I'm not sure how to go about that. I know I have to block the exhaust, but where can I pressurize the car from? Still the turbo inlet?

Is there anything I am missing? Is a slight leak through the compressor housing "okay"? I know it's not optimal.

I'll attach 2 datalogs, one with the problem evident, and the other the first pull I sent to the tuner while on base map when everything was working.

Google Sheets Link for logs
Working
Not working

[B58]

There really isn’t much to a B58 as far as having a boost leak. The obvious parts will cause a boost leak and you’ll know right away. The OEM wastegate actuator is obviously electronic. Once it’s bad then it’s bad and it would make no sense for it to not work and suddenly work above 5000 rpm and make boost. Its kinda rare for the OEM actuator to go bad, but it does happen time to time. I’m suspecting there’s something up with your new turbo that just hit the market. Let us know what you find.