New Remnant Turbo Kit. Worked Fine for a Week, Now Acting as if I Have a Massive Boost Leak

[Jazee]

Hey guys, I have a 2020 Supra LE with a catless downpipe and Borla catback tuned with Ecutek. 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.

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 in case for mobile
Working
Not Working

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[zrk]

Reflex isn't getting power. Car is in limp mode.

lol no: I am dumb

 

[Jazee]

Reflex isn't getting power. Car is in limp mode.

What do you mean? I don't have a Reflex kit.

 

[zrk]

Yeah, nevermind, I'm just an idiot. The first and second log both have a CAN Error of 65535, I thought it was missing in the first log, but I just don't know how to spread sheet.

 

[Jesse DaBears]

Looks like a boost leak or wastegate arm issue still look at WGDC turbo is trying its hardest to reach targets.

 

[Jesse DaBears]

Plug back of turbo and pressurize the car see if its holding pressure or leaking.

 

[Jazee]

Looks like a boost leak or wastegate arm issue still look at WGDC turbo is trying its hardest to reach targets.

How can I plug the back of the turbo? Seal the exhaust tips? An idea someone else had was to pull the charge pipe off turbo and start car and see if it feels like a leaf blower like it should.

 

[Jesse DaBears]

How can I plug the back of the turbo? Seal the exhaust tips? An idea someone else had was to pull the charge pipe off turbo and start car and see if it feels like a leaf blower like it should.

If its at a shop tell them plug it from the downpipe or exhaust housing.

 

[Jazee]

If its at a shop tell them plug it from the downpipe or exhaust housing.

Not currently at the shop. I'm curious what this test will tell that the smoke test did not? This will pressurize the hot side?

 

[Jazee]

The mass airflow final is also missing the mass airflow target by quite a bit. I'd imagine this is consistent with an air leak somewhere, maybe pre-hot side?

 

[AJRMKV]

Damn... This is disappointing. I hope it's not a design issue

 

[Thraxbert]

Other posters are right. This is a boost leak somewhere in the install, or the WG arm has not been set to the right length. There's a 10 PSI difference between the two logs, but the wastegate duty cycle is maxed out.

The hot and cold side need to be smoke tested. What info has been provided from the shop (or relayed from the shop) is not very elucidating.

Is the downpipe torqued to spec?

Does the DP still have a gasket?

Has the cold side been smoke tested for a leak?

You're 1000000% percent that there are no leaks in the charge piping clamps? That all the couplers are squared up and snug? Clamps are tight? Applicable gaskets transferred from the old charge piping to new?

Has the hot side of the turbo been loosened and re-clamped to ~8 ftlbs to ensure a seal?

 

[Jazee]

Other posters are right. This is a boost leak somewhere in the install, or the WG arm has not been set to the right length. There's a 10 PSI difference between the two logs, but the wastegate duty cycle is maxed out.

The hot and cold side need to be smoke tested. What info has been provided from the shop (or relayed from the shop) is not very elucidating.

Is the downpipe torqued to spec?

Does the DP still have a gasket?

Has the cold side been smoke tested for a leak?

You're 1000000% percent that there are no leaks in the charge piping clamps? That all the couplers are squared up and snug? Clamps are tight? Applicable gaskets transferred from the old charge piping to new?

Has the hot side of the turbo been loosened and re-clamped to ~8 ftlbs to ensure a seal?

I've gone through all kinds of lengths on the WG arm, now it is set within spec and car is happy. The info I provided is exactly what the shop told me, along with a video with smoke drifting out of the compressor housing around the bolts the WG bracket uses to bolt to compressor housing.

Yes I am 1000% sure all charge pipe connections are secure, if they weren't that should've shown up in the smoke test as well.

Downpipe does not utilize gasket as it has a V band clamp to turbo. I did undo it and redo it while inspecting turbo and that did not help.

The cold side is what was smoke tested, pressurized through the inlet. I am not sure if this also pressurizes the hot side and checks for leaks there.

The clamp between the hot and cold side of the turbo has not been touched since install but it does not seem loose.

 

[Jazee]

Damn... This is disappointing. I hope it's not a design issue

I'm not sure. If this is not a stupid fix I'm missing and there is actually something wrong with the turbo, it is something Alec has not seen before through the hundreds of cars with their turbos. But that would be my luck.

 

[Thraxbert]

I admit that I'm skeptical of the seal on the cold side because in the "not working" log, the car was asking for over 30 pounds of boost, but the pre-throttle pressure sensor was only reporting 16-20 pounds. A boost leak from improper installation of the cold side is the most likely answer, here.

That said, I think loosening the clamp on the center of the turbo and ensuring the hot/cold sides are snugly together is a good bet. That v-band at the center of the turbo should be 8ft-lbs/96in-lbs. Easy to do on the car.

There's actually a gasket in the downpipe, it's the flaky graphite ring that's recessed into the clamping area. Just wanted to make sure it was still there.

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