Blown turbo > damage downpipe > causing turbo blown again?

[Henrythelam]

Hi all, here is my story
my turbo blown when doing a dyno pull,
the turbine wheels on the downpipe side flying out and hit the catalyst and a little visible damage on catalyst can be seen

I got the turbo replaced, the shop tell me that it is a "reinforced" IS38 with upgraded parts,
shortly after the replacement, I could hear a small whistling sound when spooling but the shop said it is normal

Eventually after 2000 kms, one day the whistling sound suddenly became lounder,
sound like a hose is loose, to verify the thing, well, I step it hard (wrong move)
the whistle sound gone and lots of white smoke coming out from the exhaust
that moment I know the turbo blown AGAIN and I was fucked

I go back to the shop to claim for warranty
the shop bought the turbo down and found that the turbine rod was snapped
none of the turbine wheels fly out this time

the shop claim that the catalyst being damaged last time is getting blocked
and heat built up at that section trapped heat between the catalyst and turbo
causing the turbo to blown like this

he said the 200 cell downpipe needed to be replaced and it is not the problem of the turbo

I think he have a point
but considering that the turbo came from him
I would like to seek for professional opinion from you guys
many thanks for your patient and input in this

 

[Diggs24]

Did they not recommend replacing the downpipe the first time the turbo blew? If they did and you didn't want to then that is on you. A damaged cat will prevent exhaust flow causing the turbo to work much harder to make target boost.

 

[Henrythelam]

Did they not recommend replacing the downpipe the first time the turbo blew? If they did and you didn't want to then that is on you. A damaged cat will prevent exhaust flow causing the turbo to work much harder to make target boost.

He did tell me the possible "heat spot" on the damaged cat
but he did not mention anything about turbo will blow because of it
it this true that the turbo blow because of this?

 

[Diggs24]

It sure can. I see you added pics, that helps. That slight mark is all there is? I don't think that would cause a huge restriction. You should also look at the backside of the cat material as it can melt there too.

A shaft snapping is usually 1 of 2 things, either poor lubrication or overspinning. Who is your tuner?

 

[Henrythelam]

It sure can. I see you added pics, that helps. That slight mark is all there is? I don't think that would cause a huge restriction. You should also look at the backside of the cat material as it can melt there too.

A shaft snapping is usually 1 of 2 things, either poor lubrication or overspinning. Who is your tuner?

I am APR stage 2
I donno if it would cause overspinning?
for the lubrication... I am not sure if any oil line was broken

the shop said he will get a endoscope to confirm his theory

but I wonder if it is the case that heat trapped at downpipe would cause the shaft to snap??

 

[torga]

You're on Stage 2 with what looks like an OEM downpipe? Correct me if I'm wrong, but I don't know of an aftermarket DP for the R that has a cat immediately after the turbo - looks OEM to me. Could be another reason why it's getting so worked up - not enough flow behind the wheel, causing it to spin faster.

 

[Diggs24]

OEM cats aren't 200 cell.

 

[torga]

I'm just going by OP's photo of the DP. Haven't seen an aftermarket one like that.

 

[oddspyke]

You're on Stage 2 with what looks like an OEM downpipe? Correct me if I'm wrong, but I don't know of an aftermarket DP for the R that has a cat immediately after the turbo - looks OEM to me. Could be another reason why it's getting so worked up - not enough flow behind the wheel, causing it to spin faster.

IE DP cat is in factory location. I think a few others too.

 

[torga]

IE DP cat is in factory location. I think a few others too.

Thanks! Disregard me, then.

 

[vw671]

Maybe a turbo with an upgraded shaft next time...

 

[Henrythelam]

Maybe a turbo with an upgraded shaft next time...

It is a upgraded is38
The shop claimed that it got a reinforced bearing, shaft and turbines

 

[Henrythelam]

Thanks! Disregard me, then.

It is a Remus 200cells
some said catalyst placed closer to the turbo have a larger restrictions but higher efficiency
I can't tell the difference

 

[vw671]

It is a upgraded is38
The shop claimed that it got a reinforced bearing, shaft and turbines

In your OP you said only upgraded wheels and bearings...are you sure that is a upgrade shaft?

 

[Hoon]

The shaft itself isn't inherently weak, but it often becomes the failure point when other issues are at play (bearing wear or a TCU tune issue that slams the throttle shut).

This turbo was likely overspun to hit the boost target because of the added cat restriction from damage after the last failure.