After getting back from Washington, it was time for the biennial "regulatory work".

This looks familiar:
https://cimg3.ibsrv.net/gimg/www.mia...71b3d77f9a.jpg

No warpage on the manifold this time, probably because the car has only had one track day since the last one.

https://cimg8.ibsrv.net/gimg/www.mia...1b0b6668ca.jpg

Uh oh, what's this? Looks like the turbo ingested something and chewed up the impeller blades? I have no idea what it would be. There's a small amount of radial play in the shaft, but apparently that can happen if it hasn't been run recently and the oil has all drained out? I haven't seen any sign that the blades have hit the housing walls.

https://cimg0.ibsrv.net/gimg/www.mia...2140360bdc.jpg


--Ian

Not sure if this information is useful but in some of the Powerstroke Diesel groups I'm in on FB, it seems to be common knowledge in that community that some specific air filters when used will have your turbo looking like that over time. Apparently they don't filter well enough but it takes awhile for it to get to that stage and they refer to it as a "dusted" turbo. What kind of intake/filter do you run? I tried to go back in the thread but the vast majority of the images look like they're broken/missing.

Huh, I knew they'd broken external linking in new posts, but I guess it's true in old ones as well now? As a workaround, try loading it in a browser other than Chrome (either Safari or Firefox works for me).

I'm using a K&N filter that came with my FM2 kit long ago. It's possible it needs cleaning, I suppose?

--Ian

Wow, I'm no turbo expert, but that looks bad. Did you have an off-track excursion?

What does the inside of your intake tube look like?

You'll find significant amounts of garbage in the intake tract post filter and pre turbo if you suspect "dusting" is an issue.
​​​​​Remember, this is a street/track car and not a truckbrotruck playing in the dirt. I'd expect to see this on the turbo bolted to his Duramax tow vehicle before seeing it on the Miata. This car simply doesn't see the mileage or the abuse.

Maybe this is why it sounds like an angry vacuum cleaner all the time? :giggle: That's a bummer though, guess it's time for a bigger turbo, eh?

No, the car has only done one track day in the last two years (the last Miatas@MRLS event) and there were no incidents. Immediately before that event the turbo had been at ATP getting resurfaced, so I'm pretty sure the compressor blades were fine at that point. It's barely done any street miles since then either, covid has really put a dent in my street driving.

This is the filter:

https://cimg8.ibsrv.net/gimg/www.mia...943ca9b9ce.jpg

Inside the filter:


https://cimg8.ibsrv.net/gimg/www.mia...6439057541.jpg

Intake tube from filter side. The shininess is a bit of oil from the cam breather that got past the catch can. The sparkly things do not appear to be debris, I think it's just fibers in the tubing that are shining because they're wet with the oil.


https://cimg9.ibsrv.net/gimg/www.mia...41c12c919e.jpg

And from the turbo end:


https://cimg4.ibsrv.net/gimg/www.mia...1839301c99.jpg

Intake plumbing on the floor:


https://cimg1.ibsrv.net/gimg/www.mia...2b39838614.jpg

And when it was assembled in the car:


https://cimg7.ibsrv.net/gimg/www.mia...e79233dc63.jpg

--Ian

Duramax has been sold, I've got a Ford now! :)

The damage to the turbo is disappointing but I don't know if it's fatal, the car was still running great the last time I drove it. Which was, uh... a while ago. :) Need some pro input on it.

--Ian

Has it tried to kill you yet? :giggle:
I r professional... something? I say send it. :bigtu:

No, it's an F-250, not a Mustang. :)
Showed the pics to a friend at an Evo tuning shop, he says he sees evidence of wheel-to-housing contact and suggests that the shop who reassembled it for me last time may not have aligned it properly. Sigh.

--Ian

The turbine looks OK at, least. Sigh. I'd really hoped this would be the time it all just went back together without anything complex.

https://cimg8.ibsrv.net/gimg/www.mia...803ee6b1eb.jpg

--Ian

I took the physical turbo over to said friend's shop and he looked at it in person. Confirmed that there's been wheel-to-housing contact and said this CHRA is done. You can see the contact in the edges of the blade being bent over slightly:


https://cimg5.ibsrv.net/gimg/www.mia...cea2d498cc.jpg

Cause is unknown, the housings are tight so it was probably some kind of debris that got into the intake. I still have no idea what that could have been, it's never been run without the filter. I guess I'll pull the intercooler off and see if there's anything stuck in there.

--Ian

Bummer man, sorry.

Sad to see that damage to the wheel, but there are solutions. Plenty of options to fit an OEM clone billet wheel and have it balanced, should be 200-250$ to get it running again like new :)

I believe this is one of the fancy new Garrett GTX trubos? I can't keep track of anyone's builds anymore.

​​​​​Maybe Garrett can do a CHRA exchange? Might be worth dropping the folks at ATP a line and see what they say. Regardless, sorry to see stuff like that especially with your use. Good news is you've got a few weeks before you have to put it back together, just make sure you get all the 110 Leaded out of the tank before it goes back together. :laugh: I'm sure the RX-7 will love the stuff!

Correct, it's a GTX2863R.

No leaded in the Miata, it's got 100 unleaded in it.

I talked to ATP, it used to be that Garrett would offer a "rebuild" of a GT/GTX turbo by giving you a discount on a new CHRA when you brought in a damaged one, but that program is over. MSRP on a CHRA is $900 and they suggested I probably need a compressor housing as well if the blades have contacted it. That's a supercore which is $1100. I haven't pulled the compressor housing off yet to confirm that. The good news is that even though Garrett no longer lists this turbo in their catalog, they do still sell the parts.

I'm undecided what to do. 2 years ago I decided I wanted to BAR-swap an LS motor into it and started shopping for donors, but then covid hit and everything got put on hold. For now I'm going to finish the uh, "regulatory" work and think about it a while.

Got everything bolted back together last night, had my daughter start it while I stood by the open hood checking for fuel leaks. Didn't see any, it managed to start (battery is iffy) and ran, but seemed to be running more slowly than I expected. Not sure if that was just me unused to a stock idle or if there was something wrong, I had her shut it down while I checked plug wires/etc. They were all fine, so we went to restart it and the battery was having none of it. So I stuck the battery charger on it and called it a night.

--Ian

https://cimg8.ibsrv.net/gimg/www.mia...6f7e73e9c0.gif

Sorry to hear about this Ian. A friend sent me this picture from the track today, I thought you would like it too, I didn't think this was your car.

https://cimg9.ibsrv.net/gimg/www.mia...6989561cd1.jpg

Nope, not mine. That one looks to be naturally aspirated, plus it's got tupperware all over it. :)

Hooked on Driving is at Sonoma tomorrow as well, I plan to be there with the M3.

--Ian

But did you die?

Oof. Cold Gordon.