GT2871R Turbine Damage, pic inside

[neech]

So I took my gt2871r off and found this damage to the turbine wheel



Has anyone ever seen anything like this?? I didn't think this could happen with the turbine wheel being inconel and everything! I guess anything is possible. I need to do a compression test to make sure everything else is ok.

The engine is an s14 sr20 with AEM, HKS cams, supertech valves, ferrera valve springs with crower ti retainers, built bottom end, etc... I'm thinking the previous owner, or myself, got a little too crazy with the 2-step, or maybe a combination of 2-stepping and timing too retarded. There is no egt gauge on the car: I will order one as soon as I order a new turbo to replace this one.

I called ATP and a new centersection for the 2871R is $844, but I think I'll just go with a 30r. Anyone interested in buying the housings? You could have a brand new centersection

Thanks in advance for any insight!

[SoguRacing]

look like there was some sort of friction in the housing. never seen it myself.

[enjoisk8board891]

damn dude...that sucks. I have no clue how that would have happend but good luck finding a new one! let me know if you find out the exact problem

[Massimo Power]

ive seen that many times... it happens when you dont have a very good air filter. Tiny pebles and sand get in and mess up the fins that are spinning at 30k rpms..

unless thats on the exhaust side... which would be an indication of running too lean and hot and slowly disinigrading the wheel from the faster hotter points on the outside...

[pwr-adr]

damn that sucks man!

[timtiminy]

neech: pm me a price on the housings. also pm me a price on the whole thing with center section.

[480sx]

Im gona support your idea that you(or previous owner) over did it with the 2-step/anti lag. Could also be to much timing retard. The turbine just looks like it overheated. EGT gage is a must when your using an anti-lag/two step setup.

[Def]

Looks like 2 step damage to me. Doesn't look at all like foreign object damage to me.

A bad air filter erodes the minor diameter(inducer) of the compressor wheel. That's the major diameter(also inducer) of the turbine wheel.

[S14DB]

Looks like shear on the turbine wheels. I would say bad misfire/EGT. Seeing how you are using the AEM 2 step. I think you enjoyed that a little to much. Get a turbine designed for that if you want to do it often.

[Def]

It's definitely pure heat damage due to the rounded appearance of the "nibbles" out of the blades. A shear failure is going to be more jagged.

[neech]

Yeah I'm still thinking its heat damage.. A guy from AGP (not atp) says he is 100% sure its due to something falling into the turbine, but due to the consistency and shape of the break, I'm really thinking its heat damage. I will take the head apart this week and inspect everything and post an update just so its on the record. And I dont think it was hitting the housing. This turbo is practically brand new and the GT bearings are stout. It spins very freely as it sits now: One flick of the wheel and it spins for a good 3 or 4 seconds. No shaft play.

As far as getting a turbine thats designed for it... I thought GT turbos were about as tough as they get? Since the turbines are made of inconel, they can withstand much more heat than the T series turbos. What turbo would be better suited for 2 stepping conditions?

Either way I need an EGT!! $1200 mistake.. Its a shame these turbos are so expensive to rebuild.

[Def]

Can't you just buy a turbine wheel and get it balanced? I have heard that shops can't balance a GT turbo, so if that's the case you could toss it on and hope for the best. Gotta be better than scraping the CHRA.

[480sx]

Def NOT FOD damage. I have seen FOD damage before a couple times and it looks completely different.

Its not a 1200 dollar mistake lol. Im probably about to make your day..

Send your turbo out to a rebuilder. Pay 150-200 bucks(Maybe more idk exactly) to get a new turbine shaft/wheel. Pay the balancing fee, and the cost to re ring the shaft. Then your set.

To balance a turbo, you take the shaft and the compressor wheel completely out of the CHRA, the CHRA has nothing to do with the balance of the rotating assembly. They index your compressor, and spin it on a balancer then take a bit of metal out where its needed with the turbine/compressor outside of the CHRA.

But hey if you wanted to just get a new turbo ill take that 'junk' GT-R CHRA off you, 200 sound fair?

[mayco_86]

Wow thats exactly what happened to my brothers turbo. The exhaust side looks exactly the same. Dont know what went wrong with it either.

[Def]

Originally Posted by 480sx

Def NOT FOD damage. I have seen FOD damage before a couple times and it looks completely different.

Its not a 1200 dollar mistake lol. Im probably about to make your day..

Send your turbo out to a rebuilder. Pay 150-200 bucks(Maybe more idk exactly) to get a new turbine shaft/wheel. Pay the balancing fee, and the cost to re ring the shaft. Then your set.

To balance a turbo, you take the shaft and the compressor wheel completely out of the CHRA, the CHRA has nothing to do with the balance of the rotating assembly. They index your compressor, and spin it on a balancer then take a bit of metal out where its needed with the turbine/compressor outside of the CHRA.

But hey if you wanted to just get a new turbo ill take that 'junk' GT-R CHRA off you, 200 sound fair?

I'm not 100% sure what the deal is, but I've heard multiple times that the BB CHRAs can't just be "taken apart" and balanced like a journal bearing turbo. It takes special equipment, and Garrett doesn't give that stuff out, or balance them themselves.

[neech]

Well guys, I found the problem

(CP Pistons btw)


Looks like it was jumping around in there for a bit. Seems as if AGP guy was right.. I would say that's enough metal to frag the turbine wheel.. NOW its a $1200 mistake (and going up)..

Here is the head.



Oh well, shit happens. Such is life when you enjoy fast cars. I have a spare cylinder head that I will build up and maybe I'll sleeve this block since its already at 87mm, or maybe I can find an sr block in town.

At least I have something pretty to look at in the meantime



I have also heard the same thing, that the BB turbos are not the same as the journal bearing, that disassemble is not a simple thing.. In addition, IIRC, ALL GT series turbos are balanced as a complete CHRA, which requires expensive proprietary equipment that Garrett has, and won't give out.

-mike

[S14DB]

How is your tuning?

[Def]

That's detonation damage, not FOD damage. Notice how the combustion chamber is relatively unscathed.

Yes, it looks like something was banging around in there, the flamefront of detonation. When you detonate/get preignition, the combustion is irregular, being much hotter and higher pressure than normal combustion. It ends up leaving "pock marks" where it happens, and tends to break ringlands as you've seen.

The plug looks surprisingly good from that angle given how much detonation you were having.


You need to look at your tuning and check your AFRs. I recommend a wideband O2 sensor being used at all times on highly stressed engines like a relatively high output turbo engine.

[neech]

The tuning was done by a place in the previous owners town, a smaller city here in NM.. They really do more muscle car stuff. I have an AEM wideband installed and the AF's are 11's in boost. I'm gonna have to retune it once i get everything taken care of..

Here is #4, are these the marks you are talking about that are caused by detonation? Or is this fod?



Thanks for the input guys.. This is a lesson to me to never buy a modded car no matter how good of a deal it is!

[S14DB]

Those Pock marks are Detonation. The explosions tear at the metal. FOD looks like someone threw pennies at the pistons.

[FusionR240sx]

what kinda noises was your motor making?

[Def]

How much timing is it running at say 1 bar of boost(~200 kpa absolute) and what's the compression ratio? I'm betting it's something completely unreasonable if you say it was running an AFR of about 11's.

[clark]

holy shit, that makes me wanna cry...

this is probably the least of your problems, but your intercooler is probably clogged with metal chit too.

[S14DB]

Originally Posted by clark

holy shit, that makes me wanna cry...

this is probably the least of your problems, but your intercooler is probably clogged with metal chit too.

How ?

[neech]

Here is the timing, rpm cells are from 500 RPM to 9K. 21 across the board at 14 psi. Who knows what the state of the tune was though when the previous owner had it.




And there isn't any metal in the intercooler. The compressor wheel is mint, that pic is of the turbine.

[Def]

That timing doesn't look that bad, a bit aggressive at 17psi, but still not bad enough to do that IMO.

I'd get your injectors flow tested. If the other cylinders seem fine I'm betting there is an issue with 1 and possibly to a lesser extent 4.

[neech]

Originally Posted by Def

That timing doesn't look that bad, a bit aggressive at 17psi, but still not bad enough to do that IMO.

I'd get your injectors flow tested. If the other cylinders seem fine I'm betting there is an issue with 1 and possibly to a lesser extent 4.

Word, flow testing is what I was thinking as well, there is a place locally that can do it.. Thanks for your help/insight, it's much appreciated.

I would be willing to bet at one point it was a lot more advanced.

[480sx]

Ill take that CHRA off your hands if you dont want it like i said. Send me a PM if your interested.

[240sxspeed]

trust me it doesnt take much that is definatly foreign object damage buddy that sux though if that peice stayed in the housinf 4 10 seconds it would ve did that but if it was 2 step damacge the fins would curl a little then break off