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Discussion Starter #1
Anyone run into this issue with warping the turbine housing? This is my second turbo in my second season, and second turbine housing in which I've warped the housing. The center section (cartridge) will not fit after removal (and had to hammer it out at that).

I run these turbos hard at the track ~650+whp every few weeks. First turbo blew oil seal, and warped housing. Second turbo wore down the thrust bearing, developed axial play, but also warped the housing. I believe these are ductile iron turbine housings, and couldn't find anything stainless.

Turbo is a S300SX3 177272 model (60mm). I'm running standard turbine blanket (need to or I'll fry the paint on my hood!) and a vented hood to boot. I run her rich too.

I'm unable to find anything else that would be an "upgrade". Sadly, I'm replacing turbos every season :(
 

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I had read of a few PTE turbos warping turbine housings, but this is the first time I have read about a BW doing it, although to be fair, road racing, every few weeks, with 650whp isnt going to make any part have an easy life.

I am trying to find out if there are any stainless steel options for the PTE 6266, as I would like to do what I can to avoid the same thing happening to me at some stage.

Have you reached out to BW, and if so, what has their response been?

P.S rather than running a turbo blanket, have you considered making up a heat shield so that it stops the radiant heat damaging your paint on the bonnet, but allows more airflow around the turbine housing? Perhaps running a duct from the front of the car, and running it to near the turbo to increase cool airflow around it could help too.
 

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Discussion Starter #3
Will call BW Monday and discuss. I like your idea of a shield rather than a blanket - will try it out. Not sure about airflow since my vented hood evacuates air OUT of the engine bay ;)

I'm moving from .91AR to 1.00 AR to see if it helps reduce EGTs, and going to richen from 11.8 to 11.2.
 

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I run the same turbo but in the 1.00 a/r for the last 6 years, road race just like you and just recently had the complete turbo pulled apart and inspected with no fault to any component! Biggest difference between our similar set ups is that, you have managed to push this turbo to the horsepower and boost levels i just simply cannot get close to due to Back pressure!!
This turbo needs a bigger Turbine inducer and area volute.
You may need to step up to the 62 or 63 with the 80mm turbine inducer wheel to run that power level at lower boost.
 

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Discussion Starter #5
Theoretically, would going to larger A/R reduce EGTs? I'm assuming EGTs are solely based on mixture, and backpressure between head and turbine don't affect it at all.
 

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Yes, it does affect EGT's. Its common to see a drop in them when going to a larger A/R turbine housing, as it reduces back pressure, and stops a small amount of burnt exhuast gasses getting pulled back into the combustion chamber.
 

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Good question! and yes, it certainly is a contributing factor. It usually high lights an exhaust restriction at the turbine compressor wheel / a/r housing side of the exhaust system on turbo engines and its best to be measured at the center of the exhaust manifold. I would also give consideration to not run the AFR's richer as high back pressure can depending on the engine cause changes to the AFR's usually enrichment.
This turbo is rated at 320 to 800hp application but not on our engines or any 3.0 inline 6 combo such as an rb25/30. 500 - 600 rwhp absolute max on any flex fuel combo with boost hitting at around 22psi and bleeding back to 18 to 19 psi regardless of wastegate size or quantity!, full twinscroll setup etc!!
Anyone who has taken apart a BW journal bearing turbo internals compared to other makes knows just how durable and stout they are. Designed to run for sustained miles on end at boost when sized correctly!
No turbo will last beyond its capabilities, especially the environment and sustained levels your putting this through. Going to a 1.00a/r long term is not going to help. You need at least a 1.25 a/r which is custom built utilizing the same turbine wheel at your boost level or step up to a larger turbo that can produce your horses you want at lower boost pressures.
 

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Discussion Starter #8
Good points. I'm hesitant on going larger since the response and power are perfect for the track! Going richer is the only thing I can think of to reduce EGTs at this point, and I'm only talking a few points. I'm also going to increase my water/meth injection.

I know these turbos are stout, but I honestly don' t know of many running these in competition (I'm not talking highway pulls or 10sec 1/4mile stints). Been doing some reading and it seems RX7 guys who compete/roadcoarse also have these issues.

It's insane to see the droop of the turbine. Even the center divider of the divided inlet drooped! I'm melting metal here ;) I'm also going to stop using the heat blanket and move to a heat shield to allow additional heat to escape the housing. Being that the weather is now cooling, I may have to wait another season to see if any of this has benefits.
 

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What size is your down pipe? And what manifold design are you running? WG size?

Anything you can do to reduce back pressure will help, but from what you just said about the turbine housing metal actually drooping, it sounds like something is seriously amiss.

Are those turbos designed to be run on diesel engines, or petrol too?

Some more water/meth should help, but I think you might need to log your back pressure, and your EGTs so you have some concrete data to work with moving forward.
 

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Discussion Starter #10
3.5" exhaust straight through. RPS manifold, 46mm Tial. I don't think there is much backpressure post-turbine.
These turbos are listed as John Deere turbos ;) Tractors?

I have been running meth/water all this time, but it seems to not be enough. I run it up to 8k constantly as well, it holds 24psi up to the top.

Will see if these small changes improve. I have an event next month.
 

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Going to a 4" DP will still reduce BP, so if you cant get to the bottom of what is causing this problem, then doing all you can to reduce BP will be your only course of action.

Have you looked into finding other turbine housing options apart from a stainless option you mentoned? If there is no easy swap option, I would suggesting that along with a 4" DP, moving up to a larger A/R housing will help, and even though you have mentioned that you dont really want to do that as you will lose response, the amount you will lose will hopefully be negligible, given you will generally always be revving the motor atleast high enough to stay in boost.

Yes John Deere are diesel tractors, so its possible that the metal that the turbine housing is made from isnt designed to cope with the sustained extreme heat that your high reving petrol engine is creating

Out of interest, does the turbine blade itself stay in shape? And what is the cooling system coping like? Are your oil and coolant temps acceptable?
 

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Discussion Starter #12
Can't fit 4", there is no room at all. I tried. I need the response for corner exit, I'm sometimes at 4000rpm at the apex and she makes good torque down low.

Turbine blade stays in good shape. Coolant peaks at 210, oil peaks at 260. Both drop (19x / 24x) if I do a single lap at 6/10ths. I think cooling is Ok.

I did upgrade to 360deg thrust bearing and some better flowing shaft bearings, will see how that goes in a month. 4an oil feed line (no restrictor) was checked, flows well. Drain line is 10an, flows well, straight down. Can't think of anything else that could contribute...
 

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Im presuming you have a reasonably sized oil cooler core? Is there any way you can run your turbo oil feed from the cold side of the oil cooler, in order to send the turbo cooler oil?

im just trying to think of small things you can do to try and reduce temps.
 

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Discussion Starter #15
RPS shouldn't be an issue, I can control boost just fine. I had the same issue with a SupraStore tubular manifold last year before I made the swap.

The issue with downpipe is I don't have enough room underneath the car for anything larger than 3.5". Forgot to mention, this is the Z4 (not the Supra), but 2JZ regardless, shouldn't matter.

Oil cooler is super huge. CSF unit https://www.amazon.com/CSF-8032-Race-Spec-Cooler/dp/B01DXXD72I

Interesting idea on feeding turbo cooler oil directly from cooler. It's being fed from the standard area from the block near the tstat - I don't remember how far down the chain that would be though. 260 peak isn't necessarily bad, I usually don't hit it, mostly 240-250.
 

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Xona Rotor has turbos that would be an upgrade.
Not just Xona, Garrett too. In case you've never looked at the turbine maps for BW, they are NOT designed for high rpm use on those old models. They really fall off up top as everyone knows. A larger A/R would help but 8k is still too much on an inefficient turbine. Precision doesn't show maps but they have extremely efficient compressor wheels. Garrett you can search up on their website. A new 60mm from then would flow more with lower intake temps and smaller turbo frame size. And you won't be only oil cooled on old style bearings. Basically im recommending an upgrade over a 15 yr old turbo:/ They aren't bad but the base ones definitely aren't the best either
 

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My guess is you have a 74mm turbine with the .91 twin scroll? So you're 6 up from the bottom here. It's for quick response which you have but over 6k RPM it can't breath. Probably why you need meth to keep it going up top. It just can't get all the heat out effectively while your pumping all that air/meth mix back in. Turbines are major restrictions for the S360 series. Remember temperature increases with pressure and you probably have a heck of a lot of back pressure any time you keep those revs high. So if your back pressure is 3:1 you're creating a lot of excess heat. Probably over 1600 degrees F consistently. That will melt a lot if kept up, the turbine rating is 1,800 degrees or so and 1,970 for the wheel itself (for 5 to 10 seconds) before metal fatigue occurs.
 

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Discussion Starter #19
The s300SX3 is 60mm inducer dia, 68mm exducer diameter (76mm turbine wheel OD), and a .91 a/r housing. You can see the last dyno at less boost (22psi), but the turbo seems to handle all the way to 8500rpm. I only use the meth/water to supplement 93 pump since I don't run race fuel.

I'll look into Garrett as well, thanks!
 

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Upping the boost will give you more midrange but the torque drops off up top still instead of staying steady to redline. Power is still there which is great but the turbine is an issue regardless.
 
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