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Old 10-26-2012, 12:04 PM   #26
phucheneh
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Quote:
Originally Posted by jlee View Post
A ball bearing turbo..
Maybe if you believe the youtube videos where some guy spins an oil-less journal bearing with his finger, then compares it to a ball bearing.

OMG LOOK HOW MUCH MORE AWESOME THE BALL BEARING IS.
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Old 10-26-2012, 03:59 PM   #27
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Quote:
Originally Posted by phucheneh View Post
Maybe if you believe the youtube videos where some guy spins an oil-less journal bearing with his finger, then compares it to a ball bearing.

OMG LOOK HOW MUCH MORE AWESOME THE BALL BEARING IS.
Erm... JLee has first-hand experience with ball-bearing turbos and what they do. You'd do well to heed his advice.

Other options with a T3/T4 turbo to maintain power and improve spool is to keep the same exhaust housing an install a bigger compressor housing and wheel. If there are any options for cold air induction, optimize the IC plumbing, or increase exhaust breathing that will help too.
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Old 10-26-2012, 04:11 PM   #28
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I know the general theory (though I freely admit to not being any kind of authority on the matter). The reason I'm going to use that BW turbo is because it has a pretty huge compressor wheel vs. a fairly efficient turbine setup. And again, the compressor map seems to fit well; at the given boost level and expected power output/fuel consumption, it should be near peak efficiency.

I just think ball bearings are overrated. I'm not against newer turbo design (that BW is pretty refined)- I'm just not a proponent of aftermarket ball bearing turbos given the current situation. Essentially, the combination of much greater expense with a lack of rebuild options just does not make them an attractive option. Yes, I'm sure they spool up faster, but how much faster still seems to be a topic of debate (in this application, I think a 500rpm difference would be optimistic).

The positives just do not outweigh the current negatives, IMO. I know that's a big generalization, but at least you know the position I'm generalizing from (Re: the vehicle I've described here).

edit: oh, and I corrected myself later in the thread- it's not T3/T4. T67 is a straight T4 variant, and the replacement turbo has a T4 inlet.

Last edited by phucheneh; 10-26-2012 at 04:15 PM.
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Old 11-08-2012, 12:25 AM   #29
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Sooooo....update:

Finally got some parts in for this and have done most of the disassembly as well as some other needed tweaking. Found a couple surprises.

The Garrett name is indeed cast into the turbine housing. But nowhere else. There was no tag on the center section.

The turbo has even more shaft play once you take the compressor housing off...apparently it was limited by compressor wheel contacting the housing.

Cause of bearing death was oil starvation. I think the feed was partially plugged...not that it would matter, as the inlet restrictor they used is approximately the size of a pin. Like, the kind that comes stuck in a folded dress shirt. I know ball bearings are supposed to have restrictors, but...really? That could not have done anything but supply a constant supply of oil...droplets. Also, I thought the oil return that consisted of a pipe immediately taking a 90* turn then connecting to a rubber hose with worm clamps was pretty sweet.

The reason I actually got called was not because of the oiling issue/horrendous racket from the turbo. The lack of boost was primarily caused by a stuck-open wastegate.

Why was it stuck? A giant chunk of slag was jammed in it. It broke off the inside of the exhaust manifold (tubular/header style). The turbine probably didn't enjoy that, but I don't see any damage, which is mind-boggling. I haven't looked at the inducer portion yet, due to the bolts for the turbine housing being seized like a motherfucker. Perhaps the piece miraculously fell sraight down into the wastegate instead of going through the turbo.

I had thought the manifold was a quality piece. The exterior welds look good, and it's of what I would consider the preferable design- 1-3 and 3-6 cylinders are divorced for split inlet turbos. One pipe from each side leads to wastegate.

...key point, the EXTERIOR welds look good. The interior looks like Helen Keller went at it with a 110v Harbor Freight arc welder. While drunk.

Pics to come.
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Old 11-08-2012, 02:20 AM   #30
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Better view of 'T67' inlet.



This is what was jammed in the wastegate. Not carbon; steel.



The manifold...looks okay enough, right?



Nope. p.s. - hard to focus inside a black manifold- believe me, it's awful in there. It is pretty obvious that the slag broke off the right side.



New versus old







That funny ID plate thingy that most legit turbos seem to have:



Old oil inlet fitting.


Last edited by phucheneh; 11-08-2012 at 02:24 AM.
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Old 11-08-2012, 07:38 AM   #31
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That's why you pay a big more $$ to have a TIG-welded exhaust manifold, I've seen short lengths of MIG wire poke through welds even.

From Garrett regarding restriction sizing: http://www.turbobygarrett.com/turbobygarrett/faq

"Q. Does my turbo require an oil restrictor?
A. Oil requirements depend on the turbo's bearing system type. Garrett has two types of bearing systems; traditional journal bearing; and ball bearing. The journal bearing system in a turbo functions very similarly to the rod or crank bearings in an engine. These bearings require enough oil pressure to keep the components separated by a hydrodynamic film. If the oil pressure is too low, the metal components will come in contact causing premature wear and ultimately failure. If the oil pressure is too high, leakage may occur from the turbocharger seals. With that as background, an oil restrictor is generally not needed for a journal-bearing turbocharger except for those applications with oil-pressure-induced seal leakage. Remember to address all other potential causes of leakage first (e.g., inadequate/improper oil drain out of the turbocharger, excessive crankcase pressure, turbocharger past its useful service life, etc.) and use a restrictor as a last resort. Garrett distributors can tell you the recommended range of acceptable oil pressures for your particular turbo. Restrictor size will always depend on how much oil pressure your engine is generating-there is no single restrictor size suited for all engines. Ball-bearing turbochargers can benefit from the addition of an oil restrictor, as most engines deliver more pressure than a ball bearing turbo requires. The benefit is seen in improved boost response due to less windage of oil in the bearing. In addition, lower oil flow further reduces the risk of oil leakage compared to journal-bearing turbochargers. Oil pressure entering a ball-bearing turbocharger needs to be between 40 psi and 45 psi at the maximum engine operating speed. For many common passenger vehicle engines, this generally translates into a restrictor with a minimum of 0.040" diameter orifice upstream of the oil inlet on the turbocharger center section. Again, it is imperative that the restrictor be sized according to the oil pressure characteristics of the engine to which the turbo is attached. Always verify that the appropriate oil pressure is reaching the turbo. The use of an oil restrictor can (but not always) help ensure that you have the proper oil flow/pressure entering the turbocharger, as well as extract the maximum performance." (emphasis mine)

Interesting... maybe the turbo failed from oil starvation.
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Old 11-08-2012, 11:58 AM   #32
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40 thousandths is a little more than a millimeter...I'm not sure if that hole is even that big. Would have to find something to jam in it then mic it, heh.

What does 'minimum' mean to them, though? Numerically minimum (.040+) or minimum restriction (.040 or less)?

Just seems like a bad idea for a street car...good grief, an errant mosquito turd in your oil could plug the above fitting.

I was looking around at manifolds...it's an odd market. Either you pay a grand or more for one that's probabably TIG'd by Jesus, or you pay a couple hundred, tops, for one full of slag. I think I'm just gonna wash the carbon out of that one, and bust out the dremel extension to get in there and smooth things out. Worst case, I make a little hole that needs to get welded up [properly]. Not a big deal since I'm going to have to chop up the downpipe and take it to a fab shop to get rewelded, anyway.
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Old 11-08-2012, 01:40 PM   #33
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Quote:
Originally Posted by phucheneh View Post
40 thousandths is a little more than a millimeter...I'm not sure if that hole is even that big. Would have to find something to jam in it then mic it, heh.
Small number drill bit set #61-80 is what I used to use to measure the small stuff along with my normal number, letter, nominal size drills. I think I bought a set 30 years ago for $5

http://www.amazon.com/20pc-MICRO-DRILL-INDEX-61-80-Plastic/dp/B000TY190C

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Old 11-08-2012, 02:13 PM   #34
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Thanks for the tip; that's a good idea that I will definitely use if I need to measure something small in the future.

In this case, it's pretty much moot, as the new turbo is journal bearing and should not require a restrictor. The inlet fitting is basically enough, assuming your drain is properly sized and your oil pressure isn't super-duper high. If I do find it needs a little more restriction, it's no big deal; better to have to fix over-oiling as opposed to under.

I'm running a -4AN feed off of what is supposed to be the optimal point on converted 2JZGE's (oil pressure sender located near pan). -10AN (5/8") return. Should be good to go.
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Old 11-08-2012, 04:12 PM   #35
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Good luck!
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Old 11-08-2012, 05:05 PM   #36
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Testy fittin'.

Grr.



Ignore jumble of crap. It'll get sorted through.



Oh, and zip ties are not the permanent mounting for the ABS controls. I was just seeing if I could move the mounting a bit and not have to bend any new lines.

Also that IC piping is going to be a bit of a whore. Would be much easier if Borg woulda put a 2.5" outlet on there...that extra half inch makes piping mammoth. It'll fit, though; just barely. Oil drain is also problematic, hence the dumb shit that was on there. But I think I can cant the outlet just a bit to the left and run it right behind the charge outlet.

Last edited by phucheneh; 11-08-2012 at 05:09 PM.
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Old 03-13-2013, 01:04 AM   #37
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So...been a while on this. I wanted to post an update, 'cause even though it's not my car, this thing is pretty interesting.

It's still running on the old tune right now. I've got my own written that I'm going to put on it and then start tweaking (the current one is 'locked' and cannot be retrieved and modified- sucks).

I'll take some video and put it up later this week. This thing is fucking nuts. It feels like a fairly average ~200hp car if you cruise at 2000-2500rpm. Maybe closer to 300 (butt dyno!) by the time you hit 3000 or so...but at 3000 it's starting to whistle something awful...

Then, at some point very briefly past that (I don't know when...it's hard to watch the tach when you're trying not to die), it goes to 'holy shit, the Fast and the Furious was accurate after all' mode. The whine is replaced with the sound of rushing air the likes of which I've never heard before. And at or near WOT, the engine accelerates so quickly from <4000 to >6000rpm that you can barely even react to it.

Tires break loose in third. Not 'break loose when subjected to shift shock,' mind you. You can start third at 2000rpm and the tires break loose from the sudden, violent turbo spool. As an outsider reading this, I would think this is shitty, and say the engine is far too peaky. But it's really not. If the power came on any sooner, you'd friggin' die. It would be fairly potent NA (a 2JZ with cams and an unrestricted intake/exhaust is probably stout enough for most), but good god, the turbo is like a 200+hp shot of nitrous.

It really does remind of those retarded F&F scenes where they hit a button and the car suddenly grows an invisible rocket engine, revs like the engine is in neutral, and goes like a meatloaf out of hell.

Cliffs: I highly recommend BW turbos. Fuck Garrett. This thing is a goddamn monster. For ~$700.
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Old 03-13-2013, 04:33 AM   #38
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Video or ban
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Old 03-13-2013, 07:09 AM   #39
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Video or ban
This!
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Old 03-13-2013, 03:23 PM   #40
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I'll see if I can get a shitty phone video today...I'm going to go see why the BOV doesn't appear to be opening properly, causing it to randomly shit intercooler pipes. The valve is plumbed into the same spot it used to be. But I never saw the car actually make boost with the previous setup (dying turbo and stuck-upon wastegate), so maybe the damn thing's just never worked right.

To anyone who's built/researched/fooled with aftermarket turbo stuff- is there any reason people like to point BOV's forward? Does it make the noise more appealing or something?

I see it a lot, and this is mounted like that (flared outlet dumping forward, exposed to frontal airflow). I meant to rotate it to the side if I could, as ram-air into the the outlet seems like it would be counterproductive. I'm just curious as to why anyone would NOT think the current orientation is a bad idea.

It also might just need a different vacuum source.
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Old 03-13-2013, 07:28 PM   #41
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I love those older IS300s. Great sleeper car. Makes me want to turbo my wife's IS250.
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Old 03-13-2013, 07:30 PM   #42
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Did not get video. Was just me driving...no freakin' way I'm getting video without a second person in the car.

The BOV is fixed...it was stuck. D'oh. Diaphragm inside is worn, which was both keeping it from opening very much, and causing it to stick just barely open. The vac line to it was using the same source as the boost gauge, which I think is managing the wastegate solenoid. Not positive; the gauge can do it on its own, or the ECU can do it. Haven't checked the wiring.

Anyhow, sprayed diaphragm with silicone as temp fix. Now the gauge is actually working right, too. Hooray. Wastegate is dumping at 22psi. No problems with pump gas. I am feeling pretty certain that it is over 500rwhp. I've only ever felt 300-400, so it's hard to make a guess that is more definite than 'a lot more than that.'

...also this might get some nitrous. Just a wee bit...
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Old 03-13-2013, 07:41 PM   #43
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Quote:
Originally Posted by JulesMaximus View Post
I love those older IS300s. Great sleeper car. Makes me want to turbo my wife's IS250.
Yeah, it's a nice-looking car, and aside from the really big intercooler, I don't think many people would suspect it is what it is. Just an older IS with some typical mods (lowered, wheels, body kit). And a loud muffler.

Really loud muffler. It's funny...I kept having fitment issues with the downpipe...every time I tweaked something, it wouldn't line up. Just no room for error between the turbo outlet and wastegate connection. So...the wastegate is currently...dumping to atmosphere. Which means there's also a slight leak in the exhaust. I'm gonna just call it a 'speed hole'...

The point, though? The exhaust dumping out a few feet from the turbo is like the same volume as what's coming out of the 'muffler.' Heh. I think we're gonna replace it and maybe add second muffler ('resonator' if you will) in the middle of the exhaust.
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Old 03-13-2013, 08:19 PM   #44
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Really nice work man! Any more power those tires are gonna scream and run home for daddy first outing.
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Old 03-13-2013, 09:44 PM   #45
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It's got a fairly big set of KDW's on it. 245's, maybe? It actually may have room for more in the back. Fronts are rubbing 'cause I kind of dicked with the coilovers (...people shouldn't ask me open-ended questions like 'can it go lower?'). The stance looks great, but it's got spacers on the front to clear some aftermarket Brembo stuff. That's the root of the rubbing issue. It really just needs wheels with a more carefully chosen offset.

However, I think tires are overall kind of moot. Anything less than stickies might as well be bias plys.

It also has one part that I honestly just don't know dick about- Race Logic add-on traction control. It does not appear to help...
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Old 03-14-2013, 07:56 AM   #46
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I'm sure you could pick a DOT legal tire that'd get that power down, at least on warm days

Also, the wastegate dumping to atmosphere pre-cat (if you even have a cat) will do a great job of corroding anything downstream. Ask me how I know...
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Old 03-15-2013, 11:56 AM   #47
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The BOV's are usually oriented forward because they would recirculate in to the intake.
I have a 99gsx (turbo AWD) that I have done a lot of work to.

Some turbo cars ECU is counting on the air released from the BOV(when you let off the gas in boost) to be reused. Without recirculating, the AFR would be more rich that it is supposed to be.

If you are not recirculating, it does not matter what direction the BOV is facing, since it will only open when it needs to.

Also, your boost gauge should not be getting it's reading from the same vac line that the BOV is using. It should be T'd from the vac line from the intake manifold, atleast, that is how it is supposed to be on an eclipse.
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Old 03-15-2013, 05:18 PM   #48
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Why would orientation matter if you're recirculating? Also, isn't that usually called a 'bypass valve' rather than 'blowoff'? Kind like open wastegate versus one plumbed back into the exhaust? (BTW, JCH, it's just temporary until I pull the downpipe and give it a little slice and re-weld action to get it fitting right)

The BOV and boost gauge are on a T going into the same vacuum nipple in the intake. It's right before the individual intake runners start (but still well behind the throttle). See engine bay pic:



Behind the P/S reservoir. There's a hose going right, toward boost gauge. Hose going left to a pipe, when travels to other side of engine and then has a hose to BOV. I don't see this setup as a problem unless the fitting in the intake is small enough to create a notable restriction to airflow...which, come to think of it...maybe it is. There's probably a lag in the pressure change at the BOV because of the extra volume of air in the hose to the boost gauge. Also, I need to find out with certainty which area of the intake goes to vacuum the quickest. Part of me want to say "right behind the throttle plate" and another things it would be closer to the intake valves...I don't grasp fluid dynamics enough to be able to understand exactly what happens when the throttle snaps shut, I think.

Here's the BOV on this:



Obviously it's directly exposed to the velocity of the air coming into the front of the car (or the car slamming into the stationary air; no reference frame debates please). I don't know how strong this actually can be in comparison to atmospheric pressure + 22lbs in the intake. But it's an extra, constantly-varying force that I would think affects the BOV's opening.

I mean, you've got the pressure of the intake charge against the face of the valve, opposing the amount of vacuum/boost in the intake (and spring pressure). You're relying most specifically on the pressure differential between the charge pipe (quickly building when the throttle closes) and the intake (quickly turning to vacuum when the throttle closes). But the orientation adds another force- air being shoved against the rear of the valve, essentially becoming a speed-sensitive increase in BOV spring pressure.

I'll be honest in saying that I have a hard time 100% grasping the principles of BOV 'tuning.' As in, adjusting the spring pressure so that the valve opens at a desired boost level...I mean, shouldn't it, ideally, be able to operate independent of the amount of boost? As in, all it should care about is the differential between intake pressure and charge pipe pressure...seems like it should be as simple as 'if intake switches from boost to vacuum, purge charge pipe.'
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Old 03-15-2013, 05:36 PM   #49
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Also, random opinion request from JCH or other turbo guys:

With a turbo that big, how much do you reckon intake volume matters? This setup spools faster than the T67, using old dyno sheets as a mark for comparison. But it still has some obvious delay...which, as mentioned, I like for the side-effect of not throwing the car sideways into a ditch on accident. But you could argue that the insanely-violent spool might be just as dangerous.

I mentioned possibly adding some nitrous to help spool. But I think a significant shortening of the IC piping could also do a lot...but I'm not certain. I think, somewhat paradoxically, that with a SMALL turbo, it might do a lot; the small turbo having a much harder time shoving enough air to fill the large amount of space. This one, in comparison, can move crazy quantities of air, and once it hits the sweet spot...my god.

I guess the question is whether or not that sweet spot would actually come in sooner or more gradually with a drastic reduction of charge piping. This is possible because of the existence of 2JZ intakes that keep the throttle on the driver's side of the engine bay...not only does it make the intercooler>throttle pipe shorter (and avoid the clearance issues you can see in above pic), it removes an entire section of piping that must travel to the opposite side of the car and enter the intercooler on the side opposite the throttle (then the intercooler moves it right back in the other direction).
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Old 03-16-2013, 03:42 PM   #50
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Quote:
Originally Posted by phucheneh View Post


I'll be honest in saying that I have a hard time 100% grasping the principles of BOV 'tuning.' As in, adjusting the spring pressure so that the valve opens at a desired boost level...I mean, shouldn't it, ideally, be able to operate independent of the amount of boost? As in, all it should care about is the differential between intake pressure and charge pipe pressure...seems like it should be as simple as 'if intake switches from boost to vacuum, purge charge pipe.'
The BOV doesn't open at a desired boost level. It opens when you let off the gas, IE, when you CLOSE the throttle plate. The condensed air needs somewhere to go, so the BOV opens to let it out. If it doesn't get let out it will expand and go back towards the turbo, causing problems.

The only thing that opens at a certain PSI is the wastegate. This is so you can keep a steady, specific, PSI.
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