Oil restrictions / larger drains for journal bearing twin turbos

Discussion in 'N54' started by MMP, Feb 6, 2018.

  1. dyezak

    dyezak Lieutenant

    762
    Plano TX
    335is
    I should go pull up the discussions by ForcedPerformance from the late 1990’s when they explained this very problem with Mitsubishi TD04 housing hybrids. I think it was on DSMTalk.com.

    And btw, you would regularly see enough crankcase pressure in a mildly modified 4g63 to blow the dipstick out, and if the turbo feed and drain were the upgraded buschur/FP/extreme version you never had a seal problem.

    This is real as are other well known quirks with Mitsubishi based turbos. Sad thing is MMP is only a 4hr drive from FP. Easy day trip to have a sit down and learn all this shit first hand without having to use customers as test subjects while rediscovering things that have been well documented for over 20y.
     
  2. Tippin

    Tippin Specialist

    67
    If you are seeing positive crankcase pressure then is that really a turbo problem? I personally run my car VTA with andys fittings which he claims to have measured zero crankcase pressure.

    I agree with you 100% that crankcase pressure is a variable but then that should be the focal point before you blame a turbo for not draining properly.
     
  3. Rob@RBTurbo

    [email protected] Specialist Vendor

    71
    Personally I think Tippin is giving a bit more credit than he should here regarding "data" on this topic. The only data that has been presented (of which we've also witnessed a million times on our VSR) is that visually the amount of flow doesn't seem to be much to warrant a larger drain diameter than that of OEM. On this topic however consider the following:
    1) Under full load the oil becomes very frothy and thus the volume increases which causes slower draining. Full load (max RPM's) on a VSR is a couple seconds, whereas on a car it usually is much longer. This is also in the absence of any other variables as pointed out above by mikeseli and is viewing a perfect 6 o'clock drain function with no oddly bent lines, amongst other variables as in vehicle inertial forces or angles/oil levels/etc. and a drain into a perfectly open atmosphere.
    2) The N54 engine sits in its cradle at approximately a 30* angle (leaning towards the turbo side). This puts the turbo itself only a couple/few inches above the engine block return provision and also a drain outlet which is at a submerged level into the oil pan (pending on oil level) which can affect draining as typically it is suggested to drain above engine oil level.
    3) We have disassembled approximately 2,000 N54 turbos to date (since 2009), and have found that the vast majority have oiling conditions are found on the front turbo as opposed to the rear turbo (see #4).
    4) Both are obviously bottom mount turbos however the front turbo is positioned quite a bit lower/tighter to the block than the rear. This means the front drain has less of a decline meaning less gravitational assistance than that of the rear. Compound this with a near horizontal (plane to ground) front outlet (as to bend around the water pump plumbing) and draining is certainly further impeded (see picture attached). The rear turbo drain is a much better design (although still has the smaller ID), plus it is further from block/up for better gravitational assistance.
    5) Even if all were perfect with the routing the OEM drains are undersized, not just subjectively stated by RB (or any other vendor), but from all of the big dogs such as Garrett and MHI (see post #23 in link here for docs: http://www.n54tech.com/forums/showthread.php?t=33394)

    In short there are a ton of variables even outside kinks and/or any other degradation that the OEM lines could certainly illustrate the OEM lines are barely sufficient. More so it is clear the RB High Flow drains are designed more by the guidelines of the large manufacturers (ie. MHI and Garrett) than the OEM units and they will allow the turbos to drain as best they can within the real estate the turbos are presented. Also consider that if the OEM drains do allow poor draining over time (which we do tend to believe they do based on #2 above on basic OEM turbos) the turbo will degrade as the oil will backup/ seep onto turbine shield/turbine itself, and affect its rotational abilities and of course the CHRA's balance. At the end of the day the best drain (size and design within limits) is better than a "should be ok" drain all day every day throughout time, this should be common logic; but at the same time the healthy OEM drains aren't going to destroy a properly built JB turbocharger in a matter of moments either... they simply are not as ideal.

    Rob
     

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    Last edited: Feb 8, 2018
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  4. BMWE92_Harry

    BMWE92_Harry Private

    47
    N54 E92
    If the turbo is smoking due to improper oil drain, would the smoking issue only occur during deceleration?
     
  5. dyezak

    dyezak Lieutenant

    762
    Plano TX
    335is
    4g63's were snotty leaky ass engines in relation to positive crankcase pressure. But you missed the entire point of my post.

    All these "discoveries" have been known for years. These facts have been known, proven, and solutions developed over 20y ago. Remember, the TD03/TD04 design is an archaic design from Mitsubishi Heavy Industries. These discussions were happening before half our current owners were even alive.

    The fact that vendors are coming forward now and saying "look at what I just figured out" (20y late) means they really had no clue to begin with. If they were interested in performance turbocharger design centered around the TD03/TD04 CHRA they would have talked with people who have been doing this for 20y in a different platform. ForcedPerformance is notorious for being open, sharing, and honest with people.
     
  6. Rob@RBTurbo

    [email protected] Specialist Vendor

    71
    It is an old convo indeed... earliest recollection here was circa 2001-2002 when a larger 3S/6G72 Vendor came out with custom oil drains and they looked sweet but were actually -8AN sized while the OEM drains were closer to -12AN (14.5mm)! Long story short most turbos who ran those drains ended up becoming smokers and these offerings were later discontinued. Keep in mind these were TD04 based turbos as well so it is a perfect analogy; although these had really long drains and were much higher mounted turbos (which helps draining). This made it clear that -8AN will NOT cut it, and the documents from the large manufactures all tend to agree on this.

    Now as these N54 Oil drains are right around "-9AN" (-10AN at their best areas) along with the turbos really low positioning (and poor routing) puts them into a gray area of not being ideal IMO, but they do work and we sell a lot of turbos without them that no one has complained about issues with them. However this doesn't mean that they are best option, only that they are suitable and like the OEM turbos we've seen over the years we bet will take some toll in time. If only we had the instant gratification of knowing the future real time, but we do not and these things can take years to manifest themselves. At any rate this is where the option to upgrade comes in, it is up to the consumer to go that pathway or not. As our RB High Flow drains are closer to -12AN when it comes to ID and are routed better (for flow), they clearly are a step in the right direction.

    Rob
     
    Last edited: Feb 8, 2018
  7. dyezak

    dyezak Lieutenant

    762
    Plano TX
    335is
    Rob gets it. And has the historical understanding. None of this is new, and if a vendor thinks they just discovered this and it's something new it should make you question that vendor's underlying knowledge.
     
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  8. Tippin

    Tippin Specialist

    67
    Would you mind sharing where this -9an section is? because I have yet to find any reduction in ID. I will gladly cut my old ones again.
     
  9. Rob@RBTurbo

    [email protected] Specialist Vendor

    71
    Check out a bit downstream of the turbo side on the front drain... dicing it will be necessary.
     
  10. langsbr

    langsbr Corporal

    189
    07 335i 6MT e90
    If I'm reading the insinuations you are making, it sounds like you're saying MMP just discovered this and you are saying to question their knowledge. I read Mauricio's initial post with a different intent. Just as Rob said that OEM lines are adequate, but he offers improved ones, Mauricio appeared, at least to me, to initiate the discussion on it, as we so quickly learned another vendor came in and wanted to kill the discussion before it started. Mauricio's initial post even mentioned the DSM world, so it doesn't appear to be a discovery - more a "revisiting" of a topic that is not often discussed here.
     
  11. dyezak

    dyezak Lieutenant

    762
    Plano TX
    335is
    Yea....he is just talking about this today after he discovered this. BTW, these restrictors exist, as do the upgraded drains.

    But pointing someone to another vendor's existing product that's been proven to work doesn't allow you to claim you innovated the platform, figured out some mystery first, and blah blah. The whole post strikes me as a "look at how smart I am figuring all this out first" type of post.

    If he credited anyone else that had done this research first, and provided existing solutions....but explained why his ideas were better....then I'd be in agreement with @langsbr. As it stands however....not buying into it.
     
  12. Tony@VargasTurboTech

    [email protected] Lieutenant Vendor

    Can someone please explain how crankcase pressure is a turbo drain problem? If you have crankcase pressure causing a stock -10 size line to back up. Instead of solving the pressure problem, you want to spend $225 on drains that are 1.3mm bigger to solve it? This platform is stubborn, and honestly thinks its discovering things that are just basic turbocharging principles for 30+ years. If you have crankcase pressure that is NOT a drain problem, if you have poorly build CHRA's that cause oil to leak past the piston ring, that is NOT a drain problem. If you have a pinched drain from either poor installation or any other number of reasons, that is NOT a drain problem. The stock drains are plenty big enough for these turbos, made of Stainless steel inside, and out, and will never corrode, or degrade from contact with oil. Anyone telling you different is either A. Trying to make money off bigger drains, or B. Had an underlying problem and managed to patch it with a bigger drain so they are fooled into thinking the drain solved it.

    What some people are doing: Sir I cut my leg really badly, this bandage is filing up so fast, it's leaking out. I see the problem here! Your bandage is too small, put this extra special HIGH FLOW bandage on it, the blood won't leak out anymore! FIXED!

    What people who know turbochargers do: Sir I cut my leg really badly, this bandage is filing up so fast, It's leaking out. I see the problem here! You cut your leg and its bleeding. Let's fix the cut, and the blood won't leak out anymore! FIXED!
     
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  13. Tony@VargasTurboTech

    [email protected] Lieutenant Vendor

    Looks like a lot of people here still believe larger drains would be beneficial, even though research shows they do not help on properly working N54 turbos, and engines. Soon as they are finished, we will offer high flow drains as an option on our turbos, and by themselves for $99.
     
    Last edited: Feb 12, 2018 at 9:42 AM
  14. Rob@RBTurbo

    [email protected] Specialist Vendor

    71
    Good deal sir and glad to see you come around. Will go great with your ever growing collection of Cheap chinese turbos and piece parts.:wink:

    Rob
     
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  15. veer90

    veer90 Corporal

    121
    Rye, NY
    e90 335i 6MT
    Last I checked those rings are designed to stop exhaust gases from entering the CHRA, not designed to contain oil in a poorly draining CHRA.
     
  16. Tony@VargasTurboTech

    [email protected] Lieutenant Vendor

    DING DING DING, the piston ring is a non positive seal, it will not stop oil. As soon as the oil level reaches the piston ring, it will begin leaking past it. I made a video today of how little oil actually comes out of a properly built N54 CHRA at 40 psi, and 100 psi of oil pressure. When I get around to it, I will post it. Honestly, this topic is more a joke that everyone has taken seriously. Fix the root problem, not the by-product of the root problem...
     
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  17. Torgus

    Torgus Corporal

    Tony, so if they do not help, and you honestly believe that, why offer them? It only takes away from your credibility which is...well...you know ;) #metoo #pussyhats

    Then again, I don't believe drilling out the factory fuel line will help but you happily took customer's money for that as a hpfp upgrade. So I guess that fits in with your line of thinking.

    How is your wife's class action lawsuit against RB going again? Seriously?

    Lawls
     
    Last edited: Feb 13, 2018 at 6:02 AM
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  18. mfractal

    mfractal Lurker

    10
    E90 Sedan LCI 335i FBO MHD E40
    bipolar much, Tony ? Instead of focusing on the "useless" part as you claim, why not go warranty the 150 defective turbos of yours ?
    My sentiments exatly!

    He should stfu and go take care of his what, 150 recent faulty turbos, or was it more... instead, he interrupts grown up conversations. Nobody with a brain takes him seriously anyway.
     
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  19. Rob@RBTurbo

    [email protected] Specialist Vendor

    71
    Guess to summarize this great discussion for the OP:

    High flow oil drains are not absolutely required and your turbos will not die (or smoke) immediately if you do not use them, assuming you are comparing to otherwise healthy OEM drain lines. But they make sense to use when/where possible and over the longterm likely will show larger benefits- it certainly never hurts to have superior drains.

    Rob
     
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  20. MMP

    MMP Lurker Vendor

    Generally some good discussion going on. Thanks for the turbos suppliers for contributing and also for the members. Rob thanks for your comments and even you Tony although you cant help yourself and throw out some underhanded digs about my CHRAs being defective somehow, nice, yet you make perfect turbo that never fail right....hmmmm. How about we leave the personal and product digs out of it and stick to the discussion, huh?

    I still stand by my original statements. first thing you should do is make sure that your crank case vent under boost and also under vacuum is setup and working correctly and venting free flowingly out of the valve cover. Once that is done make sure your oil drains are large enough, unrestricted, and not the problem. If both those things have been tackled and still have smoke and turbos are perfect, then last step is restrict the oil pressure. 1.5mm - 2mm restrictor is a good suggestion to reduce the oil pressure based on many many successful applications in other journal bearing turbos on many other platforms, hey it works. Dont get me wrong, nobody should do a restrictor for preventitive reasons, its a last resort once other things are rulled out. Even recently today I saw a youtube video of a guy that installed a journal bearing Borg Warner turbo single turbo top mount setup, setup was good with a proper drain and started smoking out exhaust. Turbo was perfect. Installed .060" restrictor and problem solved, turbo running perfectly. Search a little online and you will see in SOME cases where proper CCV setup and proper drain doesn't work, last resort is a proper restrictor because the car is supplying too much oil pressure. N54 does about 70-75psi at WOT. Tony has ripped into me in this thread for bringing this up as a point of discussion saying he has done all the testing necessary and that his word is the final word and I am stupid for even mentioning it. And he wants to basically discount everything learned about journal bearing turbo setups over many many years across many platforms when everything else is good and turbo is perfect but still smoking. Buy that if you want, but I say experience with journal bearing turbos across many platforms clearly shows that after CCV and drain are properly addressed, restrictor is the correct next step for those rare cases that need it. Remember when inlets where invented by TFT, Tony ripped that idea too and said it was not required and did not produce all that extra power no way and he had tested everything and he knew all and we needed just to follow what he says....hmmmmm......oh well, some will choose to believe whatever they want to believe. But generally good discussion here, and lets continue to keep it civil without attacking each other personally and each others products (if that can be hoped for).
     
    Last edited: Feb 15, 2018 at 11:37 AM
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