understanding turbos

bison

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Surface feed problems are the biggest thrust bearing killers. Blocked oil inlets due to foreign objects, aeration due to cavitation at the sump, starvation due to engine stalls while loaded, starvation due to high g force launches, operation with too viscous oil, inadequate oil temp, etc. You will have a big problem really fast with something operating at a close tolerance like a turbocharger thrust bearing and it will fail almost instantly with an oiling problem. The faster the shaft spins the more oil it ejects. Ball bearing turbos will have a very high thrust capacity due to the design. A radial ball that is rolling along a bearing race can withstand many more times the thrust load with much less oil requirement. However they won't tolerate a no oil or carbonized oil situation very long. Carbonization of engine oil due to heat soak back will murder a ball bearing. It's like having sand in the bearing.


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robzombie

Well-Known Member
What you say is all well and good [true] but isn't always what takes out a low mileage turbo with no oil feed issues.

Until side by side comparisons are documented with and without a BOV under the same conditions it will be speculation as far as I'm concerned especially on turbos that are crapping out in just a few thousand miles.

The torsional loads that are generated under full load and throttle cut off should not be ignored either. A BOV will also allow quicker re-spool if you lift and get back in it because of the slower more controlled deceleration of the wheels.

Has the force generated ever been measured on the shaft or wheels under these circumstances especially when the hot side and cold side are trying to slow down at different rates ???

Closing the throttle blade is like locking the brakes and flat spotting the tires and doing the same with a BOV is like having ABS. The wheels are still slowing down in each instance but one is more controlled than the other.

That is the best way that I can explain it in a non scientific way for the people trying to grasp what is happening in that situation.
 

NY Twin Turbo

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What you say is all well and good [true] but isn't always what takes out a low mileage turbo with no oil feed issues.

Until side by side comparisons are documented with and without a BOV under the same conditions it will be speculation as far as I'm concerned especially on turbos that are crapping out in just a few thousand miles.

The torsional loads that are generated under full load and throttle cut off should not be ignored either. A BOV will also allow quicker re-spool if you lift and get back in it because of the slower more controlled deceleration of the wheels.

Has the force generated ever been measured on the shaft or wheels under these circumstances especially when the hot side and cold side are trying to slow down at different rates ???

Closing the throttle blade is like locking the brakes and flat spotting the tires and doing the same with a BOV is like having ABS. The wheels are still slowing down in each instance but one is more controlled than the other.

That is the best way that I can explain it in a non scientific way for the people trying to grasp what is happening in that situation.
It still sounds like ass!:)
 

Mr.Spool

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Nov 6, 2006
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Until side by side comparisons are documented with and without a BOV under the same conditions it will be speculation as far as I'm concerned especially on turbos that are crapping out in just a few thousand miles.
perhaps its how they are built;)
 

bison

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What you say is all well and good [true] but isn't always what takes out a low mileage turbo with no oil feed issues.

Until side by side comparisons are documented with and without a BOV under the same conditions it will be speculation as far as I'm concerned especially on turbos that are crapping out in just a few thousand miles.

The torsional loads that are generated under full load and throttle cut off should not be ignored either. A BOV will also allow quicker re-spool if you lift and get back in it because of the slower more controlled deceleration of the wheels.

Has the force generated ever been measured on the shaft or wheels under these circumstances especially when the hot side and cold side are trying to slow down at different rates ???

Closing the throttle blade is like locking the brakes and flat spotting the tires and doing the same with a BOV is like having ABS. The wheels are still slowing down in each instance but one is more controlled than the other.

That is the best way that I can explain it in a non scientific way for the people trying to grasp what is happening in that situation.
There are applications where blow off valves should be used but 99% of the time they are not required. Hundreds of millions of production vehicles that are turbocharged without blow off valves and failure is very uncommon.


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robzombie

Well-Known Member
It still sounds like ass!:)

Yes and the horse sneeze that some are so fond of isn't the sound of the turbo pressure going up and down which happens to be the wheels speeding up and slowing down in rapid succession because all that boost now has nowhere to go except backwards when it overcomes the exhaust pressure that was driving it especially when slamming the throttle shut during high boost which I've experienced myself personally.

That has to be good for the shaft and bearings right??? ;)

You run low boost so the condition isn't as aggravated in your case most likely.

If you have the answer please share that info with all the dumb asses like me so I can become better edumacated.(y)
 

robzombie

Well-Known Member
perhaps its how they are built;)
That may be true to some extent, I believe it's more of the conditions of how it's used or abused.

I have a truck with an HX40 hybrid on it that I paid 300 for new! Read chinese junk!!

I have over 100,000 on it and have run it to 30 plus pounds of boost on my truck with no issues. The reason is that it has no throttle valve and doesn't experience the boost backing up into the turbo like my TR does and therefore dosen't try to snap the shaft or put all the pressure on the bearings that a motor with a throttle blade does by trying to stop the blades instantly.

So if a 300 dollar POS knock off turbo can live, why can't the high dollar BB turbos that I've seen live, especially the precision turbo failures I've seen first hand in a few thousand miles of use.

Is it the way it's made or is it the way it's used??
 

robzombie

Well-Known Member
There are applications where blow off valves should be used but 99% of the time they are not required. Hundreds of millions of production vehicles that are turbocharged without blow off valves and failure is very uncommon.


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Let's talk about non stock applications like 99% of the turbo failures in the TB community.

I agree that stock apps will live as they are engineered to go 100,000 miles in an unmodified vehicle . Even the lowly stock turbo in a stock TB will live a long time if you change your oil. Issues only happen when things like you stated earlier happen and that can take out any turbo.

I'm not saying that all TR's or anything should have a BOV, just that it should be considered under certain circumstances in which you may benefit from it's use.

They sure are a lot cheaper than buying or rebuilding a turbo every few thousand miles.
 

Mr.Spool

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So if a 300 dollar POS knock off turbo can live, why can't the high dollar BB turbos that I've seen live
I ran a turbonetics bb billet wheel 64 68 as hard as it could go over 30 psi(y)street duty,track duty, no bov on a turbobuick and it never missed a beat.in my area we have alot of turbo cars,I see tnetics, pte,comp,bw etc.I don't know for sure why the turbos fail but I know which ones have a much higher failure rate:rolleyes:
 

NY Twin Turbo

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Yes and the horse sneeze that some are so fond of isn't the sound of the turbo pressure going up and down which happens to be the wheels speeding up and slowing down in rapid succession because all that boost now has nowhere to go except backwards when it overcomes the exhaust pressure that was driving it especially when slamming the throttle shut during high boost which I've experienced myself personally.

That has to be good for the shaft and bearings right??? ;)

You run low boost so the condition isn't as aggravated in your case most likely.

If you have the answer please share that info with all the dumb asses like me so I can become better edumacated.(y)
BOVs may work for some. But I'm sorry, did I forget to mention............They sound like ass!
 

Rafs-T-Type

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maybe its because I am new to this forum, but the search button and I don't get along well. ill try lookin more

thanks
You can search via google. You type site:turbobuick.com [Whatever you want to search for]. It works for any website you want to limit your search to. Then you can use the google search features too such as only show posts in the last year.
 

NY Twin Turbo

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For people like you with money falling out of your AZZ don't use one, you can afford all the parts your car seems to digest.

If the sound bothers you that much you could put a fart muffler on one! :D
In case you can't tell, I'm mostly joking about all this stuff.;)

I'm also dead broke.:(

But just so you know.......In the past I have had other set-ups. And the one that comes to mind the most was my old PT52. I did everything in the world to blow that turbo up. I used to flutter and pedal the throttle all over town! People used to think it had a vacuum powered MACHINE GUN under the hood! Slammed it to no end!!!!! I could not break it! It was turned in to Cotton's Performance in exchange for a Turbotetics 70. I think the guy who bought it still has it today!

So, I don't know what causes turbo failures.

But I do know BOV's sound like ass!:ROFLMAO:
 
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robzombie

Well-Known Member
In case you can't tell, I'm mostly joking about all this stuff.;)

I'm also dead broke.:(

But just so you know.......In the past I have had other set-ups. And the one that comes to mind the most was my old PT52. I did everything in the world to blow that turbo up. I used to flutter and pedal the throttle all over town! People used to think it had a vacuum powered MACHINE GUN under the hood! Slammed it to no end!!!!! I could not break it! It was turned in to Cotton's Performance in exchange for a Turbotetics 70. I think the guy who bought it still has it today!

So, I don't know what causes turbo failures.

But I do know BOV's sound like ass!:ROFLMAO:

Same here, just a little jesting right back at ya.

I thought we were on the same page. These damn keyboards still can't show emotion DAMN IT!!!!!!!

Nothin but love from the ZOMBIE, LOL.
 

NY Twin Turbo

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Same here, just a little jesting right back at ya.

I thought we were on the same page. These damn keyboards still can't show emotion DAMN IT!!!!!!!

Nothin but love from the ZOMBIE, LOL.
Yes.........

Now, with that being said, let's go back to making fun of the guy who wrote post 16! :wtf::eek::ROFLMAO::ROFLMAO:
 

jbeier

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IMHO, for normal street driving or drag racing they aren't needed. I'm sure they make life a little easier on the turbo itself, but I know for me, I'll always have them on my turbo cars whether they come with them stock or not. I like to autocross, and on and off the throttle all the time you do notice a difference in spool time with and without. The BOV is like a return style fuel system (especially if it's a recirc BOV, which I like better anyway) not only does it not slow turbo shaft speed as much, but it also keeps the momentum of the air in the charge pipes moving at least a little bit, so there's already flow in motion when you crack it back open. Like I said, it seems trivial, but it is certainly noticeable. And bonus, if you plumb the outlet of the BOV to the intake tract after the air filter, but before the turbo, you are recycling that filtered air and keeping noise down and flow up.
 

Lockman

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Ok, I know I've posted tons of pictures in the past but I'll do it again for all the new turbo owners.

TO4E compressor cover

PTE casting with 3" inlet and 2" discharge.



It has a .60 A/R ratio and comes on the following turbos.
TE-32, TE-34, TE-44, TE-60, PT51, 52, 53, 54, PT61, T63E, T64E, PT6776E, PT6776RE, GT6776E, GT6776RE. Those last 4 are the same thing, just journal bearing and dual ball bearing. Does require one of the backing plate brackets to be welded to either a standard spring or heavy duty spring wastegate actuator.





TO4S compressor cover

Garrett casting with 4" inlet and 2.5" discharge. Requires a very specific cnc machined bracket to get the wastegate to bolt up close.




It has a .70 A/R and is available on these turbos.
PT61, TE-60, 60-1, PT6776S, PT6776RS, GT6776S, GT6776RS.



Old PTE H cover.



PTE casting with 4" inlet, 3" discharge. Actual A/R was never published, but was close to .75.





New PTE H compressor cover.

PTE casting with 4" inlet and 3" discharge, it has a .75 A/R ratio and the Precision logo casted into the discharge.



Does require one of the backing plate clamps be welded to the actuator for proper wastegate orientation. Turbos this cover is available on, PT6776H, PT6776RH, GT6776H, GT6776RH (again same turbo just different name from different vendor) PT7076H, PT7080H, PT7080RH, PT7180H, PT7280H, PT7280RH, PT7480H, PT7480RH, PT7680H, PT7680RH.
And on non 3-bolt Buick setups, PT70GTSH, PT71GTSH, PT72GTSH, PT74GTSH, PT76GTSH, PT88. Those 70 series turbos should also be available with the dual ball bearing cartridge as well.




Now here is the old school comp cover from way back in the day.

Garrett casted 3" inlet, 2.5" discharge compressor cover.



This cover was used on the old school TE63-1, TE64-1, TE68-1, TE70-1 and TE72-1. It has a .55 A/R and is very hard to come by today. It also required one of the backing plate clamps to be welded to the wastegate actuator for it to bolt up.

These are the covers that are/were sold by PTE.

Hope this helps.

Patrick
Hello Patrick,
Newbie here. I have 2) of the Old School Garrett Compressor Covers, 1 on My 1984 ( Please see Pic ) & 1 on my shop Floor. Both Have a 'M10' stamp on them ? Are they a Good Turbo to run ?
1975-Jeep-CJ-5.jpg
Are they of a certain Value ? Thanks for any opinion ..............
 

marleyskater420

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Let's talk about non stock applications like 99% of the turbo failures in the TB community.

I agree that stock apps will live as they are engineered to go 100,000 miles in an unmodified vehicle . Even the lowly stock turbo in a stock TB will live a long time if you change your oil. Issues only happen when things like you stated earlier happen and that can take out any turbo.

I'm not saying that all TR's or anything should have a BOV, just that it should be considered under certain circumstances in which you may benefit from it's use.

They sure are a lot cheaper than buying or rebuilding a turbo every few thousand miles.
Where are you having your turbo rebuilt at?

You seem absolutely positive that the bearing failure was not due to contaminated oil/oiling issue, regardless of the fact that Bison (a VERY reputable turbo builder) has stated that 99% (or thereabouts) of bearing failure issues stem from something related to the oiling circuit/contaminated oil.

You seem to be justifying the usage of a BOV with the rationality that your turbo failure had nothing to do with oiling-related issues.

I will wager you the cost of shipping and R&R, that your turbo failed because of oiling issues, and had nothing to do with the stress on the wheel assembly from not having a BOV.

I am willing to make a public bet right now, to show that the PTE turbo did NOT fail because of the force of air hitting the wheel after the throttle body closed, which "could have been prevented" if you had a BOV on it, but rather it failed because of oil contamination/starvation/oiling-related issue.

I can give you the address for WORK Turbo, and I bet you the cost of shipping and the R&R work, that you are absolutely wrong about your theory regarding the bearing failure and how a BOV would have prevented this.

Again, I am doing this to show everone that the PTE turbo has an excellent bearing cartridge, and it is not weak and did not fail because of the force of the air hitting the blades after the throttle body closed.

If Reed inspects the turbo and finds that the failure was due to an oiling-related issue, I pay nothing. If he finds that the failure was due to the force acted upon the wheel assembly from the air hitting the wheel after the throttle blade closed, I will pay for your shipping cost, and the cost for Reed to inspect the turbo.

This way we will be able to determine if your entire basis of logic for a BOV has merit, in which case this would be an excellent "case study / example" for the Buick community as to why a BOV may be needed, or strongly suggested. Hopefully this could show the benefits (if there are any) to a BOV, and potentially prevents other cars from having similar failures.

Or the turbo inspection shows that the cause of failure was exactly what everyone else said it would be, and there is no justification for running a BOV, in which case this may hopefully save people money from buying BOV's when they don't need one.

I think either way, this will be quite interesting, and I hope you take me up on this bet, because I genuinely hope I lose so that we may discover a possible solution to help prevent turbo bearing failures for our Buicks, with the intention of demonstrating a new approach (usage of a BOV) that may help save a lot of our Buick Brothers time and heartache from bearing failures.

And just to be clear, this is ALL in good fun. I have no ill-will towards you, no negative sentiments, nothing derogatory towards you whatsoever. I simply saw this thread, saw this opportunity to hopefully get to the bottom of an issue, and decided to take a more "fun / interesting" approach towards discovering the solution!

Hope to hear back from you with a yes!

-Tyler
 
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