The 2H/12H-T/1HZ/1HD-T/1HD-FT Gturbo Alternative Tech Thread (11 Viewers)

[diby 2000]

There now seem to be several turbo builders offering similar power gains as GTurbo- but for me the question is which one will last the longest?

I asked this question tonight.
After some discussion, I'm convinced that a ceramic ball bearing turbo will outlast a brass journal bearing after thousands of kilometers.
There is a very good chance of making this a complete bolt in kit. This will include a braided oil line, silicone return and hard water lines.
I will confirm more in a couple of days.

Get your engines oil pressure numbers at hot idle and operating rpm and double check its not going to short the turbo oil with his restrictor as our older motors tend to run lower pressure than many other vehicles. Depending on your numbers he might modify the restrictor to ensure adequate flow through the core.

Luke tells me 10psi of hot idle oil pressure is more than enough to keep the turbo happy. Not too much to worry about there I hope. LOL

 

[Wildnlost]

I asked this question tonight.
After some discussion, I'm convinced that a ceramic ball bearing turbo will outlast a brass journal bearing after thousands of kilometers.
There is a very good chance of making this a complete bolt in kit. This will include a braided oil line, silicone return and hard water lines.
I will confirm more in a couple of days.


Luke tells me 10psi of hot idle oil pressure is more than enough to keep the turbo happy. Not too much to worry about there I hope. LOL

I thought I read on mud that there was an issue with ball bearing turbos on diesels because of the soot in the oil wearing out the bearings. More frequent oil changes may be required to reduce this if indeed it is an issue.

 

[Dougal]

I asked this question tonight.
After some discussion, I'm convinced that a ceramic ball bearing turbo will outlast a brass journal bearing after thousands of kilometers.

Yeah no.

Journal bearing turbos don't have anything touching when they're running. It's a dynamic film of oil doing the work and films of oil can handle soot and stuff passing through without issues. A journal bearing turbo will last the life of the engine if the oil and air supply stay good.

Ball bearings touch all the time with rolling and sliding contact. They actually wear out. They also cannot handle any debris as it can get caught between the balls and races. Which is a bad thing at 100k rpm.

Ball bearing turbos just don't last hundreds of thousands of km.

 

[diby 2000]

I thought I read on mud that there was an issue with ball bearing turbos on diesels because of the soot in the oil wearing out the bearings. More frequent oil changes may be required to reduce this if indeed it is an issue.

I asked the same questions. I'm told the issue with bearings and diesel is not in fact the oil or the oil quality but the bearing construction itself. Previously ball bearing turbos had been steel races and steel balls held apart by plastic cages. The issue seems to be multi pronged but comes down to the plastic cages failing due the the sustained loads a diesel places on them with hot exhaust and trust loadings. The solution to this has been to use steel cage construction. Another issue identified was also temperature related with the steel balls expanding and contracting with temperature. Ceramic is much more stable at temperature and is also a harder material that can handle thrust loads better. Ceramic balls overcomes these issues while at the same time providing a smoother bearing surface which reduces wear and also friction coefficient.
You will find major turbo manufactures now using this bearing construction for the above reasons. Even Garrett have recently replaced their steel ball plastic caged bearings and have gone to ceramic ball with steel cages.
Another note I was told was that the Garrett ball bearing turbos were not rebuild-able purely because Garret would not sell the bearing itself separately.
Note 2 -The ceramic balls used in the bearings in Lukes turbos are the only part not made, manufactured or machined in Australia. The balls are imported from Germany, Purely because they are the best ceramic balls he has found.

Yeah no.

Journal bearing turbos don't have anything touching when they're running. It's a dynamic film of oil doing the work and films of oil can handle soot and stuff passing through without issues. A journal bearing turbo will last the life of the engine if the oil and air supply stay good.

Ball bearings touch all the time with rolling and sliding contact. They actually wear out. They also cannot handle any debris as it can get caught between the balls and races. Which is a bad thing at 100k rpm.

Ball bearing turbos just don't last hundreds of thousands of km.

I beg to differ.
Now I'm no expert, I'm gathering info and putting the pieces together myself.
In a perfect world you are correct. The parts would never touch. As it is though, we know the journal bearing turbos on our cruisers wear out before the life of the engine. If the turbo dies so does the engine, but the engine will mostly still go on if the turbo is replaced before it dies.
So if our turbos are wearing out, that means something is changing. That means there are parts touching inside these things. Might not be for long and it might not be huge forces, but they are wearing. Remember this is at factory boost levels where the thrust loads are less than what some want out of these bush turbos. Even Graeme has said that these require a 360deg thrust bush to have any chance of surviving higher thrust loading. The part that is often ignored is the material used in this thrust bearing. The stock thrust bush is made of bronze. The 360deg thrust bushes are brass I'm told. Brass is a lower friction but softer metal that will wear faster than the original bronze, even at stock boost thrust loads.
Take away for me is unless the bushed turbo is rebuilt to stock, its probably not going to last as long as it did up to this point. How long is a ceramic ball bearing turbo going to last? I don't know but I would think somewhere similar at least, but as I said I believe it can outlast the bushed turbo.

 

[Dougal]

I beg to differ.
Now I'm no expert, I'm gathering info and putting the pieces together myself.
In a perfect world you are correct. The parts would never touch. As it is though, we know the journal bearing turbos on our cruisers wear out before the life of the engine. If the turbo dies so does the engine, but the engine will mostly still go on if the turbo is replaced before it dies.
So if our turbos are wearing out, that means something is changing. That means there are parts touching inside these things. Might not be for long and it might not be huge forces, but they are wearing. Remember this is at factory boost levels where the thrust loads are less than what some want out of these bush turbos. Even Graeme has said that these require a 360deg thrust bush to have any chance of surviving higher thrust loading. The part that is often ignored is the material used in this thrust bearing. The stock thrust bush is made of bronze. The 360deg thrust bushes are brass I'm told. Brass is a lower friction but softer metal that will wear faster than the original bronze, even at stock boost thrust loads.
Take away for me is unless the bushed turbo is rebuilt to stock, its probably not going to last as long as it did up to this point. How long is a ceramic ball bearing turbo going to last? I don't know but I would think somewhere similar at least, but as I said I believe it can outlast the bushed turbo.

Landcruiser 1H big end bearings wear out because toyota cocked up the oiling. That's it. It doesn't happen on other engines and they'd fixed it by the 24V versions. Crank bearings on good engines only wear out on start-up when they're dry. On engines which run constantly (i.e. taxis) the engines do ludicrous miles without any bearing issues.

Go dig through these boards for people rebuilding turbos due to oil in the intake. It's never the turbo. A dead turbo doesn't kill the engine either. I've had several expire on me with no issues.

Ceramic ball turbos have been in the petrol aftermarket for a long time now. They are not outlasting journal bearing turbos at lower petrol boost levels. Not even close to matching the life of journal bearing turbos.

The only reason to use a ball bearing turbo is better low end spool. They have less friction due to not using a thrust bushing and this means less shaft torque lost. Radial ball bearings can take some thrust load, but they don't like thrust to be more than about 1/3 of their radial capacity. The more the bearing has been designed for low friction the less thrust load it can take (beause the races are shallower). So higher thrust loads from higher boost and bearings designed for low friction will not be a good mix.

So go ahead and fit a BB turbo. But do it when fully informed that your more expensive turbo is also more fragile and will have a shorter life.

 

[diby 2000]

Thanks for the info @Dougal
More info the better.

If I'm honest I don't really see your point regarding the big end bearings. Are they brass also?

So are you saying people regularly rebuild turbos when not necessary? Do they then find the real issue and then fix that?
Bits of an exploding compressor wheel entering the combustion chamber will do damage to the engine. Granted this is not always the way a turbo fails but it is common on out turbos once the boost is wound up a bit.
Do you have any comments about the wear and shaft play the stock turbos develop over time?

I do realize the advantage of the bearing over the bush with regard to spool. Maybe others did not, but this is the reason I'm liking the idea.
I have been told these MMP turbos do hold thrust loads of >45psi. I can't comment on the actual shaft torque losses through them.

I know this isn't exactly a cheap turbo but as this is the Gturbo alternative thread, it is comparable in price. Probably cheaper for all those on the other side of the world. I don't think Luke mentioned a stockist in NZ.

How long does a BB turbo generally last?

 

[gerg]

I dunno how long they last but I do know they are more susicptable to debris that journal bearings. Coking the housing (produces carbon ) and lots of soot are a bad combo for BB turbos. Be diligent with shut down temps idling to 350f or less and change your oil regularly and what more can you do. Turbos are a bit of a mystery as their life is very user dependent. I do know that much of the bennifit of a BB a turbo cannot fully be realized on a fairly slow revving diesel. Our engines just don't go through the rev range fast enough to feel the response a BB turbo can deliver. It is also worth noting that once the journal bearing catches up rpm wise a second later they perform with almost the exact same characteristics as a BB turbo. Sort of takes away from the BB coolness a lot. It does have a crazy nice turbine and compressor. Now that is worth something. Still though myself I'd get a proven journal turbo and get better performance by fitting an intercooler.

 

[diby 2000]

Thanks @gerg

I know not all do but I run a turbo timer for shutdown. Even then my pre EGT is almost always sub 200C before I turn even the key off.
If soot/carbon buildup is an issue for me/my engine would I see it in the oil filter when cut it open? I don't do this religiously but do it every couple of changes. Oil is always black but I don't see too much as in physical particles stuck in the filter material.
I agree from the research I have done that once up to speed the difference in response and turbo shaft torque losses between the two baring types are so similar its not worth mentioning. But getting the compressor wheel up to speed is where the ball bearing shines. The way I see it, getting the turbo to spool earlier, requiring less drive energy can only be advantageous. I can see what your saying regarding the petrol vs diesel rev range and rate of change but I don't understand how we would not see or feel the advantage of the bearing for spool. Granted at 100km/h we will already be at a rpm where boost is already available but getting there should be completely different. Correct me if I'm wrong (and I'm not trying to poke you here) but would this not be a similar argument to how a twin scroll will have little to no benefit on a diesel? The argument over whether a equal length runners vs a log style split pulse manifold is another example.
I have been told by some turbo builders that both ball bearings and twin scroll (together or separate) will give an advantage over bush and single scroll but the benefit will be so small that its not worth the effort.
I have been looking into exactly how much effort this would take recently, then came across these turbos.

 

[Mcreight911]

You'll have to do oil analysis to get an accurate indication of soot particulates in the oil. A combination of high loads, prolonged hi boost on diesel as apposed to petrols and dirty oil contribute to less life with ball bearing turbos on diesels .

This has been discussed, tested and proved in labs, performance shops and backyard workshops many times .
A lot of Ball bearing turbos are incorrectly sized for diesel application and don't see the high loads or constant high shaft speed that a correctly sized turbo would so they don't have the same reliability issues .

There's nothing wrong with ball bearing turbos but under the the "same" conditions a bush turbo will out last a ball bearing turbo . So if your requirement was long term reliability for a moderate to high boost application on a diesel then I'd suggest bush over ball bearing .

More emphasis should be placed in correctly sizing the turbo rather than the chra bearing type as the spool difference is so small and cannot compensate for incorrectly size turbines and compressors

 

[diby 2000]

Ok thanks. More good info.

@slosh it seems I may be mistaken. Consensus is a bush bearing turbo is the way you want to go for longevity.

So @Mcreight911 are you saying that some BB turbos (those that don't suffer reliability issues) are generally oversized (compressor wheel) for our diesel application?
Can I confirm that means the shaft is not spinning at enough rpm to bring the compressor wheel into its best efficiency range?

 

[Mcreight911]

Over sized compressors are rarely the problem. Usually the turbine housing size is too large and the turbine wheel design not ideal for the flow or heat energy a diesel produces .

I cannot speak for all bb turbos but some are marketed as "never had a reliability issue." The Few I've experienced simply do not respond close to what I would concider good or fast. Therefore if its operating rpm range and average shaft speed is much less than that of a correctly sized turbo then it never works hard enough to have a problem . That's why I say "under the same condition" bush will be more reliable .

I cannot speak for mmf turbo I've not seen or experience one. Form the sizing info mentioned I'd say they are far closer to ideal than most.

When you are told a particular bb turbo spools faster than a bush turbo clarify what they mean by spools faster . Are they referring to boost threshold (the rpm at which the turbo starts making positive pressure) or how long it it takes to go from starting to make boost to when it makes max boost .

 

[diby 2000]

Cool. Thanks for the clarification.
I have a dyno of one of these MMP turbos. I'm waiting for a little bit more info before I post, but I think it looks good.

 

[gerg]

I think the difference is were not selling anything. Not that the fella selling it is trash, but bias is a powerful thing. It changes how you see data. Until you do a back to back comparison it's actually really tuff to say how big of a difference it would have vs a similar size journal turbo. Soot aggrigates to form larger particles. Diesel oil has additives to emulsify soot and try and keep it smaller. Oil filters catch catistrophic sized particles from destroying engine bearings....very large journal bearings that is, not small ball bearings. 40 um is a common filter size, but good filters can get down to 18 if you look for them. 40 um is actually quite a large chunk of debris for a ball bearing. Gas engines don't make soot really so it's pretty much a non issue.

So how much of a response/ difference again is conjecture. I did happen to make a twin scroll manifold actually. Funny you mention that, and have done some comparing vs a single scroll similar sized turbo and there is a very large difference. Is it twice as good? How do you quantify a performance increase? Tuff, but it was worth it for me. I've posted info for folks to see for themselves. Is a BB going to do the same for you? I dunno, but I have been the guiney pig a few times on inventions and it didn't work out. Swapping turbos for me has become like a monthly affair. I'm not fixated on a particular one, But for the average guy it's like you want to be married to the thing. Like yourself, you want it to outlast your truck. Choose wisely and go for for something that has a signifigant track record. Not just performance, but look for tens of thousands of kms.

 

[gerg]

Yeah boost threshold vs response time are huge to a diesel. If your racing the quarter mile, or even light to light then response might be a factor, but a BB journal looses its advantage the higher gear you run.

 

[diby 2000]

I have just re-read the last few pages and would like to clarify a few things.
My goals are to have a turbo that will spool earlier than my stock CT26 and be capable of delivering up to 35psi of boost if the rest of my cruiser will handle it. My cruiser is an auto it will let go of the torque lockup and drop gears if I accelerate so I want it to not drop boost until at least 3500rpm. If my intercooler, airbox or anything gets in the way I may just live with what works, or I may change more stuff. I don't know at this point. My pump and injectors have at least 130000kms on them, who knows when they were done before I bought the truck, so they are potentially the next major expense. I may upgrade them in the process.

So knowing that I would like to run higher boost than most and knowing this is asking a lot of any turbo can you please have a look at the dyno provided and tell me your thoughts?

I'm also hearing that the soot in the oil CAN be an issue so I may not end up going this way. I will have to decide.

 

[Wildnlost]

I have just re-read the last few pages and would like to clarify a few things.
My goals are to have a turbo that will spool earlier than my stock CT26 and be capable of delivering up to 35psi of boost if the rest of my cruiser will handle it. My cruiser is an auto it will let go of the torque lockup and drop gears if I accelerate so I want it to not drop boost until at least 3500rpm. If my intercooler, airbox or anything gets in the way I may just live with what works, or I may change more stuff. I don't know at this point. My pump and injectors have at least 130000kms on them, who knows when they were done before I bought the truck, so they are potentially the next major expense. I may upgrade them in the process.

So knowing that I would like to run higher boost than most and knowing this is asking a lot of any turbo can you please have a look at the dyno provided and tell me your thoughts?

I'm also hearing that the soot in the oil CAN be an issue so I may not end up going this way. I will have to decide.

That is a very nice power curve. I would be happy with. I wonder where the boost is measured at.... the manifold or pre intercooler?

I am currently plumbed into the intake manifold near one intake port for boost gauge and wastegate actuator . I do get a lot of vibration on the boost gauge needle from being so close to the Intake port. (even with a restrictor.) I wonder if the waste-gate actuator can bounce on this pressure fluctuation too?( no restrictor)

 

[gerg]

Your needle flutter is due reverse flow out of your cylinder. Hard to avoid being so close.

 

[Wildnlost]

Your needle flutter is due respect flow out of your cylinder. Hard to avoid being so close.

As a newb to this where is a good spot? I wouldlike to get a boost reading that coincides with other peoples readings. Apples to apples.

 

[gerg]

I meant to say reverse flow. It's also called reversion. It's when your piston is on an upward stroke and your intake valve is still open to allow the intake flow to force its way in as it's still got signifigant momentum and can pack a bit more air in the cylinder. Certin gauges are more susceptible than others. I'd tap in anger place and trial and error it. Since you don't have a throttle plate it wount make a crazy difference where in the intake piping it is. That's a guess mind you. If it drops your reading a pound or so just factor that in when mapping. Honestly what your gauge reads is all intake piping pressure and not in cylinder pressure so this is all semantics sort of.

 

[IanB]

As a newb to this where is a good spot? I wouldlike to get a boost reading that coincides with other peoples readings. Apples to apples.

The factory sensors for the dash lights are just behind the airbox, that's where I took my signal from.