Turbo Bearings

[Sydneykid]

I would add that comparing a 500 degree C exhaust gas temperature diesel engine turbo with over 1000 degree C exhaust gas temperature petrol engine turbo is rather misleading. Which is very naughty from a professional in the field.

What Slide is saying is that Garret totally wasted their time with designing ball bearing turbos because plain bearing turbos are perfect and need no improvement whatsoever. That’s why Nissan paid Garrett many tens of millions of dollars for the design and supply of ball bearing turbos for their later models. They simply wasted their money. Nissan changed from plain bearings on S13’s to ball bearings on S14’s for absolutely no reason whatsoever. There is no logic at all for Nissan to go to ball bearing turbos on the N1 R34GTR, the plain bearing ones on the N1 R32GTR were just fine.

Hang on, let me look in my service book….oh guess what………..

Nissan recommends turbo charger overhauls on R32GTR N1 turbos at 40,000 k’s but on the R34GTR N1 turbo its 100,000 k’s. So Nissan obviously believes that the ball bearing turbos last 2.5 times as long as plain bearing turbos before they need servicing.

But hey, maybe Nissan and Garrett are just simply wrong.

Somehow, I don’t think so Tim.

cheers

[Cubes]

Who really cares this has been done to death..

We all know BB turbo's offer a longer life and better response/spool than journal bearing turbo's; its up to the individual if they wish to replace a turbo at 100,000km's or 40,000km's while putting up with a little less response. All though I don't believe for one second a well built 360degree journal bearing turbo is that bad, hell even stock VLT turbo's see in to the 300's if treated correctly.

Do remember there is much more to a responsive turbo than its bearing system.

Back to hotshut downs... there really is no proof, I've seen one R34 GTT turbo with stuffed bearings caused by a supposive hot shut down and thats a BB turbo, personally I doubt a single or even a few hot shut downs will stuff a turbo, the only way I see possible is if it was starved of oil when spinning 100,000rpm, which may be possible in a hot shut down situation.. who knows.. I sure as hell dont.

[Slide]

I would add that comparing a 500 degree C exhaust gas temperature diesel engine turbo with over 1000 degree C exhaust gas temperature petrol engine turbo is rather misleading. Which is very naughty from a professional in the field.

What Slide is saying is that Garret totally wasted their time with designing ball bearing turbos because plain bearing turbos are perfect and need no improvement whatsoever. That’s why Nissan paid Garrett many tens of millions of dollars for the design and supply of ball bearing turbos for their later models. They simply wasted their money. Nissan changed from plain bearings on S13’s to ball bearings on S14’s for absolutely no reason whatsoever. There is no logic at all for Nissan to go to ball bearing turbos on the N1 R34GTR, the plain bearing ones on the N1 R32GTR were just fine.

Hang on, let me look in my service book….oh guess what………..

Nissan recommends turbo charger overhauls on R32GTR N1 turbos at 40,000 k’s but on the R34GTR N1 turbo its 100,000 k’s. So Nissan obviously believes that the ball bearing turbos last 2.5 times as long as plain bearing turbos before they need servicing.

But hey, maybe Nissan and Garrett are just simply wrong.

Somehow, I don’t think so Tim.

cheers

You have me mistaken Gary as usual.

Im not disagreeing that Ball bearing turbo's are great, reliable and are not as fussy as journal bearing.

This isnt a plug for journal bearing turbo's i sell both and am happy to sell turbo's at twice the cost of journal for ball bearing.

I have seen the differences and the failures and you are obviously drawn to the conclusion that millions of dollars spent on technology means a flawless answer to the future of turbo's and everybody must follow.

This may or may not be the case however i wonder why everybody doesnt go ball bearing ??

Perhaps they dont seem to see the point you are trying to make Gary.

BUT!!!! Ball bearing turbo's fail under warranty, out of warranty, out of the box.

Journal bearings fail also there is no denying it.

Im just defending that it is not as common as you are making it out to be........

In the list of turbo's there i will point out the Toyota breed in particular being journal bearing, MR2's Celica's Surf's Soarers even Supras have all used journal bearing turbo's with great success and minimal failure.

Not to mention most nissan turbo's have also been released in journal, this also applies for Mazda Citreon etc etc etc

Please research a toyota forum for the hundreds of turbo failures that MUST be happening because of the use of journal bearings.

And lets not forget Trust and Turbonetics and IHI and i can repeat myself again if you like with the rest of the manufacturers.

All are use journal bearing in every motor vehicle application.

Where are the failures????????????

Im not saying there arent any but i would not have a full day unless i were repairing/modifying BOTH journal bearing and ball bearing turbo's.

You seem to like turning these sorts of threads into a R32 vs R33 type debate which one is better.

They are both multipurpose with pro's and con's.

Its as simple as that.

Aaron, nice examples there.

But you forget a key thing, are they high shaft/heat applications?

And do all of the trucks, machinery have thier operators just "turn it off" when thier done?

Go to a servo near a solid hill or similar, watch a truck pull in.

See if he turns it off right away

I have actually done line haul runs from Sydney to Melbourne and back up to Brisbane to pass the time on holidays a while ago and you would be obviously blown away by the amount of drivers that just DO turn the key off straight away.

As i have said it doesnt matter what application, Journal bearings are used in all of them still.

When i were using one of my highflows before upgrading engine i did hot shut downs on many occasions and with my recommended oil line modifications i saw no coking of oil the lines were clean and shaft and bearings remained unburnt.

Ill put it down to laziness on my part but there is real life experience for you.

I will be still using Journal bearing and have modified a Biagio GT40 to GT40/92 Garrett specs.

I would also like to point out the fact that 70%++ of truck drivers and car drivers would have no idea about turbo timers or cool down periods and do just shut the car/truck/tractor or what ever it may be off as soon as they come to a stop.

I dont mean to sound like the lone warrior defending Journal bearings, but that is what i am doing.

They are fantastic turbo's at half the cost of ball bearing with minimal operating differences.

They can last as long as ball bearing if serviced correctly and will in some cases even outlast them.

I personally only build, design and re-engineer existing turbo's both journal and ball bearing at a rate of about 15 per day so what would i know?

[discopotato03]

Design or fit together combinations of your own choosing ? there is a difference .

Personally given a choise I would go to an annular contact water cooled ball bearing centre section every time . There are too many advantages with a low friction bearing system that allows the design engineers to use propper high speed compressors and turbines . Bush bearings are a dark age system that was never intended to carry high speed journals , they are cheap to mass produce and easy to strip / assemble . Their low speed wheels are an exercise in greater size/mass (innertia) so not really a step in the prefered direction . Housings designed for low speed wheels are also bulkier and heavier and again not a positive .

If the cost was neutral bush bearing turbos would be a distant memory amongst newer vehices of any kind .

If water cooling works properly there is no need for idling an engine for 3-5 minutes . Unless you've been thrashing it 30 sec to 1 minute is enough with small point contact bearing systems . Remember all the water cooling has to do is waste a bit of heat from the bearing housing and turbine housing which is not exactly a lot of thermal mass .

I personally think the cost of ball bearing turbos is stupid when you consider how simple the cartridge is when pulled down . To use his term urban myth I'm sure Gary is well aware of the difference between manufacturers cost price compared to the retail price . Bearing pack aside the bb turbo is cheaper to manufacture though the material spec of the turbine and its housing can blow it out a little for higher temperature capable materials . Economies of scale can easily push down the cost of the bearing pack .

Sadly ya gets what ya pays for , if you compromise the end result for cost who's fault is that ?

Hands up those who use 87Oct fuel retreads and masonite for brake pads ....

[Slide]

From personal experiance i think the numbers speak for themselves when comparing two turbo's in particular with cost vs outcome

[Roy]

right so why is it that a particular hiflow with plain bearing is more prone to bearing failure vs an oem plain bearing unit ? i dont get it? is there something im missing

Ok im goign to go out on a limb and suggest somehting here. I remember readign an articles years and years ago that stated a pretty obvious prob with hi flows, or more to the point the mixing of compressors and turbines.

BB cartridges do give better repsonse (im a believer that the housings and wheel sizes play a bigger part, i want to see a GCG Hi FLow with BB up against a 360 plain bearing type before im convinced there is a big difference...but) and their main strength is their superior strength and reliability. They are more durable in that they can handle higher axial laods.

When you accelerate a compressor it applies an axial load on the shaft that it is rotating on. Turn on your house fan and watch the thing thrust back as it is switched on. Sam thing. With plain bearing turbos this articles stated that plain bearing turbos are suspect to increasing axial laods from playing with different wheel sizes....notably big compressors on small turbines. This leads to seal and thrust bearing damage.

It seems to make sense to me, ?????

[Roy]

mitsu turbo's are supplied to trust but i dont think trust releases and specs on their turbo's so i pressume the only changes they make are to the housings, evo turbos are different varients of the TD05 and the only larger varients to the td06 is the td07 and then after that trust makes the t67 and etc

http://www.zerotohundred.com/newforums/showthread.php?t=655

...AND???

[discopotato03]

Roy a lot comes into that subject of axial and end thrust loadings with turbo rotating groups . It was suggested to me once that the uneven balance of of pressure in the turbine and compressor housings has a large say . The person said he thought the greater turbine housing pressure tends to make the turbine and shaft thrust toward the compressr end and make the thrust collar try and force itself through the thrust plate . I have also heard it said that 360 deg or full circle thrust plates create a few problems of their own . The extra surface area makes for more oil shear drag so the rotating group acceleration will be a bit lazier . The assembly process is not quite as easy because the thrust collar has to be two piece to bear on each side of the thrust plate . This set up usually requires the use of a dynamic or mechanical face seal in the compressor backplate which adds more unnecessary drag in a blow through EFI application .

We should not believe that its impossible to make a reasonable bush bearing turbo but its very probably impossible to make a wide ranging high performance (read true high speed high boost pressure capable) turbo and expect it to live . No turbocharger application is going to be seamless in its power delivery but a well thought out BB cartridge with the appropriate wheels gets noticably closer . The fact that the rotating assembly has less resistance to revolving in the critical low speed window makes a huge difference .

The real enemy is the suppliers who thought they had us trapped by only supplying BB turbos or cartridges and no spares . One day someone in a newly developing industrialising nation will copy or provide non genuine bits for BB turbos and then the price will drop . Some of you should probably look around in the US for turbo prices and how the difference in currency value affects our prices .

Anyway the home brew is kicking in so nite all ....

[Warpspeed]

Agree with you about the end thrust coming from pressure differentials.

Full boost pressure will be behind the compressor wheel, but the front is only open to roughly atmospheric pressure. So boost is trying to pull the compressor wheel forward. The bigger the wheel, and the higher the boost pressure, the more thrust load is placed on the shaft.

A similar thing happens at the hot end. Turbine inlet pressure gets behind the turbine wheel and tries to pull the wheel out of the back of the turbo.

There can be a fairly high positive pressure behind both wheels, but depending on what the turbo and engine are doing, the forces may be highly unequal.

That can be particularly true for some really wild hybrid turbos that have highly unequal pressure and wheel sizes.

[discopotato03]

Yeah I won't debate in which direction the compressor wants to push under load though I suspect it could be back toward the cartridge given the vane area towards the exducer tips and how the air stream feeds the diffuser section on the backplate and comp cover . Its a given that annular contact ball bearings will have a lot less drag (meaning that they spin up with less exhaust gas velocity - provided they don't have a great galoot of a compressor on the shaft in relation to turbine size) so can afford to be slightly larger with less or no turbine lag penalty .

It would not be impossible to design a bush/plate cartridge that is better than those about ATM from a shaft support and float perspective but it starts to get expensive and bulky again . For example higher wear and temperature resistant materials can be used on the shaft journals/bushes/collar/thrust plate bearing housing , the journal bearings could be further apart to better handle the axial forces and reduce the "orbit affect" that high speed and frequency shaft bearings and journals tend to have . Multiple small diametre thrust bearings could have less drag but where does it begin and end ? Would such a device demand dedicated oil pumps to prime the core and run after the engine is shut down ?

With modern cars and engine bays being such a pain in the ass to work in I would not fit a device with a short life even if it was half the price of a more durable equal . I don't relish having skinned nuckles and fixing broken studs or oil/water/exhaust/air leaks so I don't want a long drawn out development programme in the quest for the ultimate turbo . In the end trying to solve the problems of older technology often takes more effort and money than just buying the right equipment . If drum brakes cross ply tyres and carburettors cost half of what the modern bits do would everyone be still using them ? I wouldn't .

Cheers A .

[Tangles]

If drum brakes cross ply tyres and carburettors cost half of what the modern bits do would everyone be still using them ? I wouldn't .

Cheers A .

Ummmmmmmmmmmmmmmm LOL

On a lighter note; you've obviously never heard a set of fine-tuned racing Flatslide carburettors then? Nothing so sweet in this world then the howl of air being sucked via twin K&N airpods and blasted thru properly setup flatslide carbs into a tight 4cyl, the sound is phenominal - whether that be at idle or on full-tap, whether that be on a performance motorbike (like my Fireblade, 1/5th the price of a turbo setup I might add) or a old-skool car.

anyway - I can assure you its the sound god himself makes first thing in the morning - you gotta love that !

so true.

lol - got a query tho; could you elaborate on your 270degree vs 360degree thrust bearing opinion? I was interested to read that 270's are preferable, why is that?

cheers all ! Brendan

[Slide]

http://www.turbomagazine.com/tech/0405tur_...bo_tech_part_1/

This will clear things up Brendan

[discopotato03]

Well the theory is that greater area for the thrust collar to bear on is the advantage when it comes to wear and tear . If you look at those pics which are probably by Turbonetics you would see that the "270" thrust plate is brass or bronze while the "360" is steel or iron . The original OEM Garrett / Nissan T3 cartridges used the steel 270 type and were reliable when run at std boost . Once Roger Rev Head gets one and cranks 17lbs boost into it they fall to bits real quick . Or plan B if it was "Hi Flowed" by Sick Mate Racing ie TO4B or E compressor and cropped turbine exducer and 17lbs boost the 360 deg plate is of limited advantage .

As I said the full circle thrust plate dictates that you must use the collar (two piece because it has to fit through the plate and contact both sides) oil slinger assembly that suits the mechanical or if you like carbon seal in the compressor end . The best choice for blow through applications is the piston ring type comp end seal because its offers less drag than the alternate type . Last time I asked (10 yrs ago) Garrett didn't make the two piece affair for the piston ring type collar .

The problem with all these T3/T4 bush/plate cartridges is that too many unworkable combinations fit together in a core and bearing system not designed for high performance read constant high speed service . As Gary said the typical Diesel environment has lower EGT's and their usable rev range is not generally very wide . Diesels make good torque at low revs and being work horse engines break neck acceleration is not the main aim , pulling power or torque is . Now the current crop of higher speed commercial and car Diesels aside , truck Diesels use large turbines and adequate compressors because they are designed to run at peak power/boost/revs for long periods of time . The turbo doesn't have to run at stupid revs or unhealthy temperatures because its not necessary and warranty work is expensive for the manufacturers . They put together certain combinations of components , destruction test them and market them . Ford had a really bad experience with the RS500 Sierras in group A mainly because that TA34 turbo was being made to run way beyond its capabilities . Had the GT3037/GT30R (real one) been available it would have been a different story . DJR did make them competitive in the end but mainly because of a technology tie up with the engineering brains of a certain F1 team . It went into more than just its turbo - which had a few sneaky mods to get them there .

Cheers A .

[silver gts-t]

...AND???

im not ready to provide a personal opinon yet

lol

[Roy]

. If drum brakes cross ply tyres and carburettors cost half of what the modern bits do would everyone be still using them ? I wouldn't .

Cheers A .

Why do you think im driving an R32 GTSt instead of an R34 GTT or an R33 GTR, because it costs half as much