My HKS T04R needs rebuilding, needs new bearings.
Do companies sell a rebuild kit for this turbo???

Is it possible to upgrade the core to a BB one?? Might be worth while if the price isn't to bad.

Cheers

 

Yes, its a standard Garrett T4 big shaft, 360 thrust, dynamic seal. Any Garrett retailer sells the kit (Turbonetics, Innovative, Majestic, CHEAPTURBOS.com, PT, etc. etc.even your local diesel repair shop will have the parts).

Garrett now does offer BB CHRA for non GT series older t3/t4 style turbos, but I'm pretty sure you'll have to buy a new BB center AND both wheels and back plate all assembled. SO in essence, all you will be using from your old turbo will be the comp and turbine housings.

As far sending your turbo in and getting a Garrett BB CHRA, I don't think anyone does this quite yet. You can however send it to either Turbonetics for their single ball bearing CHRA or Innovative for their BB CHRA. Any route you go in trying to get it ball bearing wont be cheap. Do a search in here, this was covered before by a thread I started.

~Mike............

 

Cheers mike I'll get searching.

 

heh, I've since edited and added more info to my post after you quoted me.

~Mike........

 

Just read your previous posts, I have asked for some prices. If they are too high I'll just use wet bearings as I am thinking of upgrading to a GT40 or T51R next year so might not be worth it.

I'll post up what i get back.

Thanks again for your help.

 

Got this back from turbo technics in the UK.

Thank you for contacting Turbo Technics.

I personally do not know the answer to your question. The person that will know about the HKS T04R is on holiday. However, what I can say is that we do not supply rebuild kits to anybody other than trade. If you fit a bearing kit, then how will you balance the shaft after reassembly? If you would like to send your turbo in to us, we should be able to fit new bearings and seals and very high speed balance the turbo for £195.

We do not recommend ball bearing turbos. If the bearings fail then the turbo is scrap, also the polar moment of inertia is increased which means that they spool up more slowly. Give me a ring to discuss your turbo.

Best Regards,
Andy.

 

Ball bearing turbos spool slower eh? News to me...

 

Well there int that much in it.

From dyno experiance the diffrence between a Gt35 and a gt35r hitting 1 bar is about 400rpm diffrence. i thought thats not that much for the extra money?

Whilst at the Dyno i spoke to the Guy who owned the shop about it, he seemed to think the Old Bearing was a better design, Mainly becouse he can take it apart and check it for wear between races but it has no metal to metal contact, once the Turbo has Oil presure going through it the shaft it riding on a Film of Oil (bit like Main bearings) so if its got a 360 bearing fitted it will take alot more load, possably last longer and Cheaper to rebuild.

So for your 400rpm you may be paying a price?

 

Dave Buck,

So here you are!

I've no idea if you're aware, but I still haven't received the throttle-body that I paid you for about 10 weeks ago. I hope all is well in the family, but I got pretty upset when you stopped responding to emails/forum-chat and sms messages.

Please get back in contact, you can always return the money if you can't supply the parts anymore.

Thanks,
Alex.

Apologies for the thread hijack.

 

If your going to compare standard bearings to sleeve, use the same turbo (apples to apples, not apples to oranges). The GT35R has a bigger compressor then the standard GT35. So you have a bigger compressor, yet it still spools 400 RPM sooner, COOL.

The film of oil that the shaft rides on is were the drag of the turbo spooling up comes from. The BB turbo's use very very little oil so they have a much less drag on the turbine/compressor wheel. Is it worth the extra price? Well, thats up to the purchaser, but if it means going a step up in compressor size, and yet still spooling faster then smaller comp, then it may be worth it to some. Not only do they spool sooner, but because theres less drag, they are more effcient and require less energy to keep spinning. So you could very well go up a turbine A/R and keep the same spool as a non ball bearing turbo of the same turbine and compressor wheel and make more power at lower boost and have less back pressure.

The Garrett ball bearing CHRA are very very robust.

~Mike...............

 

Ok, i don't know how the US Garrett turbo's are marked but on our Spec sheet the turbo is the same apart from R which the code says Rollerbearing core, apart from that the spec is the same. Thats Allid Signals Spec Book (just happends to be a mile from my house where Garrett make there Turbo's )

I was told by an engineer that metal to metal contact will Always result in quicker wear through higher Friction, there was all sorts of Problems with the development of The RB core, the Bearings used are not just run of the mill bearings the RB cose is Cutting edge state of the art stuff, Becouse the none of the bearing used could handle the Speed of the Shaft turning,Load and Heat.

Why do you think the 360 bearing cores are still being used? and being used in all levels of top flight racing? becouse they are reliable. No Metal to Metal contact so no wear. the only wear in a 360 is from load.

You say the RB is robust??? thats not what i hear, i hear 30-40k on a RB is about what there good for on a performance aplication. belive me from what i hear from the guys who make and recon these units i'm going 360.

I belive the reason the GT range, RB in particular took off so well is the new lightweight Aerofoil Wheels there using, makes them perform better than the heavy and slow T class that they where being compaired to.

 

How did you break the T04r and how long did the turbo last before it went bad?

 

I used to be a Garrett dealer (Garrett, Allied Signal, Honeywell). Specs from my spec sheets are as follows:

Compressor Specs CHRA Turbine Specs
Max HP: Part No.: Wheel Dia.: Wheel Trim: A/R Ratio: Bearing System: Wheel Dia. Wheel Trim A/R Ratio

660: GT-35: 71, 76mm: 52: .50, .60: Standard: 68mm 84: 1.18
680: GT-35R: 82mm: 56: .7: Ball Bearing: 68mm 84: 0.82, 1.06

There are two GT35 wheels, 71 and 76mm. GT35R comes with a 82mmm wheel.

I am as close to being a Mechanical Engineer as one can get without the piece of paper stating I'm such (Did all the schooling, but quit the last year to study on my own) but my credentials and know how were good enough to land me a job in the aerospace field for a very technical company with which one of my offices is at NASA Langley here in Virginia. So, not only do I know what I'm talking about, but also I'm surrounded by many brilliantly smart people every day.

True, metal to metal will yield in quicker wear. Ball bearings have very very little metal-to-metal shear wear. The ***** roll on a sleeve, not slide and wear against it. They require less lubrication, hence less static and dynamic drag from less viscous drag. They are superior in thrust and axial load bearing compared to the standard journal bearing in standard turbos.

YES, there was some major R&D time for Garrett to perfect the ball bearing CHRA. Theres always R&D time for new technology to become reliable enough for the masses. Its nothing trivial, heat and load and more importantly harmonics were the concerns with keeping them reliable.

Times have changed, technology changes. With the newer materials and technology BB turbos are COMMON place amongst performance enthusiast, highest levels of motor sports AND OEM. More and MORE vehicles equipt with turbo chargers are now using BB stock straight from the original equipment manufacture. Prices have come down due to larger volumes of these being produced. Its life, technology that was once state of the art and reserved for high-end motor sports has trickled down to the common daily drivers and large trucks.

Hers a couple of my previous post on CHRA's:

https://www.rx7club.com/showthread.p...highlight=CHRA

https://www.rx7club.com/showthread.p...highlight=CHRA

There still being used because A: There reliable (as you stated) B: proven technology, been around for ages. C: COST........ Although the BB has come down in cost, its still not very cheap YET. Like I stated already, The BB CHRA's take thrust and axial loads that exceed the standard older bearings and have less drag. If you pay attention, you'll find that the majority of top level motors sports that use a turbochrger, run the newest technolgy in wheel design AND BALL BEARINGS.

They are very robust. They were originally designed for large diesel truck application were flow numbers exceed 700 CFM and boost pressures exceeding 40 freakin PSI CONSTANTLY, not just a quick run down the quarter mile or a 2 hour race. And hearsay in here (this forum, amongst other forums) gets you zero credit. 30~40k on a standard bearing turbo is about the limit of life as well in performance applications. Ask around the forum and see how long turbo's last on high out put rotaries. You actually hear from guys reconditioning BB units?? Better find new turbo guys, because Garrett does NOT recondition their BB units at all yet.

I agree 100%, but I'm not going to ignore the fact that when most hear ball bearing turbo, they think latest and greatest and if you want to keep up with the newest technology you must have one. And its not so much a matter of weight, but aerodynamic changes that make the GT series spool quicker and have so much more efficiency. Just going from memory, Garrett studies show a 5% gain in aero efficiency is greater then 15% loss in weight.

There’s not one thing wrong with the older standard bearings. Even the newer GT standard bearings have been improved upon. They are proven and work well and are reliable. But to not know what your talking about and "play down" the newer BB turbo's in a public forum is ill responsible. If you praise or bash a technology, better have some facts to back stuff up and not hearsay.

It’s going to be the buyer’s decision to pay the extra for BB or not. Keep in mind that the standard bearing cores do not have the same wheels in them when compared to the "R" ball bearings cores in most cases.

Grizzly, I hope you don't take offense to my post. I'm just treating this as a technical disscussion and am simply talking with you in my reply trying to cover all you said. I hate missinformation, so when I see it, I try to set things straight. Sometimes it can be construed as arrogant. There is a difference in information (be it correct or not) and opinion and plain hearsay ("well, I heard.........", or "well my friend of a friend had this happen......." etc. etc.).

To sum it up, the GT35 and GT35R are different turbos having different compressors. The "R" after Garretts GT series turbo's does not indicate "roller bearing" only, but is a different turbo all together along with having a BB CHRA. And although I'm sure it was unintentional by Grizzly, he did give us proof, that even with a larger compressor, the BB turbo still spooled 400 RPM SOONER then the standard bearing .

Attached are the flow maps between the 71,76mm standard GT35 and the 82mm of the GT35R. You can clearly see the GT35R has some better lungs.

~Mike..........

 

wow very impressive post