[KBlake]

Hi Ken,

I think you have accidentally given credit for this terrific accomplishment on a 2.2L to the turbo bearings as opposed to all of the actually reasons. Scott's hard work, investment in mods, and terrific tuning abilities are really worth recognizing.

Bruce

I didn't say the thrust bearings were responsible for the excellent spool Scott has achieved, I simply pointed out that he did it with a thrust bearing turbo, and nobody with a BB turbo can beat his spool.

Ken

 

[Bruce H.]

I didn't say the thrust bearings were responsible for the excellent spool Scott has achieved, I simply pointed out that he did it with a thrust bearing turbo, and nobody with a BB turbo can beat his spool.

Ken

And nobody with the same turbo, or any turbo with those bearings, can either...or even remotely get close for that matter, but why let that get in the way of a good BB bashing

I believe the fastest spool on a 2L (200 ~ 2860rpm) was with a BB turbo with no spooling mods or tuning, but I don't think either example had anything to do with bearings and shouldn't be used in any argument to prove or disprove anyones claim that one bearing spools differently than another. There is no proof, and there likely never will be so long as there are no identical turbos with the only exception being the bearings. Any miniscule difference that bearing type might have on spool is completely dwarfed by all the major factors that do affect it...but you already know that

Bruce

 

[mike brinlee]

do turbonetics, garret,etc not have some type of flow bench set up for turbos that could prove or disprove the spool up argument?...
it seems to me that would be the only real way to do it in a controlled environment..

 

[Turbo_PePe]

Also, BB cores -are- rebuildable. There is a company here in aust that goes to the extent of replacing the cartridge casing with something stronger.. and replacing the balls in the bearings with something more durable still.. etc. More to the point, not many people are willing to rebuild them. But it can be done and its not actually that expensive.

-Tristan

Ball Bearing cartridges are absolutly NOT .... NOT rebuildable.
try to contact turbonetics .. innovative turbo .. preciasion turbo garrett or any one that sells BB turbo's they will all tell you they are NOT rebuildable.

its also easy to see . if you would take off the housings , and remove the some sort of cup behind the turbine wheel you'll notice a pressed in seal. which cant be removed. also the ball bearing fit in some sort of half round space on the shaft. thats where the ball bearings move in. so its pretty easy to see why they cant be rebuild.... just beacause they are pressed with some sort of heavy machine.... its quite obvious if you would take one damaged gt BB a part youre self.

 

[Emartoo]

8) SFLMR2 or Emartoo find the thread a year later and decide it's just the turbo for them, and resurrect it, to see if anyone ever ponied up the cash to do the testing.
The End. :angel:

Ha ha, I too am honored. *Emartoo and SFLMR2 high-five each other*

You should work for TSF, Ken. They could really use your help with their custom TSF46B. We'd find out if even the great Ken could sell a turbo with a single 11 psi dynograph making sub-CT26 HP. After working your magic on some BB TSF46B's, I'm sure the performance benefits would be undisputable.

 

[KBlake]

Ha ha, I too am honored. *Emartoo and SFLMR2 high-five each other*

You should work for TSF, Ken. They could really use your help with their custom TSF46B. We'd find out if even the great Ken could sell a turbo with a single 11 psi dynograph making sub-CT26 HP. After working your magic on some BB TSF46B's, I'm sure the performance benefits would be undisputable.

Glad you liked it.

You should know by now that I don't sell untested products. When I helped found KO Racing, one of the basic tenets of the company was offering dyno tested products to a community that was busily buying up turbo kits from the likes of LB. Kits that didn't exist anywhere but in his imagination, until he funded the "development" from his initial GB, then delivered product 10 months later.

I now work for ATS Racing, who have gone a step beyond KO, and purchased a Dynojet, which allows us to perform exhaustive testing on all of our products before we sell them.

There are two examples of companies that have followed the same business model and enjoyed success in this community. TSF should follow their example if they also wish to be successful here.

As far as my magic sales abilities go, it's not hard to sell good products when you have a stack of dyno plots and customer testimonials, but you have to generate the first, and earn the second.

Ken

 

[3sgtemr2t]

^^^ you guys just bought a dyno?!!!! wow now more tested products sweet!!^^^

 

[ATSAaron]

^^^ you guys just bought a dyno?!!!! wow now more tested products sweet!!^^^

Yep, just got it 25 short months ago. ;-)

Aaron

 

[Guest]

Here's a comparison on my SRT where we swapped the old GT3040 for a .50 Trim T3/T04E....
Both were running 20psi and tuned for 11.8:1... runs where taken with the same settings on my 1100 mustang dyne in 4th with pulls starting at 2500RPM.
You would have thought the GT40 compressor would easily make more power than the smaller .50 trim... nope.

 

[KBlake]

You would have thought the GT40 compressor would easily make more power than the smaller .50 trim... nope.

That simply means that the turbo wasn't a bottleneck in your case. I had a similar situation, where a very similar engine to mine was making quite a bit more power than me with the identical turbo kit, at the same boost level. The largest difference between our setups was the fact that he had an aftermarket intake manifold, where I had an extrude honed stock one. I installed an RMR intake manifold and picked up about 40RWHP at the same boost level.

If you already have the engine's Ve maxed out, installing a larger turbo isn't going to do anything but add more lag to the system, which your dyno clearly illustrates.

Ken

 

[Guest]

That simply means that the turbo wasn't a bottleneck in your case. I had a similar situation, where a very similar engine to mine was making quite a bit more power than me with the identical turbo kit, at the same boost level. The largest difference between our setups was the fact that he had an aftermarket intake manifold, where I had an extrude honed stock one. I installed an RMR intake manifold and picked up about 40RWHP at the same boost level.

If you already have the engine's Ve maxed out, installing a larger turbo isn't going to do anything but add more lag to the system, which your dyno clearly illustrates.

Ken

IMO the turbine section of the GT3040 was the bottle neck because when we switched to the .50trim T3/T04, we had to adjust the boost controller down aways. This generally means we picked up exhaust flow and seeing as nothing else changed nothing is left but the turbo.
So no the compressor wasn't the bottle neck, but the turbine wheel sure was.

Also it should be noted the GT3040 does build boost earlier but as per the dyno (which happens to be a very close to road conditions simulation) you can see which makes power earlier

 

[Guest]

Another note- I have my GT3040 being rebuilt as we speak, Garret and others may not rebuild ball bearing turbos (actually garret doesn't rebuild any turbos, neither does turbonetics)... But a few rebuilders have been rebuilding GT BB turbos for some time, limit engineering and AGPturbo are the ones I know of.

 

[Phothog]

Ball Bearing cartridges are absolutly NOT .... NOT rebuildable.
try to contact turbonetics .. innovative turbo .. preciasion turbo garrett or any one that sells BB turbo's they will all tell you they are NOT rebuildable.

its also easy to see . if you would take off the housings , and remove the some sort of cup behind the turbine wheel you'll notice a pressed in seal. which cant be removed. also the ball bearing fit in some sort of half round space on the shaft. thats where the ball bearings move in. so its pretty easy to see why they cant be rebuild.... just beacause they are pressed with some sort of heavy machine.... its quite obvious if you would take one damaged gt BB a part youre self.

So does this mean i cant go to work tommorow, dismantle a customers GT30 turbo, clean it up, balance the shaft, reassebmle it, fit it to our VSR balancer...

in my own opinion the Garrett GT series turbos are crap...
i have rebuilt several GT turbos and 1 Turbonetics 60-1 ball bearing turbo
i believe the turbonetics set up is much better the the garrett...

 

[kameleon/jdmmr2]

bb cores can be rebuilt and to prve this dynatorque the place i spoke about tears down new garretts to replace the balls in the bearings with their own kind etc. so how arnt they rebuildable? if the bearings can be removed like what ive just said the whole thing can be rebuilt.

 

[dinomic]

Flupstar, as usual, you are bang on the mark! :thumbup

Yes, Garrett BBs ARE rebuildable - the main thing against this though is that Garrett don't supply the individual core components, so for a company to do this cost effectively, they have to have a program where a core's parts can be used across several different builds (eg one turbo has the bearings, another has the shaft, another the compressor wheel, etc).

Before anyone disputes this, I used to work for an authorised Garrett place that rebuilds turbos!

With regards to the spool issue, I think a lot of you guys put too much importance on this spool thing, and don't consider the general RESPONSIVENESS. Also, IMHO, you're wasting your time studying spool up on a dyno, when the conditions are not the same as on the road. After all, unless I'm mistaken, a Dynojet can't have it's load changed (it's an inertia dyno, and works off the mass of the roller). An eddy current load cell dynos allow you to adjust the load, and you can even hold a car at a set RPM under load for mapping purposes. The point is, though, that this spool-up lark tells you nothing!

Responsiveness on the other hand is the key thing, IMHO, as a responsive turbo will be what you notice when you're squirting from bend to bend. But I guess you don't have too many corners in the US!

With regards to comparing the friction in traditional bearing turbos to DBB turbos, can someone answer me one simple question? Why would a DBB have more friction, when it's actually easier to spin by hand than a turbo with a 360deg bearing? When you think about this, also consider that when you come off the throttle after being on boost, the DBBs will continue spinning like crazy whereas the other bearing turbos will slow down quite quickly. To be honest, there are both pros and cons to the behaviour of a DBB turbo doing this, but that's another matter.

With regards to the lubrication of Garrett DBB cores, this is a very important issue. I'd even go as far as saying that getting the oil supply wrong is the MAIN factor in blowing a DBB. They blow if they have too little (excess friction and hence bearings fail) or too much (the excess oil creates too much heat, and the bearings get cooked!). Other than that, they go on for ages!

Someone mentioned Anti-lag. Well, the MAIN reason that ALS is a turbo killer is because of the extreme temperatures going on around the turbo when the ALS is in operation. ALS is basically seriously retarded ignition timing that keeps the turbo spinning but can't create enough power to accelerate the car. The downside is MASSIVE heat. This affects other components (like turbine wheel and housing) before it affects the core, although if the shaft get's too hot, the core has a problem too.

With regards to longevity, the DBB cores are meant to withstand pressures up to 60psi+ (or 4bar relative - a figure thrown around by Garrett themselves). Basically, these are pressures that we probably wouldn't dream of running. They don't suffer thrust anywhere near as bad as a regular bearing turbo, and this is why they can handle so much more boost where a normal turbo would have thrust itself to death.

Anyway, back on topic. Flupstar was also right in that the core is the most expensive part of the turbo, so it's quite a change to fit one of these. You're probably better off getting a new turbo altogether. The added benefit of this is that you'll also possibly be getting one of Garrett's latest aerodynamic designs for compressors/turbines - IF you choose the right bits!

 

[thwam]

What would those bits be, dinomic?

 

[KBlake]

The point is, though, that this spool-up lark tells you nothing!

Responsiveness on the other hand is the key thing, IMHO, as a responsive turbo will be what you notice when you're squirting from bend to bend. But I guess you don't have too many corners in the US!

It tells you whether you will have to downshift when passing (overtaking in UK-speak). It tells you whether you will need to gear down for that long sweeper, or if there will be boost on tap when you hit the gas at 3500RPM.

With regards to comparing the friction in traditional bearing turbos to DBB turbos, can someone answer me one simple question? Why would a DBB have more friction, when it's actually easier to spin by hand than a turbo with a 360deg bearing?

I'm not saying they have more, but I'm saying they can't possibly have LESS, since the 360 degree bearing already has the shaft riding on a film of oil, not the bearing, so there is no metal on metal contact.

Ken

 

[Guest]

With regards to the spool issue, I think a lot of you guys put too much importance on this spool thing, and don't consider the general RESPONSIVENESS. Also, IMHO, you're wasting your time studying spool up on a dyno, when the conditions are not the same as on the road. After all, unless I'm mistaken, a Dynojet can't have it's load changed (it's an inertia dyno, and works off the mass of the roller). An eddy current load cell dynos allow you to adjust the load, and you can even hold a car at a set RPM under load for mapping purposes. The point is, though, that this spool-up lark tells you nothing!

My little graph was created on my Mustang MD-1100 which is an Eddy current dyno. Also it was done in vehicle sim. mode which has been proven to be very close to road loading.

I'll side with the BB turbos interms of lower end responsiveness...
Even the mismatched GT3040 had decent low end boost, 5 psi @ 2K...
if that big compressor had not been in surge, it might have been fun.
I think a DBB .50 trim / .76 trim T-31 would be a lethal combo as that wheel could stand alot fast spool without surging.

 

[dinomic]

It tells you whether you will have to downshift when passing (overtaking in UK-speak). It tells you whether you will need to gear down for that long sweeper, or if there will be boost on tap when you hit the gas at 3500RPM.

Ken, read what 3SGEturbo wrote after you. The responsiveness of a BB core can help here. OK, the bigger the turbo the less it'll help, but you get my point about responsiveness.

I'll give a better example. A couple of friends of mine campaigned a ball-bearing conversion for the Evos. Essentially, one turbo company was doing as I said (ie using different bits of a Garrett BB core for different things), so they could fit the Garrett BBs to the Evo's turbo. Now, on paper, that should NOT have changed a single thing, according to what a lot of people have said on this thread. And, on the dyno, you can't really see a difference in spool (maybe 100-200RPM?), but on the road, the BB'd turbo is WORLDS apart
and the responsiveness is insane, especially for what effectively is just a stock Evo turbo with BBs.

I'm not saying they have more, but I'm saying they can't possibly have LESS, since the 360 degree bearing already has the shaft riding on a film of oil, not the bearing, so there is no metal on metal contact.

Sorry, Ken, I don't quite get what you mean. With a DBB core, the oil is just in the bearings, and there's less oil in there too. So the viscous effect of the oil is a lot less.

As I say, why is a BB turbo much easier to spin by hand, and continues spinning for longer?

 

[dinomic]

What would those bits be, dinomic?

The GT35 and GT40 compressor wheel families are the very latest designs. There *are* still turbos in the Garrett BB range that have adapted old technology (like the T04S family), but the new ones are the ones to go for IMHO.

Don't get confused by the numbering! The GT35 compressor is what's used in the GT2871 and GT3071, and the GT40 compressor is what's used in the GT35R and GT3040.