View Full Version : Dual ball bearing turbo
Righto folks, I went home from work yesterday, and fitted my T67DBB, gave it a shakedown, then went out and gave it some abuse :) I'd already gotten a load of performance figures from the T67p a few days ago, and I got the same ones from the T67DBB, and these here graphs are the result. Also attached is the spreadsheet with all my comparisons in, and some notes (which you must read before asking questions as it should cover some of the more obvious ones :p )
The conclusion is, the DBB rocks for making the car more driveable. The data shows some impressive gains below 4000rpm which is where a lot of regular driving takes place. I've only done 40 miles in it :D but it feels better and now I know that isn't the placebo effect.
Not much different above 4000rpm but that's what I expected. I've got the same tests from 4000rpm instead of 2000rpm but they are less conclusive as a) the difference is smaller and b) it's far far harder to match the two tests up without skewing the results. So in order to not confuse the issue, I haven't posted any of that up. Suffice to say that above 4000rpm there is still a difference, but nowhere near as marked as below 4000rpm - we are talking 0.05 to 0.1bar boost ahead, maximum.
I also did a gearchange test and that indicated that in fact the DBB behaves exactly like the P-trim, and doesn't lose less boost during the (0.2s long) gearshift. In a 3rd to 4th gear shift, when I got back on the throttle both turbos spun up pretty much exactly the same.
I hope these results are useful in helping you select what turbo you want. They also show if a single turbo is "for you" or not. You only have to look at 3rd gear ratcheting up 15+mph a second to decide that though
-Ian
EDIT - I uploaded the wrong spreadsheet, the correct one is now attached.
good work there fella, but when i got my turbo from powerhouseracing.com, he strongly recommended that a dbb is not worth it on any turbo below a t74 which is there stage 4 i think, i went for a stage 2+ which is based on a modified t67
he said the bearings will wear much quicker on a dbb unit
just going on what jarret told me, thats all
Yes this is true, but the figures spek for them selfs. At the end of the day its a trade off between replacing your turbo once a year or putting up with a little more lag.
Hmmmm, how can a bearing with LESS friction wear out faster?
Garrett must have some nasty warranty claims if their cartridges all wear out within a year ;)
-Ian
really, all those DBB on OEM cars LOL.
Mine seems fine BTW ;)
because they have plain bearings that run on a film of oil, the dbb has ball bearings, which are lubed with oil, but they touch the races in which they run, which causes wear
Well even I can't get longevity data after only 40 miles ;)
And anyway, he was wrong about the performance difference so...
-Ian
There is more than 1 company doing DBB turbos guys ;)
Porsche must be gutted :p and Garrett near bankrupt ;)
What sort of power at the wheels would you expect the turbo to put out??
I looked at the BB Vs Thrust bearing argument when i went for my turbos but with my 300zx theres simply no choices other than the HKS range (2530s) or the greddy range which i went for as its sooooo proven but it is slower to spool up than my previous BB turbos i had on my skyline but i find larger spooling turbos much easier to drive around town :)
Keep up the good work
Mike
Superb write up Ian :thumbs:
Excellent data Mr C. Thanks.
Hmmm, still think it's a 61 for me though ;)
The difference in that speed map is pretty impressive mate:thumbs:
Tricky-Ricky
12-05-06, 17:48
I found that changing to a BB turbo on my S14 gave me quicker spool up at lower RPM and better pick up, and i know of quite a few people that have run BB turbos at higher boost for a lot longer than your average plain bearing turbo, so i'm really not sure where the short lifespan came from, i have never heard that said before.
only re telling what i was told
Don't worry about it mate, it's nothing personal. Jarrett probably didn't have any DBB turbos on the shelf at the time :innocent: ;)
T61's don't spin up that much faster, figure 0.1bar ahead for the same rpm/time according to a brief glance at some datalogs I have. Of course, a T61DBB would probably be a different matter altogether :devil:
-Ian
I'll have a 61 DBB cut right back on the rollers soon, so ill post up the findings.
The difference in that speed map is pretty impressive mate:thumbs:
Aye. Take 3rd gear for example. Floor it at 2000rpm in 3rd and by the time the P-trim is at 59mph, the DBB is at 68mph, and that's exactly the same car, just on boost faster. That's the difference that suprised me the most, I wasn't expecting such a large difference. That's all about drivability, which is exactly what I wanted out of it.
-Ian
Agreed. Can you not now fine tune the map to take MORE advantage of this?
good results there ian, terry you have email
I'll have a 61 DBB cut right back on the rollers soon, so ill post up the findings.
excellent write up Ian, i would be really interested with your findings Lucifer, doesn't Terry S run a T61 DBB, anything that helps low down grunt is defo to be considered
Hmmmm, how can a bearing with LESS friction wear out faster?
Garrett must have some nasty warranty claims if their cartridges all wear out within a year ;)
-Ian
You guys are comparing apples to oranges as we Yanks like to say. The DBB turbos that are available to the aftermarket are NOT the same technology or level of reliability as OEM dual ball bearing turbochargers. Garrett has several divisions, one for OEM applications which we cannot buy, and Garrett Garage which makes aftermarket applications. In the US, you only have two major aftermarket manufacturers of DBB turbos, Garrett Garage and Innovative Turbo Systems. We use ITS turbo's in our kits, but have tested both names. We all agree over here that the DBB turbos tend to wear out faster and experience heat-related fatigue sooner than standard bearing turbos. This being said, DBB turbos were designed for high boost applications in the beginning (1.8 BAR+) so the thrust bearing would not fail from such severe shaft RPMs. They trickled down into the aftermarket slowly and people (like PHR) began to use them on different non-race applications. We've proven countless times on our chassis dyno that the difference in spool-up on any of our smaller turbos (GT60, 62, and 67) is almost not even noticeable. Maybe 2-300 RPM sooner when doing a back-to-back comparison on the dyno. Your dyno's over in the UK are much different than ours, and the method of reading is quite different. Our chassis dyno's have a minimum of 3000# of rolling mass at each tire, which gives more accurrate readings under load. If your doing the testing by rolling into full-throttle at 2500 RPM you will notice a difference in the DBB spool-up. However, in the real world of street driving, who actually gets a start at 2500 RPM? When you lay into the turbo at 4000 RPM, you wont even notice the difference between the two. Those with DBB turbos from us, have you noticed the whine of the turbo compressor wheel long after you shut the engine off? Thats the shaft still spinning along at 100,000 RPM with no oil for 2 minutes you are hearing. We've noticed a significant increase in heat-related fatigue of the bearings with DBB turbos.
Now, I sell both variations in the PHR kits, DBB and standard bearing. I could easily tell the customer that DBB is better and sell them a $700 USD more expensive kit. However, I tell it as straight forward as I know. I advise each customer these facts and let them make up their own mind on which route is best for them.
Jarrett at PHR
Another thing worth checking is the exact size and shape of the compressor/turbine wheels as well as in/exh A/R ratios.
A slightly lower A/R ratio can make a BB turbo look like it's "spooling" earlier, where in reality the difference has nothing to do with bearing friction.
I remember this being the case a couple of years ago in an engineering forum I frequent.
see !!!!!!!!!!!!!!!!!!!!!
It takes 27 seconds for mine to stop spinning off idle, not two minutes. If you don't do a sympathetic shutdown on any turbo you are asking for trouble. There is oil on the bearings, it just gets hot as it isn't circulating, but the water cooling jacket is there to ferry this heat away to stop coking issues (the water still circulates via convection even though the engine has stopped).
My results were from road testing, i.e. real life, exactly how I'll be using the turbo, not a dyno so I dunno why you are talking about the differences in dynos. The road speed graph shows straight away that there is a big difference in the low down drivability of the car, almost 10mph faster. I know no-one in a race or on the drag strip boots it at 2000rpm, and I've said ALL ALONG (did you read the start of this thread btw?) that there is minimal differences above 4000rpm and a T67 is on song almost instantly at those levels. It's the part throttle low to midrange where it makes big strides, and that's where most people drive that car most of the time. I couldn't accurately reproduce part throttle positions while driving on the street, it's almost impossible to hold the throttle within 10% of a given opening for any period of time, so it had to be 100% throttle for the purposes of the testing.
I'm not overly interested in the lifespan of the cartridge ion this thread, this is a thread about the advantages in spool-up over a 360deg bearing turbo in exactly the same setup. I don't want a slanging match over who is right and who is wrong on that front because I imagine you've got no hard data anyway, otherwise you'd have produced it, and we've had no failures yet :blahblah:
I was hoping that people would find this data, which I've busted my ass to get, genuinely useful. Alas so far it's just degenerated into a trader from the states wading in telling me pretty much it's bullshit, with no data to back up those claims. So where, seeing as you have access to the spreadsheet I've produced, have I gone wrong and mistakenly concluded it is a big improvement, hmmmm? Where's your testing results showing DBBs aren't worth the effort?
Pardon the animosity Jarrett, but I'm sure you can understand how annoying this is to me. I was going to link to the results on Supraforums but now I think it'll be more trouble than it's worth if people are just going to say "blah, who sells blah turbos, says it's bull therefore it is". What further evidence can I show ffs? It's better than just saying "there is no difference" or "it spools up faster" surely...?
-Ian
Totally agree Ian. It pisses me off when people post up stuff saying "we've tried x y and z and done all sorts of experiments etc etc" and then totally fail to produce any evidence, usually for some lame reason about not revealing it to their competitors. When I make a decision about what to do with my car I want data to make that decision myself, not to simply do whatever a tuner tells me based on their "experience" and usually without sufficient scientitic or engineering data or reasoning behind it.
Ian, do it anyway, if you think you've got the data and knowledge to back up your reasoning why not post it up.
Ian, can I ask where you sourced this turbo?
Those results look great to me, and I don't care if it does wear faster. After all, OEM parts are designed to 200k miles + . I have not seen anything in any area of aftermarket parts designed/tested to those levels. For us lot it is just not needed/expected.
Finally, a big THANKS for posting this data, everyone says about how they spool 'quicker' but knowing what constitues as 'quicker' has, until now, been left to the mind.
Syed I think its sourced from Boostlogic via Vortex.
Ian this is a great thread, and its great to see some solid evidence of the advantages of a DBB
Just to make it clear, I find the data posted on this thread very interesting, and it's first-hand as well.
Ian let people judge the performance gains by your hard earned unbias data rather than hearsay, and as for longevity, think mine has proved the point as have various HKS DBB turbos that have been around for years.
Good work Ian, very interesting :more:
Your cam should be here in the next couple of weeks, it will be interesting to see the effect it has once fitted.
I'll give you a shout as soon as it arrives.
Just to make it clear, I find the data posted on this thread very interesting, and it's first-hand as well.
Agreed, real world feedback and data from someone with no interest in profit is always of interest.
Agreed, real world feedback and data from someone with no interest in profit is always of interest.
Agree completely. Nice one Ian!
Agreed, real world feedback and data from someone with no interest in profit is always of interest.
Yep.
Ever since the BB turbos appeared, there has been controversy and some degree of dirt-shoving amongst the interested parties (commercially).
It's nice to have unbiased measurements.:)
Thanks guys, I was in a bad mood until I read all your responses :thumbs: :D
I'll do the same for the 272in 264ex cam setup hopefully :)
-Ian
I'll do the same for the 272in 264ex cam setup hopefully :)
-Ian
It will never work, stuff of nonsense etc etc :eow: :drama: :blah: :blah: ;)
be good to see the results, very interested in this
I'll do the same for the 272in 264ex cam setup hopefully :)
-Ian
Looks like you might beat me to this, I am still waiting for my cams plus need to order some cam gears :)
When you planning on doing this?
I'll plan it when I have all the bits in my hands and know what I'm doing for the next 4 or 5 days in a row :)
Then I'll try 1.6 or 1.7bar and see if I can break SCA's dyno :D
-Ian
Ian, excellent data, I am slowly gather ing info and a wee bit of knowledge
Great info Ian - once again, nice job and well presented info.
Terry - how many miles have you done on your DBB turbo now. Are you up in the 10's of thousands now already?!
Excellent post Ian - great to see some facts regarding DBB turbo's :)
Cheers,
Brian.
Terminator
16-05-06, 18:46
Interesting reading Ian, thanks for putting in the time and effort to share.
Pardon the animosity Jarrett, but I'm sure you can understand how annoying this is to me. I was going to link to the results on Supraforums but now I think it'll be more trouble than it's worth if people are just going to say "blah, who sells blah turbos, says it's bull therefore it is". What further evidence can I show ffs? It's better than just saying "there is no difference" or "it spools up faster" surely...?
-Ian
Ian, I was not trying to start any animosity between any US trader such as myself and ANYONE on this forum. I simply posed a question and was trying to make a point about OEM turbo makers and aftermarket ones. Never ONCE did I accuse you of lying or say that your data is "bullshit". Let me get some things straight here, since it seems a few folks have the wrong idea about my previous post.
I sell BOTH versions of our single turbo kits, DBB AND Standard Bearing. I sell the DBB version for $700 more on average. Some folks have insinuated that I was trying to push what I had in stock or on the shelf at the time. Unlike most run-of-the-mill UK and US tuner shops, we carry on average about $500,000 to $1 Million in inventory at a given time. I currently have DBB and Standard Bearing versions of our Stage 1 and 2+ turbos ON THE SHELF. I'll be happy to spend someone's $700 if they truly want me to. However, over here in the US, we dont drive our single turbo Supra's around the street at 2000 RPM, nor do we floor it at 2500 RPM unless we are racing a tortise.
I NEVER said that DBB turbos make NO difference. I've always said that the difference was almost un-noticeable for (KEY WORD HERE) *most* people. And thats EXACTLY what I tell people who call me to inquire on the DBB turbos. On your very own chart, which I studied with great interest, the most difference in RPM I was able to notice at a given PSI was about 250 RPM. At a given RPM point, the difference in boost was about 1 PSI. But thats in the 2500-3500 RPM range. When we are wanting to be on boost fast, I downshift to 4500 RPM and have boost instantly, without a DBB turbo. I do believe your results are wonderful, and I for one appreciate your doing the back to back testing. It just proves exactly what I've been saying all along, that for MOST people, the difference is almost NIL. You probably do feel the difference, having driven and tested both back to back. But most folks wont get that chance. Now do you see what I mean?
Is the DBB option worth the extra $700 cost? Thats up to the customer to decide, not me. I give them my honest opinion after hearing what they are trying to do, period. I've been installing standard bearing and DBB turbos on Supras only for 10 years now. I've driven both back to back on 100's of occassions. To me, I personally feel the differences dont warrant the extra cost for *MOST* customers. For some, it maybe perfect for them. Everyone is different and allowed to decide for themselves, I just give my opinions when someone asks. But most customers who call me up drive their Supra's around town and will never have a chance to put a DBB to the test at 2.2 BAR on racing fuel or dyno both DBB and Standard Bearing units back to back. If you talk to the engineers at Garrett aftermarket or ITS as I do, you'll understand that the entire reason DBB turbo's were created was to improve longevity at higher boost and thrust levels. Standard bearing turbos dont hold up nearly as well to high thrust loads created by high boost as do DBB units, you are very correct there. This is the reason that DBB versions of our GT74, 76, and 80mm turbos are standard in Stage 4 and 5 kits. These kits were designed for High HP and/or race car applications running high boost often.
To make claims that I have nothing to back up my statements is garbage. When we dyno test these units back to back, we do so on a $150,000 Superflow Eddie Current Dyno, which can *accurately* simulate real-world load conditions for a 3500# car. Doing back to back testing, we can replicate and hold 10% Throttle Position or 100% Throttle Position to get an idea of real-world driving conditions around town. We found similar results to yours in the speed vs time graph, although our results showed even less gains than yours did. However, we were testing identical versions of our PHR GT67 turbo, one with standard bearing one with DBB, otherwise exact turbos with same A/R and same exhaust trim (P trim). One thing I have also found is the increased heat load caused by a DBB turbo. Maybe you dont have to deal with heating issues in the UK, but here, none of our professional road-racers will consider a DBB turbo. Those were tried about 4 years ago when we introduced them in our kits as options. Now everyone runs standard bearing turbos and the water temps constantly stay 20-30 degrees cooler running around the track. No data to back my statement up? Are you joking?
And it seems a few folks missed the entire point of what I said about "comparing apples to oranges". DBB turbos are NOT manufactured by the same companies that make OEM turbos that do last 200,000 miles. Garrett Aftermarket and Innovative Turbo DO NOT supply ANY OEM manufacturer. These are private label DBB turbos folks, not made by Garrett or KKK for OEM car companies. The reliability of these has been questioned repeatedly for years since they were released and I am just continuing that process. Whenever a turbo comes back for repair or failure, 90% of the time its a DBB unit. In race applications this is to be expected, but for a street driven Supra, its a big headache.
Again, I sell both DBB and standard bearing versions of ALL our turbos. Maybe next time I'll keep my mouth shut and take $700 more of your hard earned monies, but thats not like me. Again, I NEVER said your data was "bullshit" anywhere in my post. I simply posed the question "is it worthwhile to pay $700 more for DBB" that was it. Funny how things get mis-interpreted over the forums.
Thanks,
Terminator
28-08-06, 09:44
Given the huge competiton in the single market, it is not suprising to me that traders do not post test data as with out spec the data is useless. Specs and maps will never be posted as the companies would go out of businees when we all bought ripped copies from ebay.
As I see it all companies have a right to protect their R&D info. This is nothing new, hybrid twins area case in point, fabricators of these are very protective of their data for obvious reasons. This has been the case in the UK as long as I can remember.
The issue of this big single is better than that, is purely accademic as each will have their own specs that they are working to. So comparisons will be very simplistic.
I think turbo life span on each side of the pond is a different issue. It seems that everyone has a local drag strip in the US, over here access is some what limited. There are few in the UK and most cars have to travel many miles to get to one. As a result they are crowded with daily shoppers and very few runs are possible so visiits are probably less frequent. I would therefore assume that most UK singles of either type do not get anywhere near the top end abuse that US guys dish out.
As has already been pointed out, metal to metal contact accellerates wear. Non DBB turbos have an advantage there, until the seals no longer hold full oil pressure.
It is good to have on the road data, especially when someone is prepared to make it as objective as is possible on the street.
I just noticed this got resurrected :)
You are welcome to post up your point of view and you have a lot of experience in these areas, I've no problem with that. There are a couple of things I must note though:
"the most difference in RPM I was able to notice at a given PSI was about 250 RPM."
Yup, the DBB never races away much like that, but it's a bit misleading as a performance comparison. The DBB gets on boost faster and the revs outstrip the non-DBB turbo for a bit and then, once both turbos are at the same pressure, the revs climb pretty much the same. However, the roadspeed of the DBB turbo car is higher by this point and still climbing, as shown by the Road Speed vs Time comparison chart. In 3rd gear, the DBB car gets from 30mph to 60mph in the time the non-dbb gets from 30mph to about 53, 54mph. So getting on boost has a noticeable difference.
"At a given RPM point, the difference in boost was about 1 PSI."
Have a look at the 4th gear comparison, and you'll see at 4000rpm the DBB was on 0.8bar (12psi) and the non-DBB was on 0.6bar (9psi) so it's a bit more than just 1psi. The higher up the gears, the bigger the difference becomes.
"But thats in the 2500-3500 RPM range. When we are wanting to be on boost fast, I downshift to 4500 RPM and have boost instantly, without a DBB turbo"
Yep, if I want to get on boost instantly, I change down to get above 4000rpm as well :) But my driving style isn't all or nothing. A lot of the time I just yomp away from roundabouts or junctions between 2500 and 3500rpm, part boost and about half throttle. That's what feels stronger now. I never said it'd give more overall power, or spin up noticeably faster above 4000rpm, but it definitely does improve the area below that. If you never see below 4000rpm, I truly wouldn't recommend a DBB! (maybe a 5 point harness and a speed camera detector though ;) )
With regards to the test data I really meant that you hadn't posted anything up, rather than that you didn't have any. But then if you want to post it up or not is your prerogative. I have no commercial reason not to.
And one last bit:
"Is the DBB option worth the extra $700 cost?" - As far as I'm aware the Boostlogic DBB option is more like $150, which is a small price to pay if you use the midrange a lot.
-Ian
I think we both have good, valid points to make about the DBB turbos. I also think we can debate this over and over again for years!
As to BL, I have no comment. All of the normal, large turbo companies have quite a price discrepancy between standard bearing and ball bearing turbos.
I think you are right :) I like it for my driving style, so I'm happy enough :D
BL DBB cores are Garrett anyway :shrug: Maybe their non-DBB cores are overpriced :D
-Ian
I'd just like to add that anyone with a high stall auto setup will gain a lot off the lights. With my old setup I never really saw any positve boost at around 3500 rpms. With the DBB setup I'm getting well into positive boost while using the brake stall.
With the right grip I hope to prove this by lowering my 60ft times a little more~!
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