T28 Ball Bearing And Non Ball Bearing Turbo, Lets settle this once and for all. Options

[Alex]

I came accross and interesting article earlier that might solve the BB/nonBB dilemma. Ive heard different stories from people and read many things and still am not sure which models had BB and which didnt.

Basically ALL t28's for ADM s14/15 use the following part no's:

Jap PS13 14411-50F00
AU/NZ S14 (pre-facelift) 14411-75F00
AU/NZ S14 (facelift) 14411-75F00
Jap S14 (pre-facelift) 14411-69F00
Jap S14 (facelift) 14411-82F01
Jap S14 (Autech/270R) 14411-RP801 (Same as S15 early MT turbo)
Jap/ NZ S15 (early*) 14411-91F00 Manual model only
Jap/ NZ S15 (early*) 14411-69F00 Automatic models

Jap/ NZ/ AU S15 late* 14411-75F00 Same as NZ S14 and same for both Auto and manual

Also here is a letter from Nissan, Cust relations:

With reference to your inquiry about turbos, we advise the following:  S14 & S15 use the same turbo, which is a Garret T04B, with "plain bush" type bearing.  Roller bearing turbos are only on Japanese domestic model.  I trust this satisfies your inquiry.

Regards
Val Davis (Mrs.)
Mgr - Customer Relations
Nissan Australia
ph 03 9797 4111
fax 03 9797 4408

Summary:

The auspec s14/s14a/s15 all came with the same turbo, which is a plain bush bearing turbo (derived from the part numbers, calling the Nissan engineers and turbo workshops such as ATP and AVO.) There were a handfull of t28BB that did infact come in the s14a and s15, but they were lucky pics.

Also the turbo workshops i spoke to mentioned that no t28 they have pulled from an ADM s14/s14a/s15 has been BB.

So auspec S14/15 = None BB T28. JDM = of course.

Here is a list of Nissan dealers to backup the part number for t28.

Nissan
Dandenong VIC 3175
ph: (03) 9797 4111 Motor Replacement Parts

260- 260 Frankston Rd Dandenong VIC 3175
ph: (03) 9797 4111 Motor Replacement Parts

544 Elizabeth St Melbourne VIC 3000
ph: (03) 9347 4533 Motor Engineers & Repairers

2- 12 Clyde Rd Berwick VIC 3806
ph: (03) 9796 1777 Motor Engineers & Repairers

429- 443 Grimshaw St Bundoora VIC 3083
ph: (03) 9467 5888 Motor Engineers & Repairers

138 Whitehorse Rd Blackburn VIC 3130
ph: (03) 9894 2244 Motor Engineers & Repairers

350 Springvale Rd Glen Waverley VIC 3150
ph: (03) 9560 4711 Motor Engineers & Repairers

ATP:1198 Dandenong Rd Murrumbeena VIC 3163
ph: (03) 9569 4764  Turbochargers

[inertia]

you can ?

[1BAD180]

additional info for anyone doing the swap:

was at speedworks yesterday while jims car got tuned, afterwards we had a chat with aj about the turbo and other things, the following came up in conversation:

the factory non bb oil lines have no oil restrictor as the non-bb turbo's need more oil than the bb turbos, therefore if you go from a bb turbo to a non-bb turbo you must remove the restrictor in the oil feed (aj thinks from the block but he's not sure) and put a non bb turbo banjo bolt wihtout the restrictor in or your turbo will be starved of oil and die, if you have a non bb turbo and you upgrade to a bb turbo you need to put in the restrictor, too much oil doesnt damage the turbo it does however blow out the oil seals inside the turbo and your brand new hks gt-rs will last all of 2 months before it seazes(spelling?)

if you have a bb turbo from factory and put in another bb turbo you dont need to change anything, if you have a non-bb turbo from factory and put in another non-bb turbo you dont need to change anything

so... that little banjo bolt that comes with the kit, make sure you use it if your going from non-bb to a bb turbo

have fun

This post has been edited by 1BAD180: May 28 2004, 01:26 PM

[1BAD180]

well basicly the rule of thumb was that bb turbo requires less oil feed so use the restrictor banjo bolt, while the non bb requires more oil so more oil, however with a n/a conversion that isnt something you can make an outright statement on, cuz it all depends where you tap your oil line from and what pressure it is under? i assume from wat jilted was saying about his conversion that different points have different flowing oil thingies or something? i really dunno...

look seriously drop by speedworks and ask the boys what you should do, expect the usual "dont do it" line that all the shops say tho

but yea, if you know you have the oil feed in the right place, oil restrictor for bb turbo puhlease

[Alex]

Stolen from sexy-sx.

There is always a discussion in regards to ball-bearing vs. non-ball bearing turbochargers and the performance and reliability aspects of one to another.

Question: Everyone is asking about ball-bearing turbo's and do they spool quicker than non-ball bearing turbo's. Should I pay the extra $425 which is the difference between a non-ball bearing RPS turbo kit and a ball-bearing unit?

ANSWER: All right! This question has been asked many times and I have yet to answer, so here goes. The main factor that determines when a turbo will start to spool hard is the A/R of the exhaust housing. On a side note, the weight of the exhaust wheel is a factor, i.e. a ceramic wheel. Unfortunately ceramic wheels are very, very expensive and are not readily available in the sizes we need.

Everyone needs to remember that a turbo is basically just like a kid's pin wheel that you can hold out a car window and make spin. If you increase the velocity of the car (i.e. the exhaust going into the turbo) the wheel will spin faster. If you put your hand behind the pinwheel, the wheel will slow down because air cannot flow though it. Let's talk about an engine running at 3,000 RPM, full throttle. The engine will produce a constant amount of exhaust gases as long as the RPM is held constant. So the only way to spin our "pinwheel" faster is to increase the velocity of the air. The only way to increase the velocity of the air is to use a smaller A/R ratio. The problem with too small an A/R ratio is that it will choke off air flow at higher RPM. This is why matching the turbocharger's size, CFM, exhaust back pressure vs. intake pressure, and A/R ratios is so important.

The ball bearing option was developed to improve the reliability of high output turbos. When high boost is used, there are great stresses on the centre housing bearings to keep everything in place. The ball bearing option is a great way to handle these added stresses and improve reliability.

As a side effect of using the ball bearing option, drag cars saw immediate improvements in et's. The reason for this is the ball bearing improved the rate of acceleration of the exhaust wheel, thus boost. Remember, the A/R ratio determines when the boost will start, a freeing spinning wheel (less friction with the ball bearing) will make the boost rise at a faster rate.

It's that simple. The A/R ratio determines when, the friction in the bearings affects how fast.

NOTE: If you plan on running your car hard with boost in the 23+ psi range we recommend for longevity purposes the ball-bearing option. Also, if you are a serious drag racer and want to squeeze out those better ET's that are associated with quicker spooling then this is a good idea. If you just want a fast street car that runs most of the time at 20psi or less on normal fuel, then the non-ball bearing option is a good one for you.

[brotherjohn]

Jap S14 (pre-facelift) 14411-69F00
Jap/ NZ S15 (early*) 14411-69F00 Automatic models

so are these models considered JDM and thus have T28BB turbos??

[Nebuchernezzer]

Another thing to add, even if you don't have the part numbers in hand you can still visually inspect the turbo and see if it's BB or non BB.
Remove the oil drain and have a squiz up inside it, a non BB will be pretty much and empty casing with an 8mm or so dia shaft running through it.
A BB turbo will have another casing inside the first, through a 15mm or so dia hole in this second casing you can see two bushes about 15mm in dia butting up against one another. This has been checked on several garrett made cores and has held true (S14BB, S15BB and GT series). Also 6 bolts holding on the exhaust housing is true for these three turbos but it's not as definite as the internal construction of the core.
I say this because my S14 T28BB is not in most lists of part numbers, not that i remembe the number now but just somthing i recall from the time i was trying to ID my turbo.

[primevl07]

hey every1 1st post on hear, iv got a s14 with a t28bb on it, and was just wondering wether it matters wether the restrictor banjo bolt is on the block side or on the turbo side of the oil feed, i put the restrictor bolt on the block side and now my car smokes, wether its the compresson or the turbo getting to much oil im not too sure any help wud b gud cheers,

[breet180]

Hey mate, just a tip. Try posting in the "Tech Help" Section