Yes, but sometimes when people rebuild then they turn into plain bearing. Dont worry too much though, the difference isn't dramatic.
hey i was just wondering if any one knows for sure if a aus spec t28 of a s15 is BB or not, ive looked at other forums and get so many mixed replies
if canyone could help me out that would be great
thanks ben
Yes, but sometimes when people rebuild then they turn into plain bearing. Dont worry too much though, the difference isn't dramatic.
simple as that . . .
so tehy are, thank you for answering my question. isnt the diffrence that BB you can run more boost and spools quicker, or am i wrong?
Yes you are wrong, the turbos efficiency rate has nothing to do with bb or not, thats got to do more with the size of the turbo, what engine specs your running and how much boost your giving.
Bb spools a bit faster because theres less friction unlike plain bearing (sometimes you can hardly tell, bb turbo companies exagerate and wanabes also dont no jack)
Plain bearing are cheaper to maintain, I have been in cars with both types of turbos, when rallying or racing I can't tell the difference.
IHI mitsubishi have developt twin scroll turbines into VVt EJ20 engines just to improve drivability, however subaru will tell you they are the best turbos ever made. The same with the s15 and jap s14's, just so the car feels that bit more responsive when cruising or traveling around traffic. But theres nothing wrong with that, if you have the extra cash go for it.
Before you go buy the turbo make sure there isn't too much play with the turbine shaft, that is, if the turbine wheel moves a lot to the left or and right, it needs rebuilding.
aus s15 t28 is not ball bearing
just get a rb20 turbo off a r32. not only are they ball bearing, but theyre 200 bucks and t28ish in size
dorio mentioned checking the shaft play left and right, bu also check it forwards and backwards.
find out the part number on the turbo core and that is the most accurate way to distinguish if its bb or not
According to my knowledge s15 t28 are dual ball bearing.
"The Silvia S15 Spec-R is the Japanese version of the U.S.'s 240SX.
This is the stock S15 Silvia Spec R T28 Dual Ball Bearing Turbo."
The ADM s14 t28 turbos were plain bearing.
okay kool thanks for all your help, the onw i looked at is $600 and doesnt have any shaft play. i jsut wanted to make sure it was bb before i bought it.
this turbo is for my sprinter, already has a trbo on it but shit small and the manafold is brokrn so i thought i may as well go something bigger when i got new manafold.
ben
Dorio86 you are wrong
the adm and jdm s15 received different turbos
aus spec = non bb, jap spec = bb
I though they were just de-tuned to pass emissions and run under the ghey 95 octane. Mmm, but I think your right, sorry, my bad.
"VCT SR20 has different inlet plenum position (similar to the CA style), the rocker has a hump on the back and on the front of the motor (head area) there's some bit sticking out. S14 SR20 came with the T28 turbo, but apparently the last batch of S14a jap spec came with T28bb. all jap spec S15 SR20 came with T28bb, apparently the aus spec S15 only came with T28 not ball bearing but bush bearing (dunno how true on this cuz it's still debated on).
and the S13 model series redtop and blacktop all came with T25g. the only difference is the colour of the rocker cover and maybe the factory tuning is different cuz there are 3 different series of computer for the S13 SR20."
"Hmmm... my Aust spec S15 came with a T28bb..."
"All s15 Spec R had t28BB turbos
Dunno about Spec S i think they are the ones with bush bearing turbo (though definately know they have less power and are all AUTO)
All S13s had t25G turbos
though i dunno what the Update model RPS13 180sx had (anyone help here?)
as for S14s they had different ones depending on what model you get.
And last but not least Good old Gti-R Has the best one of all a higher flow version of the T28bb.
Not sure just how correct my info was 90% sure but"
Taken from: