kenzo42

iTrader: (6)

1) Why aren't SR20 journal bearing T28 used more often than the SR20 T25?

It seems that the two spool similarly and a T28 wouldn't run out of steam by 6000 rpm, unlike the T25.

I already purchased a BEGi T25 exhaust manifold, and from what I understand, the SR20 T28 works w/ it as well.

2) Would the Begi-S DP work with a T28, with no modifications?

Thanks Sam for the info you gave me.

Dow.tom

iTrader: (3)

my sr20 is a t28 i believe. (the one i use)

Saml01

iTrader: (9)

T28 is just the larger A/R on the turbine correct?

Dow.tom

iTrader: (3)

i thought so, i have a .80 AR as opposed to the .46AR that comes on some of the SR20

240_to_miata

iTrader: (2)

the flanges for the intake and charge pipe on the T28 are clocked at different angles... but unless you are using the stock sr20 elbows this shouldnt matter. if you are, buy addapter flanges or make your own..thats wat i did on my 240

miatamania

iTrader: (9)

I think the T28s are a bit more rare, and expensive...right?

Dow.tom

iTrader: (3)

i believe so, i think the 28 had a .80 AR like my 2 and the t25 had a .46

miatamania

iTrader: (9)

my t25 had a .80 iirc, they came in two sizes.

240_to_miata

iTrader: (2)

the t25's come in a few different sizes, depending on whether it was on a gtir (sentra)... redtop SR or a few later blacktops

the t28 also came in different sizes depending on s14 or s15... only the s15 is fully ball bearing

And yes..they are more expensive

jobambo

From wiki.
The second generation in the S14 Silvia produced 220 PS (166 kW) through the use of Nissan's VTC variable valve timing and a ball bearing turbocharger. The final S15 Silvia version produced 250 PS (187 kW) @6400 rpm and 275 nm @4800 rpm with an improved Inconel impeller wheel for its turbocharger.

I picked up my T28 BB for $201 shipped off ebay.

chriscar

iTrader: (24)

That's a helluva deal.

There's also FWD T25's and T28's. Bluebirds & Avenier's had the T25 (a small number of them are ball bearing), GTiR's had the T28, all are journal bearing.

C

Braineack

iTrader: (62)

AHHHHHHH.

Tom the turbo you have is a t25.

t28 + t3 = t28

all t25s have a 50mm exducer, all t28s have a 60mm exducer...the rest is exactly the same.

the only difference between them is the compressor wheel, a T28 will have the exact compressor wheel I have, a T3 super 60 wheel. 47mm inducer / 60mm exducer.



the t28s are harder to find.....the end.


some t28s come off GTRs and have an odd turbine outlet which requires a different flange.

only JDM t28s have BBs and most likey have said odd shaped turbine outlet flange.

Saml01

iTrader: (9)

The T25 I have sitting on my desk has a .64 A/R on the turbine.

Dow.tom

iTrader: (3)

scott send me your t3, i'll turn it to a t28 than..

Braineack

iTrader: (62)

I have a spare 50 trim t3 wheel....you still gotta machine the housing

the wheel itself is about 10mm taller, which would also have to get milled off so it could fit on your shaft.



tom, here's your wheel vs. my t3 wheel.

Dow.tom

iTrader: (3)

just let me think, i may do it... i know you were thinking bout doing it while you were taking my turbo apart looking to see if they're compatible.

Braineack

iTrader: (62)

yep. i wanted to see for myself what it would take. it's a common upgrade, technically it's all a t28 is.

even now. a gt2860 is a 47mm inducer and 60mm exducer, the same size wheel as mine. my advantage however is the larger turbine.

Efini~FC3S

iTrader: (4)

Like people have said they aren't used as often because they are rarer and more expensive.

The sr20 t25's are a dime a dozen.

Of the journal bearing t28's the one off of the gti-r seems to be the one to have.

jobambo

here are some more info on my T28 turbo.
First the ebay link
http://cgi.ebay.com/ebaymotors/ws/eB...MEWN:IT&ih=001

Some close ups.




Part number reads
14411-69F00
466541-1

According to http://www.turbobygarrett.com/turbob...R_466541_1.htm
I believe this is a GT2560R Turbo. For the first time, luck might be on my side.
BTW today is my Bday, if this is a gt2560r i could not be any happier.

kenzo42

iTrader: (6)

Most of the SR T25 turbos I see are like Jobambo's, where the compressor inlet has a 2 bolt diamond shape. However, I've also seen some SR T25 that are round like this. What's the difference (other than shape)?