RB25 turbo is not a T28

[pirate87]

I hate to open up this can of worms, but upon researching/rebuilding my RB25DET turbo, I found that there is nothing T28 about it.

Reading through various sources I've heard T28, T28/T3 hybrid, T3...but no difinitive answer to what the turbo actually is.

Looking through some Austrailian skyline archives I found that it's actually a T3 made by Hitachi.

Can anyone else confirm this?

Really this is just a response to:

from: RB25DET Turbo Specs

depends on what generation

both S1 and S2 will be a t28/t3 hybrid, but the S1 turbos have a ****ty ceramic exhaust wheel that will explode/fall off under higher boost (1 bar-ish) while the S2 wheels run a steel wheel that is safer higher but is still well outside of the efficencey range of the turbo.

Modified by pirate87 at 1:53 PM 11/8/2006

[Chaos the Xile]

it is a T28, its the same turbo used on the S14 and S15 Silvia.

[Joe]

the rb25 turbo is shrouded in a huge veil of conspiracy and mystery.

talking about it only angers the skyline gods and puts all of our lives at risk...choose your words carefully....

[Joe]

but seriously, its a t28 intake side, t3 exhaust. (thats what ive always been told, and thats what the horsepower numbers support)

as for it being the same as the s14 and s15 turbo, i dont think so as the output flanges are totally different. (i doubt the internals are the same)

whatever it is, its too damn small to make any more power than 300whp stretched to its absolute maximum. 265-275 is about the average safe limit.

[pirate87]

I'm going to have to disagree with you there: 1. I bought a T28 rebuild kit, very few, if not any of the parts fit.

2. from: http://www.gcg.com.au/Catalogu...t.htm

"The factory Turbocharger on a Nissan Skyline R32/33 GTS-T is a Ball Bearing, T3 sized unit, with a ceramic turbine wheel."

I just dont see how it can be a T28.

let me call up some pics and a diagram or two....

[Chaos the Xile]

WEll maybe you hit the nail on the head, Kamin said that it's a hybrid there in his explaination, that would explain the rebuild kit not working in your favor. As far as the Silvia turbo's go I have seen stock S15 motors over 300HP with the STOCK turbo, maybe not S14, but the S15 yes.

[pirate87]

ok, here's my personal argument for it being solely a T3:

here's the RB25 exhaust housing, as you can see on one side there are 3 housing bolts...meaning 6 in all.



Here's a diagram for a T28, as you can see here the exhaust housing has only 4 bolts.

[Chaos the Xile]

Well I guess you make a valid point there, the diagrams don't lie. Looks like we're the ones who got lied too about our dear RB25 turbo

[Joe]

ok thats the exhaust half (t3, like i said)

now measure the inlet, and count the fins.

its possible weve all been wrong, cause nobody have ever cared this much about a ****ty turbo haha

[pirate87]

really, I'm not concerned with HP numbers right now, I just want to get this beast running. To do that though, I have to know what I'm working with...hope this clears everything up for the RB community. I think Joe put it best saying

the rb25 turbo is shrouded in a huge veil of conspiracy and mystery.

talking about it only angers the skyline gods and puts all of our lives at risk...choose your words carefully....

[Joe]

really, I'm not concerned with HP numbers right now, I just want to get this beast running. To do that though, I have to know what I'm working with...hope this clears everything up for the RB community. I think Joe put it best saying

good luck with the rebuild!

i havent found a shop that can do it yet! nobody can get parts for it.

if you havent got yours running in 3 weeks let me know, ill sell you my turbo. new one goes on as soon as my series is over

[pirate87]

ok thats the exhaust half (t3, like i said)

now measure the inlet, and count the fins.

its possible weve all been wrong, cause nobody have ever cared this much about a ****ty turbo haha

eeegats! your right, i read your post wrong...let me go check the inlet side.

[Chaos the Xile]

Now that I think about it, lets take this into consideration, what about the t25/28 that HKS makes? May not have the same exhaust housing as a true t28, but the internals are a t28, the exhaust housing has been modified for better flow, maybe thats all this is...

[pirate87]

Here's the compressor housing:



And here's the T3 diagram, notice the position of the housing bolts, a perfect match to the above photo:



As far as I can tell, this sucker is T3 through and through...however the piece between the two housings, where the oil inlets go looks way more like that of a T28 than of a T3. So maybe the internals are T28ish?

[pirate87]

what it seems like is that it's T3 housings and T28 shaft/internals...either way, it renders the T28 rebuild kit I bought mostly useless as every part except for the shaft housing seems to be T3.

I wish I had the money right now to just scrap this piece and upgrade, would make everything sooo much easier. ehhh well, when I finally get the junk apart I'll put together a RB25 Turbo rebuild write-up.

[Chaos the Xile]

There you go, sounds like a plan, hey if you get the money after income taxes I'll sell you my GT35R when I upgrade!

[Joe]

that would be awesome! haha

and again, if you cant figure it out ill be selling my stock 25 turbo soon!

[maroon240]

Keep us posted I wanna follow this.

[pirate87]

Alright guys...

Now I understand why no ones ever investigated this, let alone tried to rebuild this sucker. Basically, it is next to impossible to seperate the exhaust housing from the shaft housing, aside from that the parts inside the shaft housing are different from the T3 and T28. As I mentioned above, I read on one of the australian sites that the turbo is manufactured by Hitachi. This would explain why the "interior" parts are different.

i havent found a shop that can do it yet! nobody can get parts for it.

I am realizing why this is true, haha.

Basically my conclusion is that trying to rebuild this turbo would cost more, and take way more effort than would be practical. So sorry guys, I dont think I'm going to be able to come up with a write-up. Unfortunately a new turbo seems to be my only option at this point. This is also one of the few flaws I've found in Nissan's engineering.

[themadscientist]

Got the one with the plastic compressor wheel?

[pirate87]

no, the wheel is definately metal...it hurt my hand pulling the thing off

The plastic/nylon wheel was from the series 2 turbo correct?

[cdorhout]

Hey Pirate87, now that you're not going to rebuild that turbo, do you want to sell it to me?I could use some parts off of it.

[Darius]

I smell something cooking

[gawdzilla]

i'd consider it a T3... regardless of what it is.. replace that POS already!

[pirate87]

Hey Pirate87, now that you're not going to rebuild that turbo, do you want to sell it to me?I could use some parts off of it.

I'd be glad too, I'll send you an email.

i'd consider it a T3... regardless of what it is.. replace that POS already!

I like the way you think sir!