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Author Topic: t25g compressor with stock t2 turbine and housing?  (Read 5643 times)

Offline pakii-afa

t25g compressor with stock t2 turbine and housing?
« on: 01:15:18 AM / 06-May-15 »
Just like the title says lol
I want to know what would happen if I took my t2 turbine and housing and swapped it onto my t25g. Would I get faster spool? Or would it become a hindrance to air flow in higher rpm.

Note: this is a stock ca18et so I'm not looking for huge power, just the most of what I have.

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Offline IggyEGuana

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Re: t25g compressor with stock t2 turbine and housing?
« Reply #1 on: 09:23:26 AM / 06-May-15 »
both would happen. it would spool faster that a normal t25g but it would choke out in higher rpm. If youre having a slow spool on a t25g then something is wrong with the turbo or your engine like fueling or timing. definitely not worth doing. might not even be possible depending on the center section.

back in 2010 i made a couple hybrid small frame turbos. one was a gtir journal bearing t28 center and turbine with a S14 gt28rs compressor wheel and compressor housing. The s14 one was newer and basically was garrett and nissan together improving the technology for OEM cars. The compressor wheels were same in dimensions but the fin profiles were different. The S14 one could flow more peak air without a noticeable drop in spool up. So small bonus there. The housings are where they really differ. The GTIR t28 comes with a T3 sized housing. I forget the AR. The S14 has T4 size. They were very close or the same in internal diameter but with the air travelling a longer distance to exit the S14 unit it is accelerated more slowly and gets less turbulent. The point being that the larger housing is more efficient at high output without sacrificing too much down low. You lose a little but its still very good. The GTIR turbine is a larger AR, .86 iirc. So the turbo spools up slower than a S14 unit but has a higher maximum potential. On paper it should flow around 340hp worth of air.

That one was just a matter of bolting everything together. The second one was more in depth. I made a t25g/gt28rs hybrid. It was just a t25g center and turbine with a gt28rs compressor wheel and housing. The issue is that the gt28rs compressor wheel is a larger diameter than the t25g wheel. The center section has a recess that accepts the compressor wheel so if the wheel is too big it wont fit. But I had access to a machinist's lathe at the time and had the recess in the center section enlarged to accept the gt28rs compressor wheel. after that it just need to be built. I sold that turbo to a friend and installed it on his s14. it ran great and he said it was faster but i never got to drive it. He sold it a little later. I have no clue where it is now but that turbo has my initials on it.

Waylon Deno - Silhouette Autosports (check it out on facebook)
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Offline pakii-afa

Re: t25g compressor with stock t2 turbine and housing?
« Reply #2 on: 08:38:07 PM / 06-May-15 »
No I'm not saying that, I have a stock blown t2 on the car and a good t25g from an sr sitting in my room, I was just simply wondering what the best output could be achieved for a low reving motor like the ca18et. I rarely take it past 5k ever even when driving hard. So in theory a t25g with a t2 turbine and housing (if possible) should spool almost as quick as the stock turbo and drop off around the same rpm? I don't really plan on changing injectors or fuel pump, just a ca20e intake swap, ca18 iinjectors, one step colder plugs (heat range 7) and fmic. Should I leave it alone and just slap it on or pursue my curiosity?

Offline IggyEGuana

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Re: t25g compressor with stock t2 turbine and housing?
« Reply #3 on: 08:49:44 PM / 06-May-15 »
definitely slap it on. The T25g is great on it as is. 10-12psi is all you wanna run with stock ca18et injectors and maf. If you wanna be on the safe side 8psi will still be great. You'll need a turbo outlet made for a sr20 or ca18det and the downpipe to match. that will bolt to your stock cat or cat delete pipe. Theres quite a few threads on here about putting a t25g on a ca18et

Waylon Deno - Silhouette Autosports (check it out on facebook)
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Quote from: Arro
you sir are emblazoned with win.

Offline pakii-afa

Re: t25g compressor with stock t2 turbine and housing?
« Reply #4 on: 09:44:26 PM / 06-May-15 »
When I bought it it came with smic, all stock piping, and elbow, so I only need the down pipe right?

Offline IggyEGuana

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Re: t25g compressor with stock t2 turbine and housing?
« Reply #5 on: 05:46:08 PM / 07-May-15 »
the compressor outlet on the t25 is a little different than the t2. to make it match up to the t2 more you can get one of these


the oil drain is also a little different. if your t25g doesnt already have the drain flange bolted on then get one of these and a new hose


if you have the stock drain for it then you can cut it shorter to make it not point in the wrong direction and then put a new hose on.

Waylon Deno - Silhouette Autosports (check it out on facebook)
Drift Build Thread
Quote from: Arro
you sir are emblazoned with win.

Offline pakii-afa

Re: t25g compressor with stock t2 turbine and housing?
« Reply #6 on: 06:29:49 PM / 07-May-15 »
i was talking about the exhaust side when i said elbow, but i have basically a full stock sr t25g setup, stock intercooler piping, turbo outlet and inlet, smic. exhaust elbow, so i just need to buy the downpipe now. im going to bolt the ca20e intake manifold on first, then turbo, oi/coolant lines then piping then exhaust. i think it should be a pretty straight forward installation.

but that is good info to know thanks