Can other T25-flange turbos fit? (GT28R...)

[jumpfroggy]

This is really just a question of turbo fitment/compatibility...

Someone local to me has a pair of Skyline R33 (BCNR33) GT series turbos, looks like GT28R's. They're supposed to be dual ball bearing, GT28R compressor housing, A/R of 42. At first said he had a T3 flange, but now after looking thinks he has a T2/T25 flange with the 5 bolt GT outlet.

I've read tons about DSM's, the vfaq, boards, all that. But there's still holes in what I understand, since most of what I've learned I've never actually seen. If this turbo really has the T25 inlet flange and 5 bolt GT discharge (like the flanges on this: http://www.atpturbo.com/Merchant2/m...D&Product_Code=GRT-TBO-004&Category_Code=GRT), then would that technically fit a stock 2g manifold and O2?

I know there's a lot of varibles involved, I'm trying to understand what they all are. Some assumptions I'm making:
-The T3 flange is similar in shape but bigger than the T2 flange.
-If a turbo has a T25 inlet flange and the right 5 bolt exhaust flange, then it'll fit the manifold and O2 correctly.

And I have some questions still:
Does the compressor inlet matter much? Seems like it's easier to get something to mate up, especially since it's before boost.
Will oil line fittings be a problem, or are they generally consistent among T25 flange turbos?

A lot of people have stated that GT28RS and similar turbos (like the GT28R I'm looking at) will not bolt right up. Why is that? What is incompatible? I've read that a lot of Nissan turbos (SR20DET, etc) are T25 flange, and I've always wondered what would keep them from bolting up to our setups.

I'm sorry if these are obvious questions. I'm sure when I've seen enough then things will be more obvious. But right now everything I've learned is through reading on the net, and sometimes there's just things that I still can't find enough info on. Any info and correction is welcome.

 

[forcefed4]

your exhaust manifold has a Mitsubishi turbo flange, not the same as a T2 flange.

 

[forcefed4]

here is the difference in manifold flanges-

Just enlarge the pics, you'll see why it won't fit.

T2 flange
http://www.turbochargers.com/store/product_info.php?cPath=21_26&products_id=35

mitsu flange
http://www.turbochargers.com/store/product_info.php?cPath=21_30&products_id=381

 

[prostreetdsmx1]

forcefed hit it right on the head. The turbine housing on the DSM is a proprietary housing to Mitsu, The GT series is a T2 housing that is a universal configuration that was adapted heavily by Nissan and a few other companies.

The 16G is a better alternative for you bud.

 

[jumpfroggy]

Ahh, I finally get it! It must be so obvious to long-timer mitsu fans, but I've actually never seen a picture of that flange before (weird). I got confused with the T25 turbo in our cars vs. the standard T25 flange.

So yeah, I see how the 16g is the perfect cost-efficient and easy-install turbo (cost, drop in compatibility, power, etc). What's the other popular alternatives for manifolds/flanges? From what I've read, it looks like people are either using the mitsu flange, or they upgrade to the T3 flange and use bigger T3/T4 hybrids. Are there other flanges that are (somewhat) popular for our flanges? Speaking of T3/T4, if I had a manifold with a T3 flange, could I use GT-series turbos that had the optional T3 flange, or would there still be inconsistencies? (I realize they wouldn't necessarily be cost efficient).

I'm just curious, since I'm not even at 16g levels yet. Thanks forcefed and prostreet, I've always heard that it can't be done but never knew why.

(Found this: http://www.jgstools.com/turbo/tif.html, shows measurements of T25 and Mitsu flanges. Very interesting)