Can I put a SR20 exhaust housing on a DSM t25 turbo?
 

Question...

Can I put a SR20 exhaust housing on a DSM t25 turbo? the .54 size appeals to me, and I have one but the turbo is pretty well and shot, but I know you can pick up DSM turbos for relatively cheap (actually pretty damn cheap) but I don't want to have to even think about redoing all of the manifold and downpipe work.

I know some of you on here will know something...perhaps most so Samnavy but just trying to figure it all out.

I know Sam did, but he had a lot of problems with his Fraken-turbo I think.

looking at it, it seems that 14Bs ect use a clap system to hold the housings on where as the SR has the housings bolted on with a plate. would be interested in the issues and the results.

as long as the turbines are the same size I dont see why not.

I can't decipher what you currently have. What is your current setup? If I read correctly, you've got a DSM T25 on there that is ready to die... and you would like to replace it with a SR20det T25? Am I correct? In that case...

The AR of the turbines must be the same. The turbine on a DSM T25 is .49a/r, and the most common SR20det turbine is .64a/r. They will not match. I don't know of any T25 with a .54a/r turbine.

There are a couple stock applications in .49a/r that use the Standard T2 bolt pattern, which is how most of the Nissan turbo's come. I think the 300ZX single turbo of the late 80's had it, but don't quote me. If you're looking for a .64a/r exhaust housing with the DSM flanges to mate up to your current mani/dp, it doesn't exist.

The only way I can see you getting the benefits of the .80a/r compressor wheel on the common SR20det T25 is to rebuild your current turbo with that compressor. You'll need the compressor housing to go with it.

I think my Frankenturbo problems were due to having too many parts from too many different mileage turbos. I had a 200k mile turbine housing, a 50k mile CHRA, and a 100k mile rotating assembly. They were certainly out of spec enough with eachother that they simply wouldn't seal right on the hot side. I wouldn't think you'd have the problem sticking with the same hot section and simply swapping out the compressor wheel. Replacing a .48a/r (DSM) compressor wheel with a .80a/r wheel would totally screw up your flow and spool. I wonder if somebody has this combo graphed somewhere.

I swapped a pontiac sunbird turbine housing onto my nissan T25, works fine think it killed some of the spool but my downpipe is weird and wouldn't reach up the extra 1/4" to bolt up to the nissan turbine housing.

BTW, my downpipe is a POS, only reason why i couldn't use the Nissan housing.

Thanks for the info, which basically chalks up to it won't work.

To clarify I have a standard T25 manifold and downpipe, I have a sr20 t25 with a .80 a/r compressor that is shot, the turbo shaft is fine but the seals are all gone to hell so there's oil all on the inside.

What I was hoping to do was take the exhaust housing off the sr20 turbo and put it on a Mitsu Turbo so that I could keep the standard t25 exhaust ports (both in and out) and not have to rebuild the SR20 Turbo which would have bad spooling characteristics with the .80 A/R on the compressor side.

However, like I stated earlier apparently this will not work as the Turbine housings have different A/Rs. Actually I would suppose it would work if they had different A/R's as long as the wheel trim was the same, but I doubt it would be.

just rebuild it....

for swapping housings, a/r are not everything...the diameter of the exhaust wheel must be the same... thats why on a gt30 you can pick a/r ...

This kit:
http://www.gpopshop.com/garrettt2kits.html

This thread:
https://www.miataturbo.net/forums/showthread.php?t=5164

Take your time.

Well apparently if I had payed attention I would have realized that you have already done the very thing I was asking. Fancy that. Very nice write up on it all, what's you opinion of the housing mate up? Spool well, a bit late, etc.?

I think though that it'd be easier for me to just sell the one I have to someone who wants to rebuild it and keep looking. If I get a good deal on a nice sized t25 turbine housing though, I'll probably consider this again.