You may be pleasantly surprised. Just use it and see how it goes.Also the SU will be very forgiving due to the variable choke size which will help get the airspeed up no end.
FYI when I first built my turbo setup years ago we used a T2 off a 1.5 Pulsar and it more or less boosted straight off idle and stopped making usable power at 3500!! We ended up going bigger and bigger and ended up with the biggest T2 available at the time off an 1800SSS Bluebird and looking back that was still on the small side ( but still went really well )

Whats the smallest T25 turbo and whats in on factory?

Yea I was going to just try this turbo but then I was concerned that I'm going to get all this custom manifold work done for a turbo that wont come on until 4000 rpm.

One you get manifolds made if I want to go to a smaller turbo that would involve rework of at least the flange yea? Possibly even lengths and location?

whats you exhaust housing A/R size? the front looks like 80 which is quite big but both can be easily changed over if required to another picked up cheap from silvia forums or other SR and CA engined based forums.
Contact Clyons8 for a turbo manifold also look for a cheap stromberg 1.75 or SU.
Nicks old A14 should have kept it and developed it further woudld have gone better than most ca18det :)
http://www.youtube.com/watch?v=3Rxd6-i10_k

Re the exhaust housing flange while I would be the first to put my hand up and say that I'm not up to speed with the current crop of turbos used these days from memory the T2's were all interchangeable on that exhaust flange ( and we did plenty of changes )so I don't see why the T25 should be too much different. Perhaps one of the other guys could confirm this.
Re the inlet manifold, have a look at what Sikyne has done with his build. I would be tempted to head down that path rather than using a stock manifold as you will achieve a much better fuel+ air distribution and they are not too difficult to make. Just a bit more tubing required.
All that I can say is that this is what I used both super charged and turbo'd and it worked really well.
Cheers
Dave

As B110SSS has said, the T25/28 flange covers a lot of turbos. Some smaller than what you have and some heaps larger. So you will be right with using that turbo to start with and go up or down if required. The standard intake manifold is fine for a draw through set up. I`d use E85 fuel tho. Then you will be able to run 15Psi without intercooling if the distributor is locked and set to 20Deg. Run the thing rich too (.76 Lambda if using E85).
Should make about 120-140HP atw. And last aswell.

I`d spend the time making an exhaust manifold rather than use the factory one w J pipe.
I can do one if you get stuck(PM if you do)

My thoughts anyway.

Cheers

great info thanks guys.
I'll take some pics and look for numbers on the turbo tonight.

From just googling S13 T25 turbo I think mine is .8AR front and .64 rear

I wanna build the ute to run on 98, E85 isnt really an option for me :(

.80 and .64 is a tad big but good with low boost and higher compression.

Saab 95 and 9000 are also common for carbon sealed t20 and t25 they are around .48 to .56 are on both ends in/ex. Saab @ 1800rpm achieve almost 70% torque so quite early boost but they have 2ltr to play where otherwise their NA 16v engines are quite torqueless down low unlike modern VTEC/VVT and variable capacity inlet manis.

Simon builds great stuff Id definitely get the whole engine built and tuned by him if he has time and use e-go.com.au for cheap freight to and from him. Otherwise a mani from him would be the goods.

be careful with some of the saab turbos, many of them run lowish boost and have tight exhausts. good for spoolup but end up really hampering things up top above (say) 5000rpm or so. You don't need sky high revs for a boosted engine, mind you, but even by those standards the saab turbos can be tight. Also be careful that there were some oddball saab motors that had the turbo exhaust fed by only 3 of the 6 cylinders (but boost was supplied to all cylinders) so you had sort of 2 3 cylinder motors, one with restricted exhaust from the turbo, the other getting free flowing exhaust but boost in the intake, so a 'little' bit like supercharging, at least in terms of the cam timing for those 3 cylinders. point being they won't work properly (far too tight an exhaust side) if you try and run them on anything else. To be fair I have NFI if those particular engines made it to Australia in any significant numbers if at all.

Ok just looked at rear housing it is indeed .64 exhaust

also took a photo of the id plate:




A friend of mine is pretty turbo savvy. He has played around with a lot of them on 4wds.
He is convinced that this turbo is too way too big and a waste of time. He thinks I'd be better off using something off say a Charade turbo or TX3 laser. He simply said a old 1.4 wont have enough exhaust gas to drive a turbo off a modern 2L. Logical argument...

D your comment re "tad big but good with low boost and higher comp"

can you please elaborate?

basically I'm going to run a standard motor. Which from what I have read means I want to run no more than 10psi Max and hope to get the turbo to start producing decent boost at 2000-2500 RPM and maxing out at standard A14 redline of around 6000RPM (that is standard redline yea?)

I just want to know should I abandon this turbo completely as it will simply never do this? The whole just use it and see how it goes doesnt really work when you have to pay someone to make fully custom exhaust and inlet manifold. I dont wanna spend over 1000 dollars on T25 manifolds just to find out its only producing boost at 4k and above.

Thanks in advance guys...