Tiny Little Tractor (Turbo Build Parts List)
 

Just to be clear this is still a build for a Miata, the one in my signature.
My goals are to increase low end torque and really make the car feel powerful. I would love to have around 200 hp at reasonable boost levels.
Got my doors blown off the other day by an old rusty CRX, haha. It was embarrassing, lets not let that happen again.

I have been putting together a parts list for some time now and I would like feedback on my plans.
First and foremost, I would like to know if the turbo I have is a good candidate for my goals. Do you think it was have a fast spool?

It is a T25 from guess what? A tractor!
It needs rebuilt, lots of play. It needs clocked, I will mount it "upside down". As with most diesel equipment applications it has no waste gate. I plan on running an external one. Oil Cooled only.

Here are some specs:
Model T2505
Part # 454163-0002
Compressor Trim .50
Compressor A/R .45
Compressor Inlet ID 1.575"
Turbine A/R .64
Turbine Outlet 2.34" ID

All of the above seems pretty similar to turbos from kits that are offered around the internet.

Here is one of these for sale. Has many specs and rebuild p/n as well as a small picture.
1998- New Holland Agricultural Tractor TA2505 Turbo 454163-0002

A little about the OE application
Came on New Holland and Case tractors with 90 - 120 crank hp
Engine was 3.0L, 3 cylinder, 2300 rpm redline

This is where I start to get confused. The static flow of that engine is 6900 L/min and the static flow of my 1.8 is 12400 L/min.
At almost twice the flow rate of the OE application are there going to be balance issues? Can the bearings and seals handle those increased speeds?

Building a turbo miata around a random cheap turbo you found is a horrible way to do it.

So where's the parts list?

rule number 1. Never base your build around some random turbo.

get a standard s13 t25 from an sr20 and enjoy readily available hot side parts and great spool.

or try to make this random tractor turbo work, spend thousands on custom ewg manifold and downpipe. And probably give up mid way and never have a turbo miata.

A diesel turbo is not the same as a gas turbo. it will die.

tiny is correct:

Turbine Wheel 435354-0010 (Ind. 53.1 mm, Exd. 38.5 mm, 9 Blades)
Comp. Wheel 434541-0001 (Ind. 34.6 mm, Exd. 49. mm, Trim 50, 6+6 Blades)


and it's going to requite a custom manifold, with a custom EWG, with a custom DP that you wont be able to use with anything else...

I wouldn't call that turbo random. I gave you as much information on it as I know. Is there something not listed you would like to know?
Somehow I knew that I was going to get an sr20 comment. We don't have those here, and the very few that we do are factory n/a. There is no chance of sourcing a local used sr20 turbo.

This is what I am interested to know. What is the difference, what will happen? All the my limited turbo experience is with diesel engines from equipment.

so buy a brand new one from china for $120.

Please elaborate. Lets take the ever popular turbo from the SR20DET and compare it to the one that I have.

I realize that I would need a custom manifold, EWG, and custom exhaust. I was planning on tackling most of that myself. I have been working on manifold ideas for a while, even drew a few in Inventor. I had this crazy idea about using square tubing because I think its easier to work with. I drew one up for fun anyway. Then I found out later that the exhaust gases speeds really suffer in the corners of the tubing. Not the best flow characteristics when you are trying to drive a turbine.

Cant find SR20's around you? Rust belt, as in, central USA? you make it sound like your in Ireland.

If you were planning on making all of your own parts, mani and dp included, then by all means, use whatever turbo you want.

You want easy, fairly cheap, extremely available parts, use a GT2560r.

if you have a 1.6L the sr20 turbo spools pretty poorly. it's easier to get specs off a 2554 -- which is the smallest turbo I'd want on a miata.

compressor:
gt2554 in: 42mm ex: 54mm
gt2252 in: 40mm ex: 52mm
gt2052 in: 38mm ex: 52mm
ta2505 in: 34.5mm 49mm

turbine:
gt244r in: 53mm ex: 42mm
gt2552 in: 50mm ex: 43mm
gt2052 in: 47mm ex: 40mm
ta2505 in: 53mm ex 38.5mm


the gt2052 has a max flow of about 225cfm or roughly 225hp -- basically you'll have a crazy peaky turbo that will make a bunch of torque between 3 and 4k when the cam hits and then run out of steam instantly. and then the turbo will burn up due to the EGTs.

Ireland has a better selection of Imports than I do. I live in a very rural area. There are next to no sporty imports. One might see the occasional Neon SRT4, but that's about it. No one even knows what a Miata is, might as well be a kit car. Its all about diesel trucks blowing smoke, which I could rant about for hours...

Ok, this is helping to clear things up. I am taking this to mean that the cold side is way too small for the Miata engine. I wanted to get the turbo out of the way before I started listing other parts. Looks like I have several things to reconsider before I move forward.

Not to sound like a jackass but you know ebay exists right? You type in S13 T25 and youll have a bunch of options. That tractor turbo is poorly sized for your miata, sure it would be neat to use it but the end result will not be what you want. The guys and gals on this website have a wealth of knowledge listen to them.

hey! I need that turbo for my 7100 kubota!

I have one of those too, has mowed my yard for the last 17 years. It didn't have enough power so I had the fuel pump turned up, now it is plenty stout.

Would be really easy fab it all up for a turbo. I wouldn't know how to tune it though.

Have you seen this?
Turbo B7100 - OrangeTractorTalks - Everything Kubota

super easy. retard fuel timing, limit boost to 5psi. I hear it chops 2Ft. tall grass without slowing.

Dude, so you're saying both USPS and UPS have no idea how to make it to your house?

I live in the middle of no where West by God Virginia,and had no issues, that's a horrible excuse .

I live in a large city, and i don't think i've ever purchased more than 3-4 parts for any of my Miatas in total, in person.

yeah, who wants to meet up with some weird Miata person, in person. Yuck