Turbo Question

Fits 922A/B with D311 engine.

Would this be too small to retrofit onto a D47U? I have the fabrication skill to install it. If I were to install it what adjustments will I need to make to the fuel pump? Thanks for the help, I'm not trying to gain 50 horsepower, I would just like to get a small increase. Thanks for the quick reply.

I don't know of any of the old non-turbo tractors that would really roll out the smoke under load (unless they were burning oil at a prodigious rate), so without a fuel rate increase, you are unlikely to gain much if any performance just from adding any turbo. I know MBcat who used to maintain the database of serial numbers and owners on the ACME website used to recommend removing a torque spring shim or two on the old tractors to gain a little rack travel and increase performance/smoke even without a turbo.

That turbo was used on the D311 (actually called a D320 as it was setup with the turbo in the 922 loader etc) at similar horsepower to the D315, so my guess is it is not very much too small. Probably would spin up faster than a larger one and give a quicker response. Since you already own it, you might try it and not be out much if it didn't perform.

How well does the D4 cool now?

A turbo that's too small for the engine will actually make better low-end boost, & overboost at full RPM. (More exhaust volume spins it faster)...That's the reason for a wastegate, you can use a smaller turbo, & the wastegate dumps exhaust at high RPM. Makes a flatter boost curve & helps the "turbo lag".
I've turbo'd a couple JD 4240 tractors that had to actually have the fuel turned up a little, they burned so lean they ran hot... not a whiff of smoke except at startup.
You don't say where you are, if you're above 5000 ft., a turbo will help both smoke & power w/o turning up the fuel. Like cc said, the size of the engines are close enough you might be OK, it's worth a try. Unless the turbo you have happens to have a wastegate, then you're good to go...

Big difference in rpm's. The 7U's range from 1525 to 1800 rpm to make their rated hp. The 922 59A makes 2400 rpm to make it's rated hp.

I am only about 200 ft above in NW Oregon, anyone have any recommendations for setting the fuel injection. Also, at this current time it rarely smokes under load and never gets over 175 degrees.

If it's sized close to right, don't touch the fuel. Just install the turbo and look for an improvement at the torque peak, which on your D315 might be maybe 1000 rpm? If that plays ok, then adjust the fuel for a small hp increase - check it on a dyno.
The correct way, though, is to figure out your engine's air mass flow, and then select a turbocharger with a map that covers that point and that has remaining capacity to handle the air flow / pressure for the extra HP that you're looking for.

I think that I was going to match a turbo to the d315 engine ,it would be a turbo that came off a 955h .Its probably going to be a costly mistake to put a turbo on a old d315 in the long run or short run !
Why not frist increase the rack stting .005 to.010 ,and increase the rpms 50 or 100