The Turbo

We all want to change the world. But when you talk about destruction, don’t you know that you can count me out. Don’t you know it’s gonna be alright?

So the most common asked question is what turbo do I need? I will say that a small turbo will spool fast and produce good boost but will most likely need to be rebuilt occasionally because of the very high rpm.

A larger turbo is more reliable but is harder to spool. A turbo forces air into intake and will lean things out if you don’t have the extra fuel needed. It seems a lot of guys like the gt1544/48  and I guess its a good place to start.

Even some competitive tractors running GT 12. Try to find good used turbos that are brand names instead of a new china turbo. If you put a boost gauge on both sides of turbo it will give you an indication if your setup is balanced.

You should have close to the same pressure on both sides. Most guys lock the waste gate in closed position to maximize the boost. I would shoot for a boost of around 30 to 45 psi.  

You will need to make an adapter from turbo to the exhaust manifold. The best is to place things or mock it up first and measure how high and what direction you want it to be. Your best bet is to take your manifold and turbo to a machine shop with your measurements and have them make a billet adapter. 

Very often the adapter is going to be three bolt to four or two bolts to three. Try to keep oil drain facing downward. You can get your oil feed off the oil pressure sensor fitting and I have in some cases put the oil drain return into the dipstick tube.

Most turbos you can spin the output housing to suit your needs  by loosening a clamp and drilling a new hole for pin lock. Others just loosen clamp and spin it. The rules say you must put rods or bolts  in a x inside your exhaust output. I drill and tack weld bolts this is to stop parts from flying out in case of a blow up. I like to drill and tap the adapter for the egt probe. Normally its a 1/8 pipe thread.

Make sure you use good silicon hoses with good clamps stay away from rad hoses and rad clamps. I can’t count the times I have seen guys two thirds down the track and bang hose lets go or clamp lets go. 


There are a few different exhaust manifolds that exit at different angles. I do not like the turbo manifold that Kubota uses being that the exit is much smaller than the non turbo manifold.

I guess they are looking to increase velocity. Cranking at 7k rpm I think the non turbo exhaust manifold is the better choice. Here you can see the difference. The three bolt is turbo model and 30% smaller hole.


Some might say the neck on turbo model gives equal pipe length and if you agree you can do some grinding and open it up some but it won’t be as open as the other model

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