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Z31 VG30E to VG30ET swap list

This question comes up so often it deserves its own spot: "I bought a Non-Turbo Z and I want to go faster. How can I make it faster for cheap?"

The truth? Doing a turbo swap—or adding a turbo to your non-turbo engine—is the quickest and cheapest way to make real power. Using stock Z31 turbo components and a boost controller, you can see 300+ hp.

Before you start, you should have already located a parts car (recommended) or gathered everything needed for a turbo conversion. Sourcing all the little pieces is often the biggest challenge!

Here’s what you’ll need to convert an N/A Z31 to turbo. Grab these from an 84–87 Turbo Z31 (T3 turbo) or 88–89 Turbo Z31 (T25 turbo):

Main Parts List

Pro Tip:

If you are turbocharging an ’84–’86 non-turbo, you’ll also need the alternator mount, tensioner, and a longer belt (the alternator mounts on the passenger side instead of the driver side).

Pro Tip:

Using a Pucker Factory Turbo Relocation Pipe? You won’t need the stock crossmember or intake piping—just plumb the turbo with custom pipes. Note: You’ll lose the air conditioner compressor with this setup.

Pro Tip:

Removing your engine makes this swap much easier. The crossmember and driver-side exhaust manifold need to be swapped—doing this inside the engine bay is possible, but it takes a lot more effort.

Fuel System and ECU

Warning:

Do not try to run a turbo on a non-turbo fuel system! The fuel maps and injector sizing are way too lean for a turbocharged application—doing so will quickly damage your engine.

Pro Tip:

The easiest way to relieve fuel pressure is to disconnect the connector under the hatch carpet to the fuel pump, then crank the car until it doesn’t fire.

You can now remove the full air Intake from your Z from the MAF (Mass Air Flow) Sensor to the lower intake manifold. This includes the upper intake plenum and throttle body. Make sure you are careful when removing the upper plenum as there are two coolant lines that attach from the lower intake to the upper plenum. One on the Right (US Passenger) side near the rear of the intake and the other to the throttle body.

Being careful, disconnect all the wiring harnesses from the different sensors on the plenum (IAC, EGR solenoid, TPS, AAC, etc). Mark and label the connectors and vacuum lines as you go.

You will likely need to remove the EGR valve from the intake plenum as it is likely the EGR tube will be frozen and not want to budge. Heating it may help break it free if you do plan on disconnecting the tube from the EGR valve or exhaust manifold.

The upper plenum is held to the lower manifold by 5 hex head bolts under the plenum cover.

Once you have the upper plenum out of the way you can see the fuel injectors. Before doing anything take some rags or tape and fill or cover the intake manifold openings to protect it from collecting anything. Now you can Unclip the fuel injector clips with a pick and pull the connectors off each injector. **Note: Now would be a good time to rewire the injector harness to factory specs as you will notice the injectors all piggy back off one lead per side.

Injector manifold removed from Z31

Now that the wiring is out of the way, you can remove the fuel lines from the fuel rail and the FPR (Fuel Pressure Regulator), and unbolt the two 10mm bolts that hold the regulator onto the lower intake manifold. With this disconnected, remove the Phillips screws that hold the injector hold-downs to the manifold and carefully lift the whole rail off the lower intake manifold.

Installation of the turbo injectors is the reverse of removal.

Since you upgraded the injectors to turbo 260cc units, you now need to swap the ECU as well so the fuel injectors and fuel maps match. This is easily done by swapping the ECU behind the right (US passenger side) kick panel. It is held in by a few 10mm bolts. Remove the bolts and disconnect the connectors. Installation of the Turbo ECU is reverse of removal.

Crossmember replacement

Replacement of the front crossmember is needed if you are not planning on using a turbo relocation pipe, as the turbo sits where the non-turbo left motor mount is located. This is easily done by jacking the car up along the frame rails (with the engine removed) and supporting it with jack stands. Next, remove the four (4) 10mm bolts that hold the power steering and AC lines to the crossmember.

Once these are removed, disconnect the control arms by removing the 22mm nut and bolt holding them to the crossmember. These could be tight or seized in the control arm bushing, so you may need to use some penetrating oil.

Now that the control arms are disconnected, you can disconnect the steering rack mounts by removing the four (4) 14mm bolts holding the straps to the crossmember. Make sure you do not mix up the sides, as they are different for the shape of the rack bushings.

Finally, secure the steering rack on a jack stand so it does not move, and then remove the four (4) 17mm nuts holding the crossmember to the chassis of the Z31.

Crossmember bolts location

Below is a picture of the differences between each crossmember:

Z31 crossmember differences

Oil Pan and Oil Feed

Turbo oil pan for Z31

To turbocharge your Z31, you'll need to swap over to a turbo oil pan or add a bung on the side of your non-turbo oil pan for the turbo oil return.

  1. With the engine supported on a hoist or stand, remove the dip stick and drain all oil from the engine.
  2. Remove the 10mm bolts on the outside edge of the pan. Once all bolts are removed, gently use a flat screwdriver to break the gasket seal—the pan should come off easily.
  3. Replace with the turbo (or modified) oil pan using a new gasket. Note: 08/84–01/87 models use a full oil pan gasket, while later ’87 and up models use a 2-piece gasket with black RTV sealant to seal the pan to the engine.

⚠️ WARNING

DO NOT INSTALL THE DIP STICK BEFORE INSTALLING THE OIL PAN!

The Z31 oil pan has a guide built in for the dipstick. If you do not remove the dipstick before installing the oil pan, you will bend the dipstick and it may be chewed up by the crankshaft counterweights, sending shards of metal into your oil and causing engine damage.

Once the pan is in place, remove the plug in the lower front (driver's side) of the engine block—this is where your turbo oil supply line attaches using two crush washers and a banjo bolt. The oil feed line will bolt right up to the block with its bracket.

You can now also move the driver side engine mount to the turbo location at the front of the left (US Driver) side block. You will see two holes just above the oil feed hole you unplugged.

Exhaust Manifolds

The next critical step in your turbo swap is the exhaust manifold. Start by soaking each left (US Driver) side manifold stud and nut with penetrating oil to break up any rust. Do the same for the two bolts and one stud on the crossover pipe.

If you find any broken studs (a common issue), use a reverse drill bit or an “easy out” kit to remove them. Many builders upgrade all the studs to larger 10mm x 1.25 units by drilling and tapping for the VG33E (Nissan truck) spec hardware.

Z31 manifold studs

Once you’ve removed the non-turbo manifold, you’ll notice the placement of manifold studs is different between turbo and non-turbo heads. Fortunately, Nissan pre-drilled and tapped the heads for both layouts—just swap the studs to the correct locations.

Pro Tip: Use a Victor Reinz multi-layer steel exhaust manifold gasket—they’re much more durable than fiber gaskets.

With the exhaust manifold installed, bolt on your turbo. This is also the best time to install the turbo oil drain, as it’s easiest with the turbo off the car. Once mounted, connect the oil feed line to the top of the turbo housing. If you have a water-cooled turbo, attach and plumb those lines up to the throttle body and manifold locations.

Engine Installation and Finishing

Go ahead and install the engine using an engine hoist, and bolt the mounts into their new locations on the crossmember. Once the engine is secured, begin reconnecting all wiring, coolant lines, and heater hoses. Install the upper plenum next.

At this stage, you have some choices—either run the stock intake pipes or fabricate a custom intercooler setup. You’ll also need to complete your exhaust, since it now ends at the turbo elbow. For a bolt-on solution, check out CM Performance Exhaust, or have a local shop build you a system.

Pro Tip: Plan your exhaust and intake upgrades before finishing assembly—test fitting saves a lot of headaches!

Once everything is in place, fill the engine with oil and coolant. You should now be ready for first startup! If you have idle issues, you may need to adjust the idle control wiring.

Final Information

There are always a few things that usually are asked when doing this type of swap, I will try to answer them here.

  • Will this hurt my Non Turbo motor?
    No, as long as you keep boost at reasonable levels for your setup, you should not have any issues.
  • How much horsepower will I make?
    This varies depending on your installation. Stock turbo cars made around 200hp at the crank. With the higher compression NA motor, you’ll likely see more, especially in the lower RPM range.
  • How much boost can I run?
    If you use all stock plumbing and no intercooler, do not exceed the stock boost level of 8psi on the T3 turbo (stock wastegate setting). Boost controllers aren’t recommended unless you add an intercooler—then up to 15psi is safe on a stock T3.
  • Will my car be legal?
    If your build meets local emissions laws, you should be fine. Most Z31s now qualify as classic cars and may not require emissions testing, depending on your location.
  • Can I run AC and install an intercooler?
    If you can fabricate custom piping, you can route plumbing to clear the AC compressor—just like the old Spearco Intercooler kit did. It’s possible to have both.

Sources Used