MR16DDT Port Injection Conversion

Now that we have successfully done a port injection conversion, we want to share that information.

A few disclaimers before we continue:
-This is not EPA legal. If you do this, it should be for RACE USE ONLY.
-Custom made parts are REQUIRED.
-This is not cheap. Labor time from a fabricator MUST BE included if you price this out.
-You need serious automotive electronic know-how to do this. This is not a weekend mechanic type project.
-Repeat disclaimer 1.
-Some information below is JUKE SPECIFIC ONLY. So help me god if I see one "there's work around to that on this car" I will lose my ****.
-We will not be discussing the benefits of the tuning system used.
-This will NOT work for V2's. Sorry folks, too many electronics in there.
-We have not tested this with a CVT. But. Really. Get a six speed.
-There will be very limited photos for this, we will take more the next time we do a swap like this.

Why port injection?
Direct injection is the bet sort of gasoline injection you can have. No doubt. It's fantastic. Unless you're building something high powered, or for motorsports.
DI systems are extremely hard to upgrade and come with loads of performance limitations. One such limitation is rev limits. We have shown that 9000+ RPM revs are possible on the MR16DDT. The issue with this is that the High Pressure Fuel Pump (HPFP) cannot operate at those revs. It cavitates really really bad north of 8400 rpm. After a pull at these higher RPM's you have to let the car sit for 10-15 minutes to let the fuel settle before you can even run it again without serious misfiring. These are little engines. To run large turbos to make serious power, or to run small turbos at low boost and make decent power, they need to rev out. B16a's anyone? So, by ditching the HPFP you can now rev to your hearts content.

Another limitation is injector/pump size. As of right now, there is no means of upgrading the HPFP or fuel injectors to bigger ones. This means the power you make is limited by the flow of those parts. You can add systems like AUX fuel or meth injection to get around this limitation, but those add more complexity and have their own potential issues. Port injection is easy to upgrade. In tank pumps are easy to upgrade, and you can throw a digital dart on google and land on a company selling large fuel injectors.

The final limitation is fuel type. On DI it is very very sketchy to run anything other than normal gasoline. DI systems do not like ethanol. Even the 10% mix in some areas can degrade the DI system components over time. Because of how the ECU in the Juke works, there is also no means of running flex fuel of any kind. You can tune the car for e85. But. What happens when you run out of fuel somewhere that doesn't have e85? Or the pump you get e85 from is not actually pumping out e85, and its actually e70? We have seen samples from a local gas station that sells e85 that show wildly different ethanol contents. It goes as low as e55 some months and as high as e90 others. Not very safe to be just tossing in whatever mix into a car without a flex fuel system. Doing port injection means you can run practically any fuel. M1 race methanol fuel? Sure. E85 flex? Sure. Just set your fuel system up for it and your good to go (tuning changes required obviously).

Why the MRA8DE and not the MR18DE?

The MRA8 uses a duel VVT system. The MR18 does not. You will see as your read why this matters. The MR18DE head will fit the MR16DDT block. But the timing cover has to be modified to work. We did a hybrid MR16/18 in a cube recently. More 18 than 16, but that's a separate story. You could do a MR16/18/A8 hybrid, but it would require a custom head gasket. We are about to release forged internals for the 18, so you could have a big bore 1.8 with forged internals if you wanted. Tangent over.

Now on to how to do this swap.

Parts You WILL NEED.

-MRA8DE Engine (top to bottom, whole thing, with wiring harness)
-MR16DDT Engine (at least the bottom half, unless your using your engine as a donor)
-MRA8DE Intake Manifold Flange (Custom)
-MRA8DE Exhaust Manifold Flange (Can cut the one off the oem header if need be)
-MR16DDT Turbo Manifold (unless you are making a custom tubular one)
-MRA8DE Gasket Kit
-MR16DDT Head Gasket
-MR16DDT Head Bolts/Studs
-Oil Filter Sandwhich Plate Adapter (for an oil feed line)
-3-4ft Long Oil Feed Line With Fittings
-Standalone ECU of your choice (we used a Fueltech FT550)
-Loads and loads of quality wire
-Un-pinned automotive grade connectors
-ECUTEK tuning software (or uprev if you really want it)
-Threaded Hall Effect Sensor
-1.5k Resistors
-Knock Light
-AEM Eugo wideband gauge, or some other wideband system with a 5v analog out.
-A small 1/8-1/16" thick piece of metal.
-Various piping and components for fabricating an intake manifold.
-Supporting mods for desired power (injectors, fuel pump ect.)


The Easy Part:

The MRA8DE head bolts right onto the MR16DDT bottom half. You can do this a few different ways.

If you want a larger displacement engine with higher compression, you can swap out the MRA8DE upper/lower oil pan with the MR16DDT one. Downside to this is you will not be able to upgrade the internals, so your power will be limited to whatever a A8's internals can handle. You will also need to add a return port for the oil return on the turbo, which is easy enough to do.

If you want to keep the MR16 engine, use the MRA8DE cylinder head and timing cover with the MR16DDT block and oil pans. Doing it this way means you can use upgraded MR16DDT internals and retain the lower compression for more boost.

The reason you are using the MR16DDT upper oil pan for either of these is because of the crank sensor location. On the MRA8, the crank sensor is behind the engine (exhaust side), and the 16 has it in front of the engine (intake side). This matters when it comes time to make the oem ECU happy.

While you're doing this, it is highly suggested to do the following upgrades, regardless of performance goals. Swap the MRA8 valve springs out for supertech ones, so you can safely rev to the moon. Use upgrade head studs and head gasket to future proof your engine. Replace valve seals. Check valve lash.

For a turbo oil feed you will need to go old school. The A8 does not have a port for the feed line. The spot for it is in the casting, but you will need to machine out the block off and add the threads. You risk filling the oil passage up with debris doing it that way. The way we did it was to use an oil sandwich plate adapter. We then ran the oil feed all the way around to the turbo. This is typically how you add an oil feed to a non-turbo engine, so it works fine.

The Harder Part:

This is where the labor time starts to come in. We will be making a few assumptions from here on out: You will be using an OEM style turbo (mamba ect). You will be using OEM style intercooler piping (stock or otherwise). You will be retaining a diverter valve.

To do this swap you will need to make a custom intake manifold. The MR16DDT one will not work or fit. The OEM style A8 one will not work with OEM location turbo components. It also has two separate runner systems in it that make it a nightmare to work with. We make ours from aluminum. It's not rocket science to make a working manifold. But it does take time. We spent 20+ hours on ours, including doing the math for runner length and allowing for time for parts to cool to prevent warping during welding. Hauling ass, you could make up a manifold in a workday. But it wouldn't be the greatest. You manifold will need to fit around the oem part constraints, not the end of the world, just adds complexity to the design. You will quickly see how Nissan/Renault arrived at their design when you make your first intake manifold for one of these. You can either add several ports to the manifold for things like vacuum reference and evap systems, or you can run a vacuum block to simplify it all.

The turbo manifold part is where you have a few options. The MR16DDT manifold will not bolt up to the A8 head. You can either make a custom tubular/log manifold, or you can make the 16 manifold adapt to the A8. The oem 16 manifold can be milled down to remove the mating surface, then the A8 flange can be welded to it. The flow transfer can be cleaned up with a Dremel. You will want to add some sort of bracing between the cast steel manifold and the mild steel flange somehow, to make sure the full weight of the turbo is not on the main welds. Cast welds can be brittle under heat. But it is do-able. If you do it this way and retain the OEM turbo location, you can use off the shelf intakes and downpipes. Otherwise, custom will be required.

If you are using the oem turbo piping, the A8 valve cover will not work for you. The 16 valve cover can be used, the front left corner will need to be cut and a large washer will need to be used on the bolt that goes there, so that pressure is applied to that area when tightened. The valve cover gaskets are the same.

The Hardest Part:

This is where 99.9% of people will give up on trying this. Wiring and electronics.

Like before we will be making a few assumptions: You are trying to avoid having a CEL, not for emissions reason, but just because you just don't want one. You want to retain all OEM functions, such as power steering, ABS, climate controls, ect. You are okay with not having traction control fully working. Your insane.

We will be using a Fueltech in this example, but any standalone with an AC button feature will work. The standalone MUST be capable of drive by wire throttle, which eliminates most of the cheap ones sadly.

Things we need to add to the engine: a third cam position sensor, a second knock sensor, a boatload of wire.

We are adding a third cam position sensor for one reason: the OEM crank sensor is a mirrored 36-2-2, which means it needs a single cam pick-up point to determine cylinder position. The OEM cam signal plates have 4 (exhaust cam), and 10 (intake side). If you modify a cam signal plate, you will not be able to get rid of that pesky CEL you don't want to see for reasons un-related to emissions testing. To add the new sensor, you will need to modify the engine mount and the upper timing cover. Take the cover off to do this, obviously.

You will need to drill and tap around this (pictured below) area for your full thread body hall effect sensor that you got.
Gas Auto part Nut Metal Titanium

Once you have done that, you want to rotate the engine to cyl one TDC, then rotate it backwards 40-60 degrees. Put the upper timing cover back in place and make a mark on the exhaust VVT gear. Take the cover off. Now you need to very very CAREFULLY tig weld a piece of steel in the sport you marked on the VVT gear. The metal has to be as long as the diameter of the sensor being used, at least as wide as 1/16", and at least 1/8" tall (sticking up from the surface). When the metal is on, good and solid, place the cover back on and check for any rubbing by rotating the engine. Clearance the casting as needed. Once you're done with that, fully install the timing cover and hall sensor. Be sure to lock the sensor in place at an appropriate height for it to read the signal marking you added.

Now, modify the engine mount to clear the hall sensor you added. I recommend doing a full slot, so the mount can be safely lifted off of the sensor if need be. Don't remove so much material that the mount becomes structurally compromised.

Now for the wiring. The OEM ECU MUST see the following signals: Crank sensor, both cam sensors, coolant temp, oil temp, oil pressure, throttle position, pedal position, MAP Sensor, MAF sensor, Oxygen Sensors 1 and 2, VVT solenoids.

This is going to be complicated, so follow along best you can. I can explain more if need be.

The standalone must use its own 5v output and grounds for sensors. You cannot use the 5v and ground the oem ecu uses on the sensor that will be shared. This is done so the standalone can monitor the 5v being sent out and compare it to the received signal to check for noise and other issues. The oem ecu just needs to see a return signal, and if it does, it is happy. So.

On the crank sensor, leave only the signal wire going back to the oem ecu. The 5v and ground are to be supplied by the standalone. Tap the standalone signal into the signal wire so that it is shared between the two ecus. The coolant temp and oil psi sensors do something similar. The 5v wire must come from the standalone ecu, and the signal wire needs to be shared. On the MAP sensor, we only need the temp part of the sensor sent to the standalone. So the 5v and ground for the entire map sensor must be supplied by the standalone, and the temp wire needs to be shared.

You can optionally just add new oil pressure and coolant temp sensors to the car to avoid having to touch those. The sandwich plate work for the oil PSI and tapping the thermostat housing for a second sensor is pretty easy.

For the throttle body, wire the throttle to the standalone as required. The TPS wire needs to be sent to the oem ecu, so that should be the only shared wire. For the pedal, the power and ground wires need to be standalone provided, but the two computers need to share the position sensor readouts.

For the coil packs, you can do this one of two ways. You can allow the OEM ecu to retain control over the ignition system, or you can give it to the standalone.

Benefits of the OEM control: OEM reliability. OEM Knock Control.
Benefits of the Standalone Control: Race features like two step and timing by time for racing can be used.

Either way, best to leave the OEM connectors alone so that diagnosing ignition issues is easier, as the oem system can help tell you if you have a bad coil or bad standalone wiring by just plugging the oem harness back in.

If you are using the standalone to control the ignition, leave the oem power and ground to the coils. This reduces the amount of wiring that needs to be done for things like coil power relays and such.

For the open injector plugs: safely install the 1.5k resistors across the connectors. This simulates the injector load and makes the oem computer think the injectors are working. If you don't care about the CEL, you do not need to do this. If the 1.5k resistors do not work as intended, measure the resistance of your injectors and get an appropriate size resistor.

For the AC, tap into the AC trigger wire. This will be used to tell the Standalone that the AC is on so it can make the proper adjustments to throttle, fueling, and timing.

If you are using the standalone for the ignition, you will want to add a knock light. This is mostly for tuning purposes, but it's a great tool to have in the car to monitor its health.

We tested stacked knock sensors and found that as long as the knock light sensor is the outside sensor, it will work as intended. Use a stud, not a bolt, to fasten the two knock sensors together onto the engine.

Wire up the new cam sensor and injectors as required by the ecu.

Wire up the boost control solenoid as required by the ecu.

Because the oem key system is still working, you only need to add a means of turning the ecu main power and giving the injectors power. So, two relays. A simple toggle switch can be used to turn the standalone on, or if you want, find an acc powered wire to trigger the standalone to run. The airbag fuse is a great one, as it does not lose power when the vehicle is cranking (at least it shouldn't).

Optional wiring: you can add a third clutch switch, so race features in the standalone can be used. Mounting a microswitch is pretty easy, as the whole clutch bracket comes right out so you can drill holes or weld on tabs. Since the OEM Traction control will not work, as it uses throttle to reduce power, you can hijack one of the rear wheel speed sensors to give the standalone a wheel speed input for things like boost by speed, ect. The TCS light will illuminate on the dash if you do this. YOU CANNOT SHARE ABS SIGNALS WITH THE OEM ABS MODULE. We have tried this several times. To make it work you would need to make up a system that reads the incoming signal and sends its both ways instantly with the proper voltage. Doable, but tedious. You can add an in-line flex fuel sensor now. The ethanol lambda will piss off the oem ecu, and it will throw all sorts of o2 sensor related codes, but those go away with the use of regular gasoline.

Tuning Tips:

As you probably noticed, the oem computer retains control of the VVT system. Due to that pesky CEL you don't want to see for non-emissions related reasons, it has to be this way. So. You will need to do some tuning with ECUtek. In ECUtek, you can have your tuner disable all the codes that you can. Codes such as evap, VVT, Oxygen sensor, Injector, system too rich/lean, and misfire codes cannot be disabled. Again, this is just to avoid having the light on your dash. If you don't care, let that chrismas tree shine!

The ECUtek tune will need to max out the boost cut limit, max out the desired boost level, and set the target AFR's to match the ones in the standalone. If you are using the OEM ecu to control ignition timing: the torque tables will need to be changed as needed, this is the most annoying bit of using the oem system for ignition.

If for some reason, the oem ECU freaks out with all of this done; you will need to play with the sensors being used and the tunes to make it all work right. This is the annoying part of using two computers for one car.

Setting up the Fueltech is pretty easy. It takes a few hours. Fueltech tech support is fantastic and will remote in and do a majority of it for you if need be. They will explain every step to you as well if you want. Just make sure you have all of the inputs and outputs set up before you call. They can help you do that as well, but they have other people to help, so be courteous of that.

Other Information:

If you don't care about a CEL: instead of adding another cam sensor as shown, shave off three of the signal plate points on the exhaust cam, and use that sensor for the standalone. If you do that, then you can have the standalone also control the VVT. You should still let the oem ecu see the cam signal, even if it's wrong, just so the code it throws is not power/ground related. It can cause other issues. Also, you can skip the injector resistors if the CEL isn't a problem for you. The car will run correctly even if the ECU has injector power codes.

Systems controlled by which ECU:
radiator fans
Gauge Cluster

Fuel Injection
Ignition Timing
Throttle Control
Engine Safety's related to Oil PSI and Coolant Temp
Race Car stuff

Cost Breakdown:

This is a hard one to do. Your labor value may be different from ours. So. We will just put rough times down for everything. Costs of materials depend on location as well, so this will be a rough estimate. Used parts costs used for engines and manifolds:

-MRA8DE Engine $1000
-MR16DDT Engine $3000
-MRA8DE Intake Manifold Flange $50
-MRA8DE Exhaust Manifold Flange $50
-MR16DDT Turbo Manifold $100
-MRA8DE Gasket Kit $400
-MR18DDT Head Gasket $85
-MR16DDT Head Bolts/Studs $250
-Oil Filter Sandwhich Plate Adapter (for an oil feed line) ~$75
-3-4ft Long Oil Feed Line With Fittings ~$170
-Standalone ECU of your choice (we used a Fueltech FT550) $1400-$2000
-Loads and loads of quality wire ~$250
-Un-pinned automotive grade connectors ~$100
-ECUTEK tuning software (or uprev if you really want it) $300 license
-Threaded Hall Effect Sensor $115
-1.5k Resistors $.05
-Knock Light $350
-AEM Eugo wideband gauge, or some other wideband system with a 5v analog out. ~$220
-A small 1/8-1/16" thick piece of metal. $2
-Various piping and components for fabricating an intake manifold. ~$750
-Supporting mods for desired power (injectors, fuel pump ect.) $up to you.

Estimated total cost: ~$9267.05

$4400-5000 of that is a second donor mr16ddt and the standalone.

Times are based on someone who has not done this before, a professional will be faster. Times are estimates:

Engine removal/installation 8-12 hours
Swap Engine Parts 5-10 hours
Modify Exhaust Parts 4-6 hours
Make Intake Manifold 8-20 hours
Wire up ECU 20-40 hours
Modify timing cover 3-5 hours
Tuning 6-12 hours
ECU set up 2-4 hours
Cussing and crying 3-5 hours
Junkyard runs for broken connectors and sensors 100-200 trips
Troubleshooting 1-20 hours

Estimated time: 60-134 hours.

Final Thoughts:

This is an intense project to do. I am posting this information here for the sake of transparency. I highly doubt anyone will attempt to do this themselves. But this just shows the time and energy needed to come up with solutions for specific problems when it comes to making these vehicles competitive performance vehicles.