Turbocharging the Nissan MR20DD Engine! Part one, the External MR20DD Architecture

Our latest endeavor in the field of modding cars has been to revisit what was one of our favorite cars of all time, the Nissan Sentra.  If it was not for the original Sentra SE-R there would be no MotoIQ, as that car was the one thing that brought all of us together to become friends, and then business partners a long time ago. When the Sentra went away from the SE-R moniker and the SR20DE engine we lost interest in the newer Sentra variants, as they became bigger, less sporty and less performance-oriented.  The newer Sentras were designed around practicality and value more than being sporty, and these offerings were less interesting to us. It had gotten to the point where we didn’t even know what the newer Sentras were like, until Martin rented one for a vacation road trip and we all got to take a good look at it. We were all very pleasantly surprised.  The latest Sentra had class-leading interior and telematics, decent handling, a good ride, and good brakes. The only disappointment was the less than class leading performance from the MR20DD engine and the CVT transmission.  Even then, the engine was smooth, quiet and good enough to do the job well for a practical economy sedan.

The road trip rental Sentra was a base model, but it came with all the goodies we could want. Power everything, CarPlay, and a pretty robust cruise control. You set your speed, following distance and relax. The CVT and MR20DD combo yielded an average of 38 MPG on our 2,000+ mile road trip! Perfect for what we needed, but if we were to buy one we would sure love if it had more power.

We got a request through Nissan Motorsports to see if we would be interested in building a turbocharged version of the MR20DD. We jumped at the opportunity to challenge ourselves to see if we could get the value based Sentra up to snuff in a performance-sense.  We would have many challenges in the road to do so.  First, was the transmission. We knew the Nissan CVT would not be up to containing the power and torque of a turbocharged engine, and that enthusiasts basically disliked it with a passion.  Fortunately, the team found that the Canadian Sentra was available with a 6-speed manual transmission – so one of those was ordered up immediately.  Second, there was no tuning solution available for the car and no one in the aftermarket was interested in supporting the project in the slightest.

Once again a solution came from Canada where Nissan Canada has a Sentra racing seriesa . The engine package has an engine management solution run by Motec ECU. The spec’ed system could talk to the Nissan CANBUS and powers all of the cars in their series. Suddenly the project idea became quite viable!

The MR20DD is actually a joint effort by Nissan and Renault. It is also known as the Renault M5R and can be found in cars like the Megane and the Espace, as well as the Sentra. The direct-injected engine displaces 1997cc and makes 149 hp at 5600 rpm and 146 lb/ft of torque at 4400 rpm. Although this isn’t particularly impressive for today’s engines, it does make more power and torque than the beloved SR20DE ever did and manages to move the much bigger and luxurious modern Sentra from zero to sixty in a decent 8 seconds. That is only slightly slower than the B13 SE-R’s time of 7.6 seconds in a much larger and luxurious car that still delivers better fuel economy. Lets take a look around the outside of the MR20DD to see how it might adapt to turbocharging.