“Impressive” is a massive understatement when referring to the capabilities of Nissan’s R35 GT-R. With highly-tuned factory-engine/factory-turbo R35s breaking into the 9s and highly-modified, big-turbo/built-engine variants in the high 7s and low 8s, the performance potential is simply unbelievable. Today, trap speeds indicate that some of these GT-Rs are putting out over 1,800 horsepower to the ground. The vehicle that was touted at its launch as being “un-tunable” is now the recipient of some of the best-engineered aftermarket products in the world. While not a platform that can fit into everyone’s budget, those that do purchase the GT-R seem intent on serious performance increases. Recently, MoTeC decided to get serious about the R35 GT-R with its latest-generation of engine management specifically configured to plug-in and support the vehicle. While not the first plug-in ECU to market for the R35 GT-R, the MoTeC offers some unique features while doing what many other ECUs claim they do, without the hiccups.
Text and Photos by Michael Ferrara
MoTeC Expands Focus
While the MoTeC brand is familiar to many, MoTeC focused all of its product line on professional motorsports teams during its first 20 years of operation (from 1987 through 2007). For those teams, having to build a custom motorsports harness for the vehicle was expected. An absence of plug-and-play ECUs and premium pricing for the product/option packages presented barriers to entry for many hard-core performance enthusiasts that may have considered MoTeC’s offerings.
In 2007, MoTeC released plug-in solutions for the EVO IX and WRX based on its M800 series of ECU. While the product worked extremely well, the customer base was limited and MoTeC’s marketing to the privateer enthusiast was pretty much non-existent. Fortunately, MoTeC didn’t give up on this lukewarm reception by the performance aftermarket. Instead, the potential of the R35 GT-R inspired MoTeC to put its latest generation of technology behind a complete plug-in, stand-alone solution for the vehicle. Hence, the MoTeC M1 R35 GT-R Plug-In ECU system was born.
While MoTeC conquered the drive-by-wire and multiple camshaft control with its M800 series years ago, the R35 GT-R presented additional challenges above and beyond the M800’s capabilities. Nissan’s complex and intertwined CAN bus integration of the factory Engine Control Module (ECM) with the Transmission Control Module (TCM) and Multi-Function-Display (MFD) meant that a plug-in solution would need to do much more than just run the engine.
MoTeC sought a plug-in ECU solution that would have full integration with all the factory control systems without compromise. In this way, the MoTeC ECU could send commands and receive requests from the factory TCM or other control systems. In addition, the factory Vehicle Dynamics Control (VDC), which provides traction control, would also communicate and cooperate with the MoTeC ECU. Even creature comfort controls like cruise control would be commanded by the MoTeC ECU.
M1 Takes Charge
The solution to the challenges would be found in MoTeC’s latest-generation of ECU, the M1 series. The M150 ECU used in the kit not only communicates and commands all OEM systems, but it also allows superior engine control.
For those needing 12-injector support to meet high-horsepower demands, the MoTeC M1 Plug-In ECU delivers. Each stage of injection can use different flow-rate injectors and the transition is fully programmable to avoid hiccups caused by lean or rich spots when the secondary injectors first come online.
Better In Boost
While higher-flow-capacity turbos allow the engine to make double or triple the power output available with the stock turbos, these “big” turbos can be real lazy when launching the vehicle. The MoTeC system allows a “launch sequence” to be programmed that can build boost to a set level using closed-loop ignition-timing and ignition-cut control. So that the transmission’s clutch capacity (for whatever stage of transmission modification from stock to fully built) isn’t exceeded, the tuner can specify the engine speed (RPM) and engine torque limits at launch. The M1 limits torque through either drive-by-wire throttle control or ignition timing control to reach the target values.
When Tony Palo of T1 Race Development switched over to the M1, he noted, “On my first attempt setting up the launch control on the M1, I put in some numbers that I thought would be close. Right off the bat, it was the best launch I’d ever had in a R35 GT-R. This was on a closed road close to my shop, not on a prepped surface and it was still amazing. Other systems will require 20 or more launch attempts to try to get the launch RPM, boost pressure at launch and traction control working together. The fact that both the MoTeC M1 and the factory TCM are torque-based control systems means that set up was a snap, since they are both speaking the same language.”
Once the launch sequence is completed, the MoTeC M1 can then control boost with respect to the engine’s torque output. This allows various torque curve shapes to be created for optimized performance in different types of competition. The MoTeC M1 is able to measure torque due to its modeling of the engine efficiency, throttle body flow and intake manifold pressure. Pressure sensors before and after the throttle body, along with the intake air temperature sensor in the manifold, provide the necessary data to accurately predict torque output. Once the torque request maps are tuned, even the nastiest R35 GT-R can launch, shift, drive and behave like a stock vehicle.
If you are running your GT-R and road conditions change, the M1 allows the driver to have 10 separate levels of VDC control and 10 different levels of torque limit. The VDC control makes the traction control more or less aggressive based on conditions The torque limit control regulates torque output to 10 different levels. Optional 10-position switches are the only hardware needed to utilizes these limiters. An optional two-position switch is also available for those wanting to be able to switch maps on the fly.