Nissan 370Z Forum - View Single Post

ZBro16 · 01-23-2013, 10:34 AM

This is something I am starting research on but haven't yielded anything in a search.

In the event of a final drive swap (say Tomei 3.90 gears or Frontier 4.08 gears), it plays hell with the SRM (eventually - some don't see any issues while others see issues right away).

The SRM is controlled via the ECU using numerous calculations to be able to properly blip the throttle across the rev range at any point in the rev range during engagement of any gear in the gearbox. The ECU has to utilize some kind of equation to provide for this - the static numbers have to include the engine speed and the ratio of each gear, taking into account the final drive ratio, in order to properly calibrate the entire module.

This leads me to believe there has to be some way to unlock the SRM to tune it to be fully functional in the event someone decides to swap the final drive in a 6MT. Dare I say the module was developed in such a way that Nissan had this designed before a final drive ratio was even selected for the car, or my speculation is total garbage.

So, tuning gurus, is this something that is possible? Has anyone played with it?

01-23-2013, 10:34 AM	#1 (permalink)
ZBro16 Enthusiast Member Join Date: Nov 2011 Location: Huntsville, AL Posts: 370 Drives: A Z. Rep Power: 13	Tuning to calibrate SRM? This is something I am starting research on but haven't yielded anything in a search. In the event of a final drive swap (say Tomei 3.90 gears or Frontier 4.08 gears), it plays hell with the SRM (eventually - some don't see any issues while others see issues right away). The SRM is controlled via the ECU using numerous calculations to be able to properly blip the throttle across the rev range at any point in the rev range during engagement of any gear in the gearbox. The ECU has to utilize some kind of equation to provide for this - the static numbers have to include the engine speed and the ratio of each gear, taking into account the final drive ratio, in order to properly calibrate the entire module. This leads me to believe there has to be some way to unlock the SRM to tune it to be fully functional in the event someone decides to swap the final drive in a 6MT. Dare I say the module was developed in such a way that Nissan had this designed before a final drive ratio was even selected for the car, or my speculation is total garbage. So, tuning gurus, is this something that is possible? Has anyone played with it?