The Altima 2.5, the Sentra SE-R, and the Sentra SE-R Spec V all use the same QR25DE... Why the differences in power across the board?
The physical specs seem to be the exact same between the Altima 2.5 and the Sentra SE-R; yet the Altima 2.5 has 175 HP @ 5600 RPM and 180 TQ @ 3900 RPM, and the Sentra SE-R has 177 HP @ 6000 RPM and 172 TQ @ 2800 RPM. Is this just a difference in ECU? If it is just an ECU difference, I think the SE-R's ECU may be a 'bit nicer to have in the Altima because the torque comes on a little over 1k RPMs sooner, even though it is a 'bit lower in total ouput. Also, the peak horsepower is a 'bit better.
Also, it looks like the only difference between the Altima 2.5 and the Sentra SE-R Spec-V engines is the compression ratio, and possibly the ECU again... is that correct? Would it not be possible, then, to install the Spec V pistons in the Altima 2.5 engine, and swap over the ECU and have the same amount of power that the SE-R Spec V has? (200 HP @ 6600 RPM, 180 TQ @ 5200 RPM)
Just trying to understand what all can be done with these motors.
Hopefully NISMO comes out with some more performance parts for the Altima 2.5 soon, lol.