New Sentra SE R torque...

[Z BomB]

Hi guys, I was looking at the 07-08 Sentra SE R specs and noticed that the torque on the automatic se r peaks at 2800 rpm, where as the spec v peaks at 5200 rpm. Can someone explain how this is?

[gotak]

The engines are bit different. One runs on regular and the other runs on premium. Compression ratio are different too. They most likely tuned for max torque at that low speed to suit the CVT and for fuel economy. When I am rolling at 60 kph it's just going a bit above 1k rpm. At 120 kph it's like 2400. By the time I hite 2800 rpm I am doing 130 145 kph.

[Z BomB]

Oh so basically it's the CVT that helps with producing peak torque at such a low rpm. I was a bit confused before b/c I know that in the new SE R, Nissan put in a single stage intake manifold with short runners (I think) and that's great with high end power with sacrafice of low end torque. But it's the CVT that kinda helps restore that.

[Z BomB]

I just realized what you meant and that is that the car is tuned to produce that to suit the CVT, not that the CVT is the reason for it. Could it also be how they modified the cvtcs to produce that kind of torque?

[nametakennow]

SAE requires that power and torque be measured at the wheels now. The gearing of the manual cars is probably the factor here outside of the differences in engine design. However, most of the difference likely has to do with the difference in compression, which I'm assuming is true.

Note that the CVT vehicles will basically never see 5200rpm, so the engine tuning had to be different - you wouldn't want to sit at 5200 as your "optimal" rpm.

[gotak]

It does goes up to 5k and more if you stuff your foot down.

The tuning is just to suit the CVT's tendencies to go to top gear ratio at all times. Having that torque peak low means they can stay at higher ratios and get better fuel economy numbers while keeping the car relatively responsive.