Thread: question about VVL of SR20VET

Is VVL more for environmental conformance or more for additional power?
On x-trail in stock VVL starts from 5000 rpm, I’ve readjust it and now it starts from 2500 rpm

More power. Why the hell would you put the crossover point so low?

Its for power, but "specifically" its to improve the low end response (idle and driveability down low) while maintaining a rising power curve in the top end. Giving you the best of both worlds.

Engaging at 2,500rpm is likely 3 things.

1. Pointless
2. dangerous for the motor if the tune isn't checked or adjusted.
3. actually making the car slower.

could you please give me more details or explanations why it's pointless and making car slower?

You have not modified the fuel or timing maps which are set for the 5000rpm switch.

i agree, without being on a dyno or able to tell if you are actually make better power or improving the powerband, i would keep the crossover for what it is set at. you might improve the bottom end powerand and hurt top end.

if you are looking to improve bottom end or mid performance you should do some modifications that will improve those parts of the powerbnd instead of relying on adjusting the cross over to do so.

why you think i've not modified it? i modofied all maps actually, as now motor is managing not by original ECU but by Autronic

please advice me how can i improve bottom end or mid performance?

Have you had the car on the dyno. Thats where I would play with switch point so you can actually see if your hurting or improving performance. I have my ve-t setup to switch at 4000rpm for both cams.

what other mods have you done to your x-trail?