GenVibe - Community for Pontiac Vibe Enthusiasts

Hey guys, long story short... I used to own a 2001 Celica GTS with the same 2zz engine and now I'm a recent owner of a 2005 Vibe GT with the same motor. When I accelerate, at exactly 4000 RPM I'm noticing a deeper pitch in my intake and a bit quicker acceleration. Then it's the usual lift at 6700 rpm to 8000. I was wondering if anyone could shed some light on what's happening with this motor at 4000 rpm as I've never noticed this on my 2001 Celica gts. Has the 2zz changed since then?

Thanks in advance!

Info I found on wiki:
Toyota commissioned Yamaha to design the 2ZZ-GE, based on Toyota's ZZ block, for high-RPM operation and producing a power peak near the top of the RPM range. The high-output cam profile is not activated until approximately 6,200 rpm, (lift set-points are between 6,000-6,700 rpm depending on the vehicle) and will not engage until the engine has reached at least 60° celsius (140° fahrenheit.) The Toyota PCM electronically limits RPM to about 8200 RPM via fuel and/or spark cut. The "lift" engagement and the engine redline vary by application.

From what I understand the Vibe/Matrix 2zz will put down more HP than the Celica 2zz. Perhaps the tuning (timing) is more aggressive at 4K. Are you at WOT when you hit 4K?

Salsa Guy wrote:From what I understand the Vibe/Matrix 2zz will put down more HP than the Celica 2zz. Perhaps the tuning (timing) is more aggressive at 4K. Are you at WOT when you hit 4K?

When I'm WOT I hardly notice it, but when I'm midway on the pedal, I hear the difference...like it's ready to push harder.

Maybe it's the valve overlap from the VVT kicking in, rather than the aggressive cam profiles from lift being used. Do you get a second boost at 6400?

I can definitely feel when VVT kicks in, and it does get louder and starts pulling when the parameters for engagement are meant. As I don't have a heads-up display, I can't really safely watch my RPMs when I gun it, so I can't tell you anything beyond that it's at at least 4k+ RPMs with firm pressure on the gas pedal. From what I've read, VVT-i engages according to conditions and thus operates under a variety of situations depending on what the ECU feels is appropriate for its current status and what it thinks you are asking it to do.

I don't know what lift feels like, but descriptions from other people suggest to me that it feels like VVT-i valve overlap but with a far more savage pull.

VVT-i can vary valve opening and closing times independently, so there are all kinds of changes going on with RPM as well as throttle position and engine temperature.
The 1zz in my '06 Matrix makes a distinct exhaust growl on startup when it's below ~50F. I'm sure it has to do with valve timing.

Hmm...I guess that explains a lot. Thank you guys!