So our cars have this new technology, but I'm curious if anyone knows when it kicks in? (at what rpm?)

Like the V-tecs and everyone else who has this technology, you can usually tell exactly when the "switch" happens.

All I notice is a little bit of a lag right at 3k rpms. Does anyone else feel this if you're slowly accelerating? I feel a little stutter right at 3k that I only notice if I'm at about 1/4 throttle or less. If that's not the valve "switch", then what could it be?....Should I bring it in?

Thanks!

 

Vtec is an older technology that has two different cam timing options and one or the other is selected. Consequently it "switches" A or B. On this engine it is not a A or B scenario. The cam adjustments are dynamically controlled...it is a gradual change instead, so it's impossible to say exactly when it goes "on or off".

 

That's understandable. My question then remains....does anybody else notice a hesitation at 3k? It seems to have become more noticable over time. I just crossed 16k miles on my 06. I don't want it to become a bigger problem.

 

VCT on your mustang is ONLY for EGR. It provides no increase in engine output. In other words, your car will dyno the same with the VCT solenoids unplugged than it will with them plugged in. The cams default position is full advance. On light accel and cruise, (when EGR would normally work) the cam retards a bit and allows for enough valve overlap to have the exhaust valve open slightly on the intake stroke.........end result - EGR without putting on a valve, an EVR, and a flow sensor.

 

No hesitation at 3k on my car.

 

Thanks 07GT. Any others? I'd love to hear from as many people as possible. Thanks

 

I see you have a tune, you may want to try reflashing the computer, even with a tune, the computer will adapt and change the ramp rate, more than likely this is your issue.

 

The only simalarity between VCT and VTEC is that they both start with a V.

Ford's VCT can only vary the timing of the valve opening. (Advance/Retard) and is used to replace the old EGR system.

VTEC varies duration, timing and lift by switching between two different sets of cam lobes.

 

Good explanation LBJay. I had this hesitation thing before I ever did a tune.

 

If I've been in slow traffic, like road construction, I'll get a little hesitation going from 2nd to 3rd at 1/2
throttle when the road clears. I'm hoping a tune will help.
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