S2000 Under The Hood S2000 Technical and Mechanical discussions.

VTEC Engagement

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Old Jun 3, 2005 | 12:07 PM
  #1  
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Default VTEC Engagement

Me and a buddy of mine are interested in getting the 4.77 final drive gear for our cars but something that is holding both of us back is the fact that you'd be cruising at very high rpm @ freeway speeds. Roughly around 90-95mph we'd be crusing above 6000 rpm and that would be in the "vtec" zone.

My question is, even if you are cruising at 6000rpm or above, does that mean vtec is engaged? Or are there a few conditions that need to be met for it to engage like:

1) Throttle Position
2) RPM
3) Oil Pressure

Thanks


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Old Jun 3, 2005 | 02:13 PM
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From: LittlecountrynamedBelgium
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6000 rpm = VTEC is engaged, no mather the trottle position! It's a mechanical action once you pass the right rpm's. Of course, if you are low on oil, VTEC could not engage since it works on the engine oil. Same story when the engine temp is still cold you have the rev limiter that won't allow you to go into VTEC...
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Old Jun 3, 2005 | 02:23 PM
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And I actually believe if the car is not moving VTEC won't engage the hi cam. I think it does make sure there is vehicle speed/movement.
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Old Jun 3, 2005 | 02:47 PM
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I've gone over 6K in my car without feeling/hearing the VTEC kick in. I'm just not flooring the pedal. Does that mean the VTEC has still initiated but waiting for me to get into WOT?
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Old Jun 3, 2005 | 03:12 PM
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Does anyone know for sure? Thanks for the input guys.
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Old Jun 3, 2005 | 03:33 PM
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Originally Posted by arcadence,Jun 3 2005, 02:47 PM
I've gone over 6K in my car without feeling/hearing the VTEC kick in. I'm just not flooring the pedal. Does that mean the VTEC has still initiated but waiting for me to get into WOT?
Yes.
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Old Jun 3, 2005 | 09:41 PM
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From: LittlecountrynamedBelgium
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Once you pass the 6k rpm your S2000 will allways be in VTEC (high cam profile) no mather what, exept for the low on oil and cold rev limiter. But because you don't hit the throttle that hard you will not notice it that much. If you floor the throttle the kick will be there, i'm shure of it This is the difference with for example the vanos from BM*** or the variocam from Porsch***, those systems are variable and will continuously change the hight of the cams based on rpm's, throttle position and some other factors. But you don't get the VTEC kick that much since it is an on/off think in our S'ses...
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Old Jun 3, 2005 | 11:09 PM
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Sorry Lionheart but you are wrong. VTEC is engaged by oil pressure but the solenoid that triggers it is triggered by a single line from the ECU. Devices like the V-AFC and E-manage use this line to change engage VTEC at a user setable RPM.

The stock ECU uses a number of parameters to decide whether or not to engage VTEC such as RPM, Engine Coolant Temperature and Throttle Position. Someone like SlowS2k can probably give you more specifics but those are the sorts of parameters it uses.
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Old Jun 4, 2005 | 01:33 AM
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From: LittlecountrynamedBelgium
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Am I that wrong I've been S2000'ing the internet (especially the tech specs) for months and months now, and I have never heard of the fact that VTEC would not always engage at the factory set rpm exept of course for the known VTEC disablers such as not warm enough water coolant, low on oil, oil pressure problems...

But I guess you guys over here will know it for sure, so I presume you are correct It still is hard to believe for me that the standard cam's would take the engine above 6k. So what you're saying is that our VTEC system is intelligent and decides whether or not to send oil pressure to the VTEC engagement pin based on throttle position once the coolant temp is high enough and the engine reached 6k? So if I took it very slowly, would I be able to use the standard cam to 9k? This is very new for me, I'm in shock
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Old Jun 4, 2005 | 06:08 AM
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The VTEC engaugement point can be varied by the PCM based on engine load. Most of the time, it's "on" above 6k rpm.

The coolant temp must be above 3 bars (on a 00-03) or approx 150 degrees.

The oil pressure required to maintain VTEC operation is 57psi.
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