What Inputs Trigger VTEC On and Off
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From: Dry Branch
Originally Posted by pushinlsteg,May 7 2006, 07:25 PM
I have a RED LED light wired straight into the ECU harness to light up with vtec engagement. at a dead stop, the light comes on if I'm at full throttle past 6000 rpm.
normal?
normal?
I not sure that it is "normal" to rev at full throttle past 6000 rpm when at a dead stop, but your car is behaving normally. 
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From: Dry Branch
Originally Posted by scottrunsxc,May 7 2006, 07:38 PM
Like I said, I may be wrong. I get my information from personal stupidity and nothing else. I was trying not to go into it b/c I know I'll get flamed for S2000 abuse. Anyway, I've gotten myself into a bind before the car was fully warmed up. It was either get in a wreck or get out of the way, I elected to get out of the way.
Here's what you do, go crank up the car, find a place with no traffic, make a u-turn slowly in 1st gear before fully warming up the car. Halfway through the turn floor the gas pedal, hang the rearend out, take the car above 6000rpms and see if you hit the rev limiter. In my experience, you will not hit the limiter. On this occasion I was around 7500rpms. This either means that traction is a limiting factor in VTEC changeover, or that VTEC can change over without reaching operating temperature. Since it is common knowledge on this site that VTEC will not operate below "3 bars" (in an AP1) I can only assume that traction is a limiting factor in VTEC changeover.
Sorry if I was relaying incorrect information. Just seemed to be a logical assumption to me. If someone can explain this to me, I'm all ears.
Here's what you do, go crank up the car, find a place with no traffic, make a u-turn slowly in 1st gear before fully warming up the car. Halfway through the turn floor the gas pedal, hang the rearend out, take the car above 6000rpms and see if you hit the rev limiter. In my experience, you will not hit the limiter. On this occasion I was around 7500rpms. This either means that traction is a limiting factor in VTEC changeover, or that VTEC can change over without reaching operating temperature. Since it is common knowledge on this site that VTEC will not operate below "3 bars" (in an AP1) I can only assume that traction is a limiting factor in VTEC changeover.
Sorry if I was relaying incorrect information. Just seemed to be a logical assumption to me. If someone can explain this to me, I'm all ears.
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Originally Posted by Tugz_S2K,May 7 2006, 07:32 AM
^ Its more then just that
VTEC change over occurs under the following conditions
-The engine must reach its target RPM value - in the S2000, 6k rpm
-Their must be sufficient oil pressure, which is determined by the VTEC Solenoid valve
-Throttle position must be at a certain % and higher
-ECU must pick up a speed signal from the transmission
-Coolant must reach a temperature level or higher.
VTEC change over occurs under the following conditions
-The engine must reach its target RPM value - in the S2000, 6k rpm
-Their must be sufficient oil pressure, which is determined by the VTEC Solenoid valve
-Throttle position must be at a certain % and higher
-ECU must pick up a speed signal from the transmission
-Coolant must reach a temperature level or higher.
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From: Dry Branch
-The engine must reach its target RPM value - in the S2000, 6k rpm
-Their must be sufficient oil pressure, which is determined by the VTEC Solenoid valve
-Throttle position must be at a certain % and higher
-ECU must pick up a speed signal from the transmission
-Coolant must reach a temperature level or higher.
In general, and specifically, those are the ONLY factors that affect VTEC engagement. I think he was just trying to answer your question.
-Their must be sufficient oil pressure, which is determined by the VTEC Solenoid valve
-Throttle position must be at a certain % and higher
-ECU must pick up a speed signal from the transmission
-Coolant must reach a temperature level or higher.
In general, and specifically, those are the ONLY factors that affect VTEC engagement. I think he was just trying to answer your question.
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Thanks for the responses.
What is the required throttle position? Does it change at different engine speeds? For example, 6000 at WOT, 6500 at 75%, 7000 @ less than 75%?
What is the logic to return to the primary lobes? I understand it is a lower speed. Is there also a delay?
Are you sure it is 6k? Is that the same for both the F20 and F22? I thought it was 5600.
And, how do you adjust it? Do you need a piggyback or replacement ECU (like Supra modifications) or just tuning software (like a Chevy LS1)?
Thanks,
David
What is the required throttle position? Does it change at different engine speeds? For example, 6000 at WOT, 6500 at 75%, 7000 @ less than 75%?
What is the logic to return to the primary lobes? I understand it is a lower speed. Is there also a delay?
Are you sure it is 6k? Is that the same for both the F20 and F22? I thought it was 5600.
And, how do you adjust it? Do you need a piggyback or replacement ECU (like Supra modifications) or just tuning software (like a Chevy LS1)?
Thanks,
David
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From: Milwaukee Area
Originally Posted by pushinlsteg,May 7 2006, 06:25 PM
I have a RED LED light wired straight into the ECU harness to light up with vtec engagement. at a dead stop, the light comes on if I'm at full throttle past 6000 rpm.
normal?
normal?
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From: Milwaukee Area
Originally Posted by Project22a,May 7 2006, 11:24 PM
were you going faster than 13mph while you were spinning?