How does VTEC work??
09-17-2003, 12:47 PM
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How does VTEC work??
HI I just purchased my 1st non american car! I just got a 2000 TL with 35,000 miles on it! I have a couple of questions! 1st how does the VTEC work, What RPM does it usually kick in, and Can you hear it as it engaging? This may seem like silly questions but I'm new to imports and I would like to know! Anyfeedback would be most appreciated!
09-17-2003, 12:53 PM
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Welcome. The VTEC junkies will tell you that VTEC doesn't kick it. It has two profiles. Low and high (or something like that). In the TL it switches to high around 4,500RPM. In the TL you really don't feell a sudden pull rather than just a nice smooth torque curve that allows the engine to keep pulling nicely to redline. You can hear it switch modes. The engine will sound different. Run the car up to around 4500rpm in 2nd or 3rd and you will hear what I mean.
One word of advice. The search is your friend on this board.
One word of advice. The search is your friend on this board.
09-17-2003, 01:34 PM
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Actually VTEC is capitalized since it stands for "Variable valve control with lift, electronic control". Yeah, its a convoluted name that the engineers changed to VTEC.
Basically it allows for the valve timing to change AND the lift duration of the valves.
This allows the engine to breathe better, since engines have different breathing requirements at low rpms and high rpms.
Basically it allows for the valve timing to change AND the lift duration of the valves.
This allows the engine to breathe better, since engines have different breathing requirements at low rpms and high rpms.
09-17-2003, 01:46 PM
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Originally posted by r10apple
First of all, some techie will flame you for capitalizing vtec!!!
Wow, I'd answer the rest but I'm about spent.
First of all, some techie will flame you for capitalizing vtec!!!
Wow, I'd answer the rest but I'm about spent.
Happy reading: http://www.acura.com/models/types_te...ech&page=vtec1
09-17-2003, 03:06 PM
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On the CL/TL there are three cam lobes per intake valve set. The rocker arms which are attached to the valves follow the two outside lobes which have a lower lift and duration spec. They are also different from one another giving a staged effect to the intake charge and providing better swirl. These operate under low RPM levels (the Type-S change over point is 4800 RPM).
There is also another rocker arm which is following the center lobe which has a higher lift and duration. But this rocker is not attached to anything else and idles on the rocker pivot shaft.
At 4800 RPM an oil control solenoid opens filling the rocker arm pivot shaft. This engages a small pistion which locks all three rockers together. Since the middle cam lobe has a higher lift and duration, all three rocker are now following this profile. This now changes the lift and duration of the valves.
There is also another rocker arm which is following the center lobe which has a higher lift and duration. But this rocker is not attached to anything else and idles on the rocker pivot shaft.
At 4800 RPM an oil control solenoid opens filling the rocker arm pivot shaft. This engages a small pistion which locks all three rockers together. Since the middle cam lobe has a higher lift and duration, all three rocker are now following this profile. This now changes the lift and duration of the valves.
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09-20-2003, 05:37 PM
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I think the sound we hear at around 4500 rpms in the intake manifold swithing to the short runners. i thought vtec switched cam profiles a little higher. could be wrong though.
09-20-2003, 05:53 PM
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http://auto.howstuffworks.com/question229.htm
this will help
this will help
09-20-2003, 09:33 PM
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Originally posted by TimN88
I think the sound we hear at around 4500 rpms in the intake manifold swithing to the short runners. i thought vtec switched cam profiles a little higher. could be wrong though.
I think the sound we hear at around 4500 rpms in the intake manifold swithing to the short runners. i thought vtec switched cam profiles a little higher. could be wrong though.
Also, the dual stage intake manifold is not a variable runner length system so there is no switching to shorter runners. The Type-S uses a variable volume system where at low speeds the effective volume available to each bank of runners is half of what it is after the butterfly valve opens at 3800 revs.
09-21-2003, 11:14 AM
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Originally posted by njtls
wow..so much **** moves..how would we know if the intkae runners stoped wroking?
wow..so much **** moves..how would we know if the intkae runners stoped wroking?
09-21-2003, 11:34 AM
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Originally posted by TimN88
the sound i was refering to was the different intake note when the system changes over.
the sound i was refering to was the different intake note when the system changes over.
09-21-2003, 12:08 PM
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09-21-2003, 12:28 PM
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Originally posted by NYDesi80
Its honda's cheap fix to not having to make a turbo!
J/K
Its honda's cheap fix to not having to make a turbo!
J/K
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