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!

 

First of all, some techie will flame you for capitalizing vtec!!!

Wow, I'd answer the rest but I'm about spent.

 

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.

 

Hey Thanks for the reply! I was just looking for an explenation on how it works! Thanks!!

 

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.

 

Some people may also flame him for not using the search button, or not visiting Acura's website... but we won't get into that

Happy reading: http://www.acura.com/models/types_te...ech&page=vtec1

 

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.

 

Its honda's cheap fix to not having to make a turbo! J/K

 

Duh...

 

cool

 

But it sure sounds like a turbo when vtec kicks in.:p

 

It SURE DOES !

 

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.

 

http://auto.howstuffworks.com/question229.htm
this will help

 

The IMRC opens at 3800 and the VTEC change over is at 4800.

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.

 

wow..so much **** moves..how would we know if the intkae runners stoped wroking?

 

I didnnt know it was a variable volume system. the sound i was refering to was the different intake note when the system changes over.

 

Actualy it should be "how would we known if the IMRC (butterfly) valve stopped working"; you would seriously notice a loss of power after 4k revs. You loose about 15 - 20 lb/ft through most of the rev band after 4k revs.

 

That is the VTEC change over you hear; should occur around 4800 revs for the Type-S. That sound is wonderful!!!

 

http://www.leecao.com/honda/vtec/index.html

is your friend

 

It's just a different way to do the same thing. Actually I prefer VTEC over turbo. My last car was a Volvo 850-turbo and I liked everything about it except the "turbo lag". The car was maybe a little quicker to 60mph than my TL but in a non-refined sort of way. On hard acceleration it was one-one thousand, two-one thousand then OMG! The Acura system is much smoother.