When exactly does V-tec kick in on the civic si 03?

I rode in my friends new accord and at 3.5k you can tell it kicks in hard, however I Can't tell at all on the 03 civic..

 

it hits at 2200 rpm, yeah your probably wondering why, it is because vtec on the si is different from say vtec in the rsx type s or a b series motor. on the si below 2200 rpm the engine only runs on 12 valves (only one intake valve opens), it does this to give you better gas mileage and less emissions, sadly vtec on the si is not designed for performance. so you will probably never hear vtec hit.

 

hes right, the K20A2 and K20A are the ones with vtec on both cams.

 

thats why u need to swap out the a3 head for a a2 head and get real vtec

 

My understanding is that it is a dual stage vtec. Kicks "softly" at 3200 then really hits at 5000 to 5200 depending on load. I just installed a AEM CAI and you really cant hear it until about 51 -5200. I had also heard "the 12 valve theory" but have not been able to find any proof. Not that I've looked to hard!!! I may be completly wrong, I'm a F***ing bong salesman not a tech.

 

heres all the proof you will ever need strait for honda http://asia.vtec.net/article/k20a/index.html
Or this one explains it extremely wellhttp://www.superhonda.com/foru...05867

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elephantpastry &raquo;</TD></TR><TR><TD CLASS="quote">http://www.superhonda.com/foru...05867</TD></TR></TABLE>

They'll never learn if you make them read for themselves. LOL...

It does explain, however, why the K motor in the EP3 Si feels like it has so much torque off the line and why it's so pleasant in everyday driving compared to that "other" Si 160 HP motor, the ol'e B16 in the earlier Si.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">The K20A3 engine used in the Acura RSX base has a slightly different intake manifold design from the K20A3 engine used in the Civic Si. The RSX engine uses a dual-stage manifold, similar in concept to the manifold of the B18C1 in the old Integra GSR. It uses long intake runners at low-RPM to retain low end power, and switches at 4700RPM to a set of shorter intake runners to enhance high-end torque. </TD></TR></TABLE>

And this answers the RSX-Base/Premium vs Si arguments we're always hearing.

That was really very informative.

Thanks very much for posting it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Towlieee &raquo;</TD></TR><TR><TD CLASS="quote">When exactly does V-tec kick in on the civic si 03?

I rode in my friends new accord and at 3.5k you can tell it kicks in hard, however I Can't tell at all on the 03 civic..</TD></TR></TABLE>

It's vtec not v-tec, and it does'nt kick in its suppose to be a smooth transition.

 

it makes the car have more drivability and fuel savings. there is no real transition

 

all true. i also believe it kicks in at around 3200 and finally around 4500 and 5k. emissions, emissions, emissions...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kal &raquo;</TD></TR><TR><TD CLASS="quote">it makes the car have more drivability and fuel savings. there is no real transition </TD></TR></TABLE>

Small to big Cam thats what I call a transition.

 

Thanx, that is the proof!! Great Post

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by C-Zero &raquo;</TD></TR><TR><TD CLASS="quote">

Small to big Cam thats what I call a transition.</TD></TR></TABLE>
hey why don't you read what i posted earlier and stop being so cocky, Cause small to big cam is not really happening in the new Si.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elephantpastry &raquo;</TD></TR><TR><TD CLASS="quote">
hey why don't you read what i posted earlier and stop being so cocky, Cause small to big cam is not really happening in the new Si. </TD></TR></TABLE>

I not talking about the new SI I'm talking about true VTEC.

 

Will soemone answer this for me?

Does vtec mean variable timed electronic control, or is it just a engine code? someones trying to tell me its a code for the way the engine works..

Also is the 03 civic SI odb 2 or odb2.5?.. someone tellin us its 2.5 but the owner says 2.0

 

I can hear my vtec hit. But only when the motor and exhaust are cold. The exhaust helps to hear it, but only a very slight change in sound. Oh well, thats what swaps and turbos are for...to make up for what your car doesnt have.

 

speaking of exhausts, any EP3 owners in need of one? I have a great buy posted in the classified section. It is a group buy, go check it out at https://honda-tech.com/zerothread?id=834121