vtec? k20a

[Jharobikesr2]

I recently swapped the k20a into my car and i have noticed that vtec seems to be not working... I no longer feel it or hear it.

I did just recently have it tuned, they wouldn't turn vtec off would they?

[talonXracer]

Properly tuned you should not feel or hear a sudden slam bang VTEC, it should be seamless in it's onset, a sudden slam means an improper tune, ie lower whp! You should still hear the xover, just that it is not as an intense pop sound, but just as loud And the power should be just a continuous rush with no real sudden surges.

The factory bang is a selling gimmick while reducing the power to satisfy the legal dept.

[lbk02si]

Properly tuned you should not feel or hear a sudden slam bang VTEC, it should be seamless in it's onset, a sudden slam means an improper tune, ie lower whp! You should still hear the xover, just that it is not as an intense pop sound, but just as loud And the power should be just a continuous rush with no real sudden surges.

The factory bang is a selling gimmick while reducing the power to satisfy the legal dept.

Interesting, never knew that.

[Draw7Seven]

Troof. Vtec in a properly tuned setup is basically just the adjustment that allows the power curve to continue at higher RPMs, you shouldn't hear a mad crazy JDM tight crossover.

[SandBagger]

The I-vtec helps in this matter

[Jharobikesr2]

Thank you for the help, I never knew that. I only said something cause when i first got the motor vtec was very noticeable after my tune.. not so much.

thanks guys

[talonXracer]

The I-vtec helps in this matter

???huh???

You tune the x-over the same way regardless of whether the VTEC engine has VTC or not.

[IBx1]

By K20a, do you mean the a2 or a3? Very different engines, and worlds-different vtec.

[SandBagger]

???huh???

You tune the x-over the same way regardless of whether the VTEC engine has VTC or not.

Refering to the way a F20 feels. Yeah a tune should provide no Vtec kick, the added mid-range Tq make it easier to tune the transition on lobes. My old ep3 was in VTec all the time....lol

[RedSiBaron]

By K20a, do you mean the a2 or a3? Very different engines, and worlds-different vtec.

He means k20a, as in the type r motor from japan

[TXEP3]

Properly tuned you should not feel or hear a sudden slam bang VTEC, it should be seamless in it's onset, a sudden slam means an improper tune, ie lower whp! You should still hear the xover, just that it is not as an intense pop sound, but just as loud And the power should be just a continuous rush with no real sudden surges.

The factory bang is a selling gimmick while reducing the power to satisfy the legal dept.

My VTEC pops... of course I have stage3 cams and ITBs... still though now that you mention it, I wonder if it should be smoother.

[RedSiBaron]

My VTEC pops... of course I have stage3 cams and ITBs... still though now that you mention it, I wonder if it should be smoother.

Do you run a collector plenum on your itbs?

[TXEP3]

Do you run a collector plenum on your itbs?
Nope. I have individual foam filters for each bell.

(also you could have stage3 cams and ITBs if the price is right =P)

[RedSiBaron]

Nope. I have individual foam filters for each bell.

(also you could have stage3 cams and ITBs if the price is right =P)

Can you post a pic...im glad you have filtration on them...not trying to be a jerk, but you are probably not utilizing the advantage of the itbs...kinda the point is the velocity stacks and to flow air over them correctly (smoothly without turbulance), thus accelerating the air into them, you need to run a collector plenum...just sayin

[TXEP3]

http://img577.imageshack.us/img577/323/0805001230.th.jpg (http://img577.imageshack.us/i/0805001230.jpg/)

[JIYAKKU]

The factory bang is a selling gimmick while reducing the power to satisfy the legal dept.

Yup. Check out the stock 06 Civic Si dyno graph in red below (The black graph was my old A3 with Stage 2 Camshafts so it is irrelevant in this case). I circled the dip in power right before it makes the transition:

http://i472.photobucket.com/albums/rr86/jiyakku/VTAKStockDip.jpg

[SandBagger]

when racing a loss in the midrange could mean the loss. the greatest thing that the K20 and K24 have is midrange. Next is the ability to rev past there stock redline and they do not break easily.