[dot]

Vtec indicator installed.

First a little history of my misconception.

I used to think that vtec is a point where the cam geometry changes. It occurs when a hydraulic unit connects two different lobes of the cam shaft when is triggered by a solenoid. There is lot more to this, I am not trying to write a exposition on vtec, it has been very well documented on the net. Simply put, this results in the engine producing more power when vtec is activated. The vtec point is usually around 5000 RPM. Perhaps all this is true for older Honda vtec engines, but not so for the i-vtec or our R18A. This great piece of information never dawned on me till recently when I saw it in action, live. More on this later.

Now back to vtec indicator installation.

So my naive mind was fixated on a vtec point discovery when the engine is supposed to generate more power. I wanted to know when this occurs. So searched the net till I found two solutions. Both involved attaching a LED that can tell when vtec is activated or not.

1. Take the vtec pin from the ECU and attach a LED to that line.
2. Find the vtec solenoid, attach the LED to the electrical line connecting the ECU to the solenoid.

For R18A, finding the ECU pinout information turned out to be a impossible task. Found a few diagrams on the net, but was not sure if it was for the 2.0L Si or 1.8L R18A.

Finally found a link where a good hearted soul found the way to tap the solenoid line. I had to simply replicate his efforts. Here is the link

i-vtec solenoid wiring help - 8th Generation Honda Civic Forum

Now for some pictures.


The solenoid behind the valve cover. You can see the harness with two wires, the black wire with white stripe is the positive line. The line was used to take the leads.




Initially we took the lead through the door and connected it to a multimeter to check if indeed we are getting on or off type signals. A TD was undertaken. There we found out that the line gets a signal of 12-13V during low load conditions. With aggressive driving, the voltage becomes zero.





The dummy switch was used to house the LED. In these pictures the dummy switch is being prepared by burning a hole through the center and inserting the LED holder. The LED had a 1K resistor attached to it.



Final pictures from the engine bay. The solenoid harness looks like this now.


The wire was taken to through the firewall using an existing port which had a rubber cap.


The wire under the driver's footwell.


LED wire and solenoid's parallel connection being mated.


Final look of the dashboard.


A picture of the LED glowing during driving.



Driving impressions

The LED glows when vtec is activated. Found out that vtec comes on only during low load conditions. That is, irrespective of which gear is engaged, vtec is activated if only,

1. RPM is over 1500 and less than about 3000.
2. Very light throttle position.

So if you redline from idle, vtec is never activated. Thats why, if you rip the Civic, you never seem to trace that old vtec kick. Because there wasn't any kick in the first place. The R18A is designed to have vtec as a fuel saver, not power booster. The R18A is always in high power mode, when vtec is engaged it goes to low power/better economy mode. This is very different from other Honda engines, where the base level of the engine is in low power mode, after vtec it goes to high power mode. The same was always written on the "temple of vtec" article on R188A (the link has been posted a few times on the forum by several folks) and wikipedia. Never realized it till now.

So the indicator serves as a economy indicator. I am planning to test this on long term basis, specially during highway driving and check FE results with Vtec on or off.




P.S.: I also need to thank mdsaab for introducing me to this person who is pretty good with electricals and electronics. And Laluks and Sushrutha for encouragement.

[Akshay1234]

Wow I didn't believe your theory at first. But then I did a bit of research and turns out its true. So in the r18 when the Vtec is on the car is on FE mode.

Quite odd considering Honda has reversed the role of vtec.

[mdsaab]

Hey Dot.
So you finally did get it installed.
Fantastic and what a discovery that the I-vtec on the r18a works in a totally different manner than what we expect it too. Looking forward to taking a test drive of Scorpo soon.

[dot]

Originally Posted by akshay1234

Wow I didn't believe your theory at first.

Quite odd considering Honda has reversed the role of vtec.

Thanks, I would not have believed it myself. The good thing is that the engine is on high power mode from the word go. So we dont have to wait for the vtec to give any additional boost.

Originally Posted by mdsaab

Fantastic and what a discovery that the I-vtec on the r18a works in a totally different manner than what we expect it too. Looking forward to taking a test drive of Scorpo soon.

Thanks. Yes, I will sit on the back seat this time; only to film the LED and the speedo + tacho in the same frame.

[dot]

This has been a good weekend. First the installation of the vtec indicator (see above), next the understanding of how i-vtec works in our Civics. Now we could connect Jealousdiamond's ELM 327 bluetooth OBD device to the car and the phone and check out a few cool features.

We had downloaded a Symbian based software OBDscope on my X6. This time the connection was established and we could monitor some nice stuff like power, torque, throttle position apart for instantaneous FE, RPM, speed, GPS speed. The software has a few limitations like it only shows one gauge at a time. However it also picks up DTS codes and performs diagnostics. The device could connect to Jealousdiamond's Safari and Indica too. Now I need to procure a ELM device.

[arvi86]

That's brilliant dot. Thanks for the info, it acted as an eye-opener for me. Not sure about others, but I was thinking that the V-Tec works in exactly the opposite way to what you posted. Do let us know the difference in mileage in the V-Tec On and Off modes.

[spadix]

Originally Posted by arvi86

but I was thinking that the V-Tec works in exactly the opposite way to what you posted.

That was VTEC (then). This is iVTEC (now).

If I remember correctly, iVTEC is not limited to the implementation we find on the R18A. Subsequent Honda iVTEC units could have totally different implementations of VTEC. At least that's what I could make out of that Temple of VTEC Asia article and a couple of other related articles I read online.

So you can think of iVTEC as not just one technology or implementation but a basket of multiple different things Honda does. It's become a "brand name" in the true sense now.

Regards,
spadix

[GTO]

Thanks for sharing, Dot! I've copied your Vtec indicator posts to a new thread.

[Vid6639]

It'll be interesting to see how the i-vtec works on the ANHC. The power delivery is a little different in that one.

[spadix]

Originally Posted by vid6639

It'll be interesting to see how the i-vtec works on the ANHC. The power delivery is a little different in that one.

Temple of VTEC Asia might have an article on it.

@dot: Forgot to mention this earlier, but *good* work! It's always nice to see in practice what one has learnt from theory. Please let us know about your ELM installation as well when you get around to it. That's one thing I would really love to have in my BQ.

By the way, what's that switch next to the headlight level adjuster? Is that the fog lamps switch? It's coloured differently. Has Scorponok got after-market fog lamps?

Regards,
spadix

[Guna]

Does this mean the V-tech on i Vtec doesn't provide power boost? What I have observed in in my ANHC is, if you slam the accelerator, there is a point at which you feel the power surge and even the engine tone changes. I always thought this to be V-tech coming in to action.

[pranavt]

The R18s iVtec is a little different. It's a pity we got the R18 with the Civic, Honda could have done some good by bringing in a K series engine with the Civic. Nonetheless, here is how it works on Indian Civics.

Technical Overview of Honda's new R18 i-VTEC Implementation

[dot]

Originally Posted by Guna

Does this mean the V-tech on i Vtec doesn't provide power boost? What I have observed in in my ANHC is, if you slam the accelerator, there is a point at which you feel the power surge and even the engine tone changes. I always thought this to be V-tech coming in to action.

I think ANHC's engine is derived from L-series Honda engines which is a different breed from Civic's R18A. If that is true, then the following article explains ANHC's vtec operation. ANHC in that case, has "normal" vtec operation.

Honda L-Series SOHC i-VTEC Engines for the new GD Honda Fit/Jazz

Someone please confirm if ANHC's engine is L series Vtec.

[vasoo]

Originally Posted by dot

I think ANHC's engine is derived from L-series Honda engines which is a different breed from Civic's R18A. If that is true, then the following article explains ANHC's vtec operation. ANHC in that case, has "normal" vtec operation.

Honda L-Series SOHC i-VTEC Engines for the new GD Honda Fit/Jazz

Someone please confirm if ANHC's engine is L series Vtec.

You are right. ANHC comes with L15A7 engine. And it is an iVtec.

[sushrutha]

Super...
WOW Never thought this was so cool.
I'm gonna install this very shortly ;-)
When I spoke with RD Karthik, he told me one has to build a Circuit while connecting from the ECU pins for tapping the VTEC indicator.

You have got this done as a Child's play.
Wish I had a button to thank you 100 times ;-)

Originally Posted by dot

1. RPM is over 1500 and less than about 3000.
2. Very light throttle position.

So if you redline from idle, vtec is never activated. Thats why, if you rip the Civic, you never seem to trace that old vtec kick. Because there wasn't any kick in the first place. The R18A is designed to have vtec as a fuel saver, not power booster. The R18A is always in high power mode, when vtec is engaged it goes to low power/better economy mode.
So the indicator serves as a economy indicator.

Thanks for this excellent piece of Information on R18A I-VTECinformation.
I always thought in a Opposite way.

Now I know as why I was suddenly getting Low F.E.

This LED glow is perfectly working like the ECONOMY/POWER mode indicator, which the First generation TVS Victor had(I believe they still have a pending patent on it )

Originally Posted by spadix

By the way, what's that switch next to the headlight level adjuster? Is that the fog lamps switch? It's coloured differently. Has Scorponok got after-market fog lamps?

He has OEM Fog lamps in his SCORP, so that should be the switch for the Fogs.