I have a 1997 Civic HX (d16y5). I installed a VTEC switch so I could turn on VTEC whenever I wanted. What I did was tied into the cigarette lighter power wire (12V) and ran it to the VTEC wire on the ECU. Most of you are probably familiar with VTEC-E, but in case you aren't, here's how it works. When it is not in VTEC mode, each cylinder only operates on 3 valves (1 intake, 2 exhaust), then when VTEC kicks in, it runs on 4 valves (2 intake, 2 exhaust) per cylinder. So I figured my car would be a little faster if I could engage the VTEC all the time. But it is actually slower when VTEC is engaged at low RPMs. Can anyone tell me why this is so?

 

Ok, in order to understand why this happens you first must understand the operation and benefits of VTEC. VTEC engages at a set RPM in order to optimize fuel efficiency and power. VTEC was not invented to make your car faster. The fuel effiency is the big kicker. So the reason your car is "slower" with VTEC engaged in the low RPM range is because your air/fuel ratio is all fucked up. VTEC switches = bad idea IMO. Your running too lean in the low RPM range. In the ECU some extra fuel is provided from VTEC engagement to redline. Pull the switch and the motor and go from there. Invest in a HonData s200. I could go more in depth in to the operation of VTEC but I wouldn't want to scare the simple minded newbs.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondaFanatic708 &raquo;</TD></TR><TR><TD CLASS="quote">Ok, in order to understand why this happens you first must understand the operation and benefits of VTEC. VTEC engages at a set RPM in order to optimize fuel efficiency and power. VTEC was not invented to make your car faster. The fuel effiency is the big kicker. So the reason your car is "slower" with VTEC engaged in the low RPM range is because your air/fuel ratio is all fucked up. VTEC switches = bad idea IMO. Your running too lean in the low RPM range. In the ECU some extra fuel is provided from VTEC engagement to redline. Pull the switch and the motor and go from there. Invest in a HonData s200. I could go more in depth in to the operation of VTEC but I wouldn't want to scare the simple minded newbs. </TD></TR></TABLE>lol
what he said, your only screwing yourself and your car with that switch, it was designed by honda to work a certain way

 

If you keep doing that you will end up buying a new motor(not a bad thing) vtec is set from factory at a set rpm for a reason. This is why tuneing vtec should only be done on a dyno. That way you get the correct a/f mixture. Your doing more harm then good.

 

Let me ask you a question.... Do race cams rune well at low rpm? No of course not thats why your car is slow at low rpms because it swithces to a more aggressive cam profile. I am by no means sayin the secondary cam profile is a race cam though, its just not meant for low rpm's.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B2CivMan &raquo;</TD></TR><TR><TD CLASS="quote">Let me ask you a question.... Do race cams rune well at low rpm? No of course not thats why your car is slow at low rpms because it swithces to a more aggressive cam profile. I am by no means sayin the secondary cam profile is a race cam though, its just not meant for low rpm's.</TD></TR></TABLE>

Lol, He said its a VTEC-E. No wild cam for this ****. It would be running like a normal non-vtec engine.

But the reason why you are slower at low rpm coz your a/f ratio gets fucked up coz the ecu will get confused.

Don't do it coz its pointless. Get a VTEC head or even the 3-stage vtec if you want more top end power yet being fuel efficient at the same time.

 

ok so I thought it was a button that would switch over to the more aggresive profile but it sounds like it just swaps the vtec fuel map with this button?? sounds pretty worthless to me...........

 

Stop screwing around with the engine and get a EX tranny.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PhatBoy5015 &raquo;</TD></TR><TR><TD CLASS="quote">but in case you aren't, here's how it works. When it is not in VTEC mode, each cylinder only operates on 3 valves (1 intake, 2 exhaust), then when VTEC kicks in, it runs on 4 valves (2 intake, 2 exhaust) per cylinder. </TD></TR></TABLE>

this also pertains to the 92-94 VX hatches. E-VTEC... the reason why it runs slower with VTEC on all the time, is the fuel maps. its thinking its still in economy mode, even though your controlling the valves on your own now. the ECU still thinks your in non-VTEC.

the only other option is to convert to a P28, or non E-VTEC ECU, and reprogram it. i have a 92 VX, with a 1.5 Z1 long block, turbo'ed on a P28 and 6 pounds of boost, and VTEC no longer is a problem. (2K RPM activation )

 

because vtec is not a nitro substitute.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B2CivMan &raquo;</TD></TR><TR><TD CLASS="quote">ok so I thought it was a button that would switch over to the more aggresive profile but it sounds like it just swaps the vtec fuel map with this button?? sounds pretty worthless to me...........</TD></TR></TABLE> Ok your just confusing yourself now. VTEC works on oil pressure. When VTEC is activated (by gay *** switches or the ECU) there are "pins" that slide over to lock the primary, secondary and mid rocker arms together. This makes the most agressive profile on the cam functional. When VTEC is disengaged the "pin" slides back and only the primary and secondary rocker arms are functional. The fuel maps are pre-programmed in the ECU to change for VTEC at the stock engagement point. The fuel maps will always stay this way unless you get a Hondata S200 or something similiar. All the switch does is **** up your **** and engage VTEC when it isn't needed and it isn't funtional at an optimum level. Chew on that bone gentleman. Happy Tuning, hope you didn't pay more than $2 for you VTEC switch at radioshack or some ****. I know some guy was selling em on Ebay a while back.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by monicle &raquo;</TD></TR><TR><TD CLASS="quote">because vtec is not a nitro substitute. </TD></TR></TABLE> Yeah, the only substitute for a nitrous can is a bigger nitrous can, LOL!!