My backround is mainly integra and the "older" vtec system. It was a rule of thumb not to engage vtec on a cold engine but to wait a good 15-20 mins of driving to get it to operating temperatures before reving high enough to engage vtec. Is this because of the actual vtec unit itself? Oil? Thermal expansion of the pistons/rings/cylinder wall?

Basically does our car need a warm up period before reving past 5-6k?

 

Well its pretty much a golden rule to let your car warm up before you start ripping on it, its bad for your engine, plus i dont think it engages as well when not properly warmed up

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tam N &raquo;</TD></TR><TR><TD CLASS="quote">My backround is mainly integra and the "older" vtec system. It was a rule of thumb not to engage vtec on a cold engine but to wait a good 15-20 mins of driving to get it to operating temperatures before reving high enough to engage vtec. Is this because of the actual vtec unit itself? Oil? Thermal expansion of the pistons/rings/cylinder wall?

Basically does our car need a warm up period before reving past 5-6k?</TD></TR></TABLE>

I wait until my car warms up before taking it over 3000rpm.

You will notice that when your car is cold, VTEC will not engage, and instead just fall flat on its face when trying to accel.

Now that I have the S/C w Hondata/Comptech reflash, I get the same effect, but at a much lower rev, because VTEC engages at 3000rpm under load.

Basically stated, just let your car warm up before trying to rev into VTEC.

 

Yeah, common sense tells you to not push your car to its limits when its cold. Just wait a couple of extra minutes before you stomp on it.

 

Vtec will NOT engage if the engine is not at least 3 bars (if that) on the H-C gauge

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Type X &raquo;</TD></TR><TR><TD CLASS="quote">Vtec will NOT engage if the engine is not at least 3 bars (if that) on the H-C gauge</TD></TR></TABLE>

Yes, any VTEC motor needs to be warmed up before the ECU will activate VTEC. There is also a safeguard so that if your oil level it low VTEC won't engage as well.

 

Vtec requires three inputs to be correct before it will kick in... temperature, oil pressure, vehicle speed

 

yeah I was new to VTEC when I got my SI coming from a non vtec teg and I didnt know and I was wondering why I would punch it and the car would fall flat on its ***. then the dealer told that oil pressure and temperature needed to be at certain levels and he said it takes a few minutes.

 

Not saying that I rip on my car when its still cold. But does vtec not engage if its cold on my 93 Si? Or is it too old for this to happen?

Just curious

 

same in 93

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CodyC142 &raquo;</TD></TR><TR><TD CLASS="quote">Not saying that I rip on my car when its still cold. But does vtec not engage if its cold on my 93 Si? Or is it too old for this to happen?

Just curious </TD></TR></TABLE>

Same as stated in my post above. Just a safety feature for the retards out there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">temperature, oil pressure, vehicle speed </TD></TR></TABLE>

You gotta be pushing down on the gas more than 1/2 way too

 

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

You gotta be pushing down on the gas more than 1/2 way too</TD></TR></TABLE>

that's right... I forgot tps sensor..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IT GUY &raquo;</TD></TR><TR><TD CLASS="quote">Vtec requires three inputs to be correct before it will kick in... temperature, oil pressure, vehicle speed</TD></TR></TABLE>

or chip your ECU w/crome, etc. and have it engage without regard to any of those inputs

not the best thing though