Hi all,
Newbie here, although not new to other Honda/Acura forums. I have a question: Does anyone know when the VTEC kicks in on my car? It's an 05 Accord with the 2.4L DOHC i-VTEC engine (K24A4).

Thanks,
Slats

 

i-vtec is variable engagement point

 

ah thanks, but that wasn't what I was asking. I'm trying to find out when VTEC kicks in in my car (changes to higher cam profile)....i.e. 4500 rpm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slats &raquo;</TD></TR><TR><TD CLASS="quote">ah thanks, but that wasn't what I was asking. I'm trying to find out when VTEC kicks in in my car (changes to higher cam profile)....i.e. 4500 rpm </TD></TR></TABLE>

right, and what im telling you is that the vtec cam will kick in at variable points. it can engage at 3500rpm or at 4700rpm or at 3900rpm. its based on a number of factors, of which RPM plays a minor role.

 

So in that respect you are saying it is different than older VTEC systems? That doesn't make sense to me because even the new Civic Si with i-VTEC switches cam profiles at 6K regardless -- they say the variable stuff just smooths out the transition.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slats &raquo;</TD></TR><TR><TD CLASS="quote">So in that respect you are saying it is different than older VTEC systems? That doesn't make sense to me because even the new Civic Si with i-VTEC switches cam profiles at 6K regardless -- they say the variable stuff just smooths out the transition.</TD></TR></TABLE>

the k24 in the accord only has vtec lobes on one side.....so in essence, its really a SOHC Vtec on a DOHC motor.....and just like the f22b1 and f23a's, the vtec engagement point can vary based on oil pressure, manifold pressures, throttle posotions, thermostat/temperature, etc.

if you remover the resonator on the intake, you'll be able to hear it every time it engages

 

Well that really sucks...ok, thanks for your help.

 

why does that suck??

vtec isnt designed to make more power...its designed to allow the car to be more fuel effecient, and only make its most power when the motor is pushed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fw190bvi &raquo;</TD></TR><TR><TD CLASS="quote">why does that suck??

vtec isnt designed to make more power...its designed to allow the car to be more fuel effecient, and only make its most power when the motor is pushed</TD></TR></TABLE>

True, I think im finally understanding what VTEC is too. ITs bascially Honda letting the user save gas and when the user wants to push the gas it engages vtec so its more torque and uses more gas for power. And it makes a nice sound.

 

Click this link and educate yourself a little bit; there ARE 4 variables that decide when the V-Tec engages
http://members.troublecodes.net/hondadude/vtec.jpg The Honda training modules do not lie

 

correct.

 

Here is the basic controls for the i-Vtec

The RPM switching is a myth, when I was at the dealership i had to explain this all the time to people that wanted the V-tec engagement "adjusted"

 

LOL! I find it annoying when a lot of these honda drivers refer to the vtec cars to be faster b/c of the vtec. Some may be misunderstood like this threads poster, but when Ive tried to correct them Im wrong when I tell them that their D16 isnt a performance motor from the factory and that other manufacturers use variations of variable valve timing. VTEC is mainly about the fuel economy thats what Ive always said. and if I really am wrong then I await my correction.

"Yo the VTEC in GSR's crack twice so thats probably why they're so quick." Thats what I overheard at Wendy's today. I just ignored them. lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thedarkone &raquo;</TD></TR><TR><TD CLASS="quote">
"Yo the VTEC in GSR's crack twice so thats probably why they're so quick." Thats what I overheard at Wendy's today. I just ignored them. lol</TD></TR></TABLE> Ditto- most ricers think vtec=nos=supercharger=my d16 has soo much m@d torque yo=im a tard.

 

What people don't realize is that almost every company has their own version of Vtec now.....Toyota, Mazda, Ford, Chevy, Mitsubishi, all have the same purpose, even if Honda's is still a little bit better because they developed it first.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thedarkone &raquo;</TD></TR><TR><TD CLASS="quote">LOL! I find it annoying when a lot of these honda drivers refer to the vtec cars to be faster b/c of the vtec. Some may be misunderstood like this threads poster, but when Ive tried to correct them Im wrong when I tell them that their D16 isnt a performance motor from the factory and that other manufacturers use variations of variable valve timing. VTEC is mainly about the fuel economy thats what Ive always said. and if I really am wrong then I await my correction.

"Yo the VTEC in GSR's crack twice so thats probably why they're so quick." Thats what I overheard at Wendy's today. I just ignored them. lol</TD></TR></TABLE>

yes yes yes, I hate it when I walk past people and hear them saying stuff about cars, not even hondas in particular... and it makes no sense. I HATE IT. Cant stand it.

Ex: "Yeah the VTEC in my protoge makes it rev so high, to like 11,000!"

YES YOU READ CORRECTLY, VTEC IN A PROTEGE, REVS TO 11,000. WTF HAHA

 

thats hilarious...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondaccord2000 &raquo;</TD></TR><TR><TD CLASS="quote">even if Honda's is still a little bit better because they developed it first. </TD></TR></TABLE>

actually they were not the first to develope the idea of variable valve timing...GM first developed the technology in the 1950's...however it was never introduced into a production vehicle...Fiat was the first to use variable valve timing in their 1970 Spider...Honda and BMW both started experimenting with the technology in the 1980's...Honda's was the first to market however, in the 1989 Civic B16A motor (jdm)...the first usdm car to carry a car utilizing vtec was the 1990 NSX however...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thedarkone &raquo;</TD></TR><TR><TD CLASS="quote">VTEC is mainly about the fuel economy thats what Ive always said. and if I really am wrong then I await my correction.
</TD></TR></TABLE>

It is about fuel economy, to an extent...It's actually about efficiently allowing air into the motor...at low rpm's, a longer intake runner and low lift increase the intake charge velocity...this in turn has an effect on the atomization of the fuel going into the intake manifold and creates a tourquier, more usable low end of the power-band...however, the low lift of the valves and long intake track create a motor that can't rev high (runs out of breath in the high rpm's, as it becomes inefficient)...thus, at a selected rpm (different for every motor depending on displacement, piston speed, etc.) the motor switches to a high-lift cam profile to allow the engine to breathe more efficiently in the upper rpm's...this system was so "ingenius" because it was able to maximize the usability of a 4 cylinder motor...you could now have a motor that was decent in the low rpm's but still made nice power in the upper rpm's...this is why vtec became the hit of 4 cylinder engine tuning...

also, the vtec name that honda gave this system is a large result in its success...something about vvt-i and mivec that just don't sound nearly as cool as vtec...

 

good info glad i looked at this

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by C_I_V_I_C_V_T_E_C &raquo;</TD></TR><TR><TD CLASS="quote">good info glad i looked at this</TD></TR></TABLE>

right on man, made me think about vtec.... not all that special hahaha