my friend just purchased a vtech controler from apexi he got the new model he was wondering at what rpm range should the hi cams be activated for best performance, we were thinking of activating at 3,000 rpm.. any info will be help full

 

unless he has a lot of modifications, his VTEC!! activation should stay right around 5200...honda placed it there for a reason, lowest i would recommend would be 4800

 

Hmmm . . . I don't remember VTECH making a controller for their phones.

If you're talking about VTEC however, activating it at low RPMs won't help.

 

what happens if it is set at low rpms

 

so there is no need to buy a vtech controller is the car is stock

 

Yeah, Honda didn't spend crap loads of time and money to figure out where to put their Vtec engagement for nothing, they put it there for a reason. As soon as the power in the lower cam profile starts dropping out thats when they switch to the higher cam lobes, so if ur car is mostly stock I wouldn't reccomend changing it, and just to keep u from getting flamed on by ppl, It's Vtec, not Vtech, Vtech is a phone and ppl here on Honda-tech kinda like to pick on new ppl for saying that. For ur car I'd just start getting some simple bolt ons if u want some slight better performance hp upgrades.

 

Well if he installs a v-tech controller, maybe he can make long distance calls while driving his car?

 

thanks man and i'm sorry about ABOUT SAYING VTECH I MEANT TO SAY VTEC but thanks for the insight

 

Don't worry bout it, everyone gets it wrong the first time , we know what u ment, good luck with whatever u do too, if u need anymore help or insight, just ask.

 

u need a dyno to determine where vtec should be placed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JasonST &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, Honda didn't spend crap loads of time and money to figure out where to put their Vtec engagement for nothing, they put it there for a reason. As soon as the power in the lower cam profile starts dropping out thats when they switch to the higher cam lobes, so if ur car is mostly stock I wouldn't reccomend changing it, and just to keep u from getting flamed on by ppl, It's Vtec, not Vtech, Vtech is a phone and ppl here on Honda-tech kinda like to pick on new ppl for saying that. For ur car I'd just start getting some simple bolt ons if u want some slight better performance hp upgrades.</TD></TR></TABLE>

Did you quote that from me? Up till the flame part, that's about word for word what I tell people

 

yes please ignore me
I'll be glad to help you with whatever I can if you need it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98vtec &raquo;</TD></TR><TR><TD CLASS="quote">u need a dyno to determine where vtec should be placed.</TD></TR></TABLE>
x2

 

just leave it alone...like they said before...its there for a reason.

 

i understand what everyone is saying but when you make the arguement that honda spent lots of money to put vtec where it is best.... they also think about fuel economoy and also reliablity. Wouldnt lowering vtec cause gas milage to go way down which is somethin hondas have always been good with, gas milage. Just something to think about im not saying anyone is wrong just figured i would throw that out there.

 

well, normal driving for me doesnt include the high cam, which crosses over at 4800

 

true and thats what i mean. Vtec settings may have been put up high for fuel economy if fuel economy was not an issue and performance was the only thing that was trying to be acheived do you think they would have put it at that point ? Im asking not being a smartass

 

i suppose they were trying to get the best of both worlds. Economy and performance. Considering the prelude wasnt built to be a "fast" car, thats what i would conclude.

 

Answer a couple questions

Putting VTEC that low 3,000 rpms would have a much more negative effect. I'd say you should expect a power loss if anything not to mention bogging etc and ofcourse worse gas mileage. Technically I believe your supposed to put VTEC where your horse and torque cross which is usually around 5,200 for best performance unless you have a lot of mods which would change your dyno. I also doubt they put it that for better gas mileage because if i'm not mistaken the manual recommends shifting at ~3,900rpms for best gas mileage which would leave them plenty of headroom for setting if lower if they wanted. Keep his VTEC ~5,000rpms....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94Vtecluder &raquo;</TD></TR><TR><TD CLASS="quote"> bogging </TD></TR></TABLE>
seems like the first thing thats extremely noticeable

 

Guys, it's Veetak.

Someone needs to make a sticker with V-Tech next to a phone and VTEC with a tach.

 

yeah unless you have some headwork mods, cams come to mind, that changes the entire ramp of hp/tq the stock point is where the primary lobes drop off like everyone is saying...why would you want to not maximize the whole stock cam? just so you can do a "vtec flyby" everytime you take off from a light? yeah thats gonna earn you lots of respect...

 

i had a vtec controller in my 98 prelude and i didnt dyno it so everytime i hitted vtec it would lag and i had a APEXi VAFC2, and i set it to hit vtec at 4800 rpm's but really hatted it sometimes of the lag cuz it wasnt tuned

 

this is straight out the honda manual.. this is what honda engineers say...


In general, it would be ideal if the high rpm performance of a racing engine and the low rpm pertormance of a standard
passenger car engine could be combined in a single engine. This would result in a maximum performanc€ engine with a
wide power band. Two of the major differences between racing engines and standard engines are the timing of the intake/
exhaust valves and the degree of valve lift. Racing engines have longer intake/exhaust timing and a higher valve lift
than standard engines, The Honda Variable Valve Timing and Valve Lift Electronic Control System takes this into account,
Wh€n valve actuation is set for low rpm timing and lift, low rpm torque is better than in a standard engine. When
valve actuation is then switched to high rpm timing and lift, output improves to the level given by a racing engine. Until
now. few variable valve timing systems have been commercialized, In those that have, only the time that both valves are
open (intake/exhaust overlap) could be changed. Honda's system is the first in the world in which both the valve timing
and the degree of valve litt can be changed as needed, making it the most advanced valve train mechanism available.

thats why v-tec is set for higher rpm

 

actually alot of times when you install new cams, especially with modified nonvtec lobes you do not want to shift vtec lower even then with heavy mods, I have a built motor I am using crower stage 3 cams in and I set my vtec to 5250 because the vtec lobes are still to large even with the modified motor for lower rpm