Whack your map !!

sounds crazy but totally works.

https://www.s2ki.com/forums/index.php?showtopic=209708

 

there's some not so good advice in some of the above posts, so i'll try to give you some appropriate info.


first, if you can go above 6000rpm, then VTEC is working. If it wasn't, you'd never get on the hi-cam profile and you'd get a CEL, and you'd hit a rev limiter around 6000rpm.

VTEC kicks in at about 6000rpm. However, this can vary with temperature, altitude, and even throttle position. But in normal conditions, WOT, it's about 6000rpm.

 

Is there a way to get Vtec to kick in earlier, and if so will this do any kind of harm to the engine?

 

Yes you can make it kick in earlier with some tuning (V/SAFC). I think there is mixed feelings about how good it is for the car, but generally the engine should not have any harm as long as its tuned right.


So anything above 6000 RPM is the high cam? I was under the impression you had to be near WOT for vtec to changeover.

 

yup

 

thanks wisconsins2k for clearing it up!

 

I agree with Wisconsins2k but I have to admit, when i bought the car you could feel a noticable surge if you are maintaining a constant acceleration and the vtec kicks in. (understanding that "constant acceleration" is an oxymoron, but sounds better than "plant your foot to the floor at 3000 RPM and hold it past 7500 RPM")

at one point, that "surge" when away and the power felt more linear through the rpm range.

I addressed the issue with the Map sensor whack from the Under the Hood forum and the "surge" returned.

 

my car has been idling a little funky...i'll have to try the map sensor whack...

 

believe it or not, the ECU DOES use the TPS as one of the many sensors/determining factors as to when it engages the hi-cam profile. (God forbid slowS2k read this thread) in fact, it even uses vehicle speed sensors. if memory serves me correct, if the car is at a standstill (ie stopped and in neutral) the hi-cam won't engage, even though you can redline to 9000rpm.

and technically VTEC doesn't "turn on" or off for that matter. VTEC is the name of the variable timing system honda uses. what actually "turns on" is the hi-cam profile on the cam shaft.

 

in stock form, you will not gain much by lowering the hi-cam profile engagment point. in fact, it could slow you down. I'm not going to take the time to explain the entire VTEC system right now though, as I dont feel like typing all of that out.