i have a 98 GSR and i know VTEC engages at 4400 RPMs and the secondarys open around 5700 RPMs or something close to that, but i was wondering in deceleration at what RPM does VTEC disengage?

Low cam - High cam = 4400

High cam - Low cam = ?

 

I would imagine just the reverse.

butterflies close back at 5700, and vtec disenages at 4400.

 

i think it disengages lower than it engages but im not sure?

 

I dunno why it woulddo that...

Why does it even matter?

 

because im in the process of tuning my VAFC II and i need to know when VTEC disengages on a GSR

 

bump can anyone help?

 

it should be the same, but vtec also disengages if ur less than 50% throttle.

 

unless youre over 5500, vtec is engaged no matter what.

 

ttt

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 401tuner &raquo;</TD></TR><TR><TD CLASS="quote">i think it disengages lower than it engages but im not sure?</TD></TR></TABLE>

go out and drive your car and see... I really dont understand why it would engage at one rpm and disengage at another rpm....
Chances are its at thesame rpm both ways.

 

wow vtec engages at wot at 4400. half throttle at 5000. butterflys at 5800. and disengage at 5800. i duno about the vtec disengagment point casue i always drive in vtec but i would set the engage and disengagement at the same point.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 401tuner &raquo;</TD></TR><TR><TD CLASS="quote">because im in the process of tuning my VAFC II and i need to know when VTEC disengages on a GSR</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bildo16 &raquo;</TD></TR><TR><TD CLASS="quote">unless youre over 5500, vtec is engaged no matter what.</TD></TR></TABLE>

what?

 

yeah.. he totally worded that backwards, rofl. I didnt catch it til you said soemthing.

which is wrong anyways..once youre at 4400 vtec is engaged no matter what.

but he was responding to the person above who said vtec disengages if you are partial throttling it.

 

because they wont let the disengagement point be higher than the engagement point. so yea idk i have the engagement point at 4500 rpms and disengagment at 4000, hopefully thats alright

 

before i upgraded to skunk2 manifold vtec was 4400 secondary was 5750 and when i was half throttle vtec would hit 4800 rpm.

 

on my VAFC II i have my vtec set at 5700 rpm and dissengage set at 5600 rpm, dont ask me why, my buddy with a type r has his set at that and told me to and it works fine.I actually like having it set at that point because i can actually feel my vtec kicking in, the stock settings i couldnt feel it kicking in but you could notice acceleration, but now i can feeeeeel it crack.thats just my 2 cents.

 

wow i never thought of putting it that high, im sure you can feel it because vtec kicks in and the secondaries open at the same time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by numbnuts22715 &raquo;</TD></TR><TR><TD CLASS="quote">

go out and drive your car and see... I really dont understand why it would engage at one rpm and disengage at another rpm....
Chances are its at thesame rpm both ways.</TD></TR></TABLE>

VTEC engagement does have a hysteresis. You don't want to keep engaging/disengageing when you hover near the setpoint. This article for the ITR highlights the conditions for the USDM B18C5. I have not seen it for the GSR. These should be in the ECU code.


The last page of the ITR article states VTEC as 5700(engage)/5400(disengage) for WOT and 5900(engage)/5600(disengage) for partial throttle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91DBSexyTime &raquo;</TD></TR><TR><TD CLASS="quote">on my VAFC II i have my vtec set at 5700 rpm and dissengage set at 5600 rpm, dont ask me why, my buddy with a type r has his set at that and told me to and it works fine.I actually like having it set at that point because i can actually feel my vtec kicking in, the stock settings i couldnt feel it kicking in but you could notice acceleration, but now i can feeeeeel it crack.thats just my 2 cents.
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does it bog out or fall off of vtec when you shift from 1st to 2nd?

the vtec engagement seems way to high for it to be good, the itr can get away with it being the higher final drive that it has. (well, depends which itr he has )

i would just ditch the vafc and get a hondata and do it the safe way and let some pro who knows what hes doing work on it.
same goes for the OP

the vtec on GSR`s are meant to stay at 4400, where HONDA intended it to stay, unless otherwise you change cams and tranny than you should deff. look in to a hondata or tune on crome.

i just don`t see myself messing around with the ecu and not knowing shiat and asking a whole bunch of noobs here on H-T. :shrugs:

and that is my .02 cents

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91DBSexyTime &raquo;</TD></TR><TR><TD CLASS="quote">on my VAFC II i have my vtec set at 5700 rpm and dissengage set at 5600 rpm, dont ask me why, my buddy with a type r has his set at that and told me to and it works fine.I actually like having it set at that point because i can actually feel my vtec kicking in, the stock settings i couldnt feel it kicking in but you could notice acceleration, but now i can feeeeeel it crack.thats just my 2 cents.
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feeling it kick in means it's at the wrong point. vtec should be a smooth transition from low to high cam.

 

meh whatever, i plan on building another motor anyways, and the vtec doesnt bog at all, everything runs normal on my car and ecu except the ecu is starting to act gay, bought ready to chuck it out the window.

 

they should be the same

 

u answered u own question