Hondata

I have noticed after the first pull on a new base map that when i lift my foot of the pedal to shift there is a weird sound coming from the engine. I immediately stopped everything and looked at the datalog. It seems vtec disengages even at high rpm as soon as i lift of the throttle. I have noticed that the vtec window was set at exactly the same rpm for both boundaries. 5400 rpm.

But that shouldn't make vtec disengage at +7000 rpm only because i lifted of the throttle right?

My laptop ran out of battery so i'm sitting here for charging and wonder if it will go away by setting the upper boundary rpm a bit higher . I kinda dont wanna risk another pull only to find out that it wasn't my actual issue and float the lma again. Is it actually harmful if it happens one or two times?

I found out that the minimum TPS position in the vtec parameter apparently has the bigger priority over the actual vtec window which seems very wrong to me. It was set at 40% and if l let of the throttle less than 40% my vtec disengages NO MATTER WHAT. Even at 8000 rpm which caused my lma to float. I have now set it to 0% and it the noise is gone. When i have the both map values for the vtec window set the minimum tps option is not necessary in my opinion.

Can someone explain the purpose of the minimum throttle option and why does it have the highest priority? This seems dangerous to me.

Have you read the info in the help file: http://www.hondata.com/help/smanager/vt ... htsub=vtec

Spunkster wrote: Mon Dec 14, 2020 10:31 am Have you read the info in the help file: http://www.hondata.com/help/smanager/vt ... htsub=vtec

It doesn't really say something about the minimum tps setting. :(

Post your calibration as well as a datalog showing the issue.

I'm sorry. I one have that one photo of it. Stupid me forgot to save the datalog and i don't wanna damage my valvetrain by doing it again

You can see the vts went to false as soon as i lift of the throttle even tho the rpm is still over my upper boundary of 5500 rpm

I'll post the calibration as soon as i get home if that helps.

We really can't tell much from just a screenshot.

yeah i thought so. I'm fine by the way i have set it up now. I'm gonna post the calibration anyway so maybe there is something set up wrong. But I won't try and capture it on a datalog. My valvetrain would hate me :)

You have no minimum TPS or minimum speed. Compare to any other stock VTEC ECU calibration.

This thread is a little bit old but agree I found similar, I had to remove the TPS constraint in vtec, otherwise I would fall out of vtec between shifts. In my case the effect was I’d bog when I land in the next gear because it would land on the low cam with way too much fuel having been out in for the low cam. It would jerk 2 or 3 times then catch back in vtec and get up and go again. Removing the TPS constraint got rid of the problem. It was pretty clear in the logs the instant the throttle fell below the constraint vtec was deactivated regardless of load or rpm.