For anyone who hasn't seen my posts, I have been rebuilding my Hondata calibration for the past year from a corrupted tune. I've got it mostly dialed, but as I get more confident and push the car further I start running into more questions.

Now I am focused on my tip-in trim setting. When I downloaded the original map it was at -20%. I questioned this because it seemed excessive, and from reading around the theory is that this should be a positive number as the fuel reaches the cylinders more slowly than air when the throttle is opened.

Problem I am having is in between shifts, which is probably the only time I open the throttle fast enough to activate this, I get a studder/misfire and it reads full rich for a second before it starts accelerating again. This is with the trim value reduced to -15%, because again, I thought 20% seemed excessive. I also had noticed on my logs that if I did say, a pull only in 3rd gear, when I first step on the throttle but not as quickly, it would read a bit lean until the MAP stabilized, so I wondered if this was the cause.

I then tried changing it to 0% just to see what would happen, and it got worse. So I figure I will go the other way and switch it back to -20%. But does this seem normal? Can anyone explain the logic behind it needing so much negative tip in? Concern is that it will cause a lean spike when still under boost somehow.

Also, here are the TPS tip in settings.... Are these the ms that the tip in is active?

 

I think I might be getting it figured out, but not too sure. It seems to behave differently if I mash the throttle in gear vs. when changing gears.

Right now I think it wants to be somewhere between -5% and -10% for making a smoother 2nd to 3rd gear shift without the hesitation. There is no big shift in the datalog AFR doing this.

BUT. If I am in 2nd or 3rd rolling along and step on the throttle, I log about 0.2 seconds where it leans out.

 

So load vs no load there's a difference? Do you have a trim by gear setting? Neptune does, not sure about Hondata.

 

 

So, if I got it correct. Sounds like 2 concerns to look over. The throttle tip-in handles corrections when you either hit or let off the throttle, yeah? Then the throttle under gearing seems to be load condition based. Either by gear or fuel compensation at various IAT/ECT points under given load; low, med, high? May not have typed out what was on my mind correct, but sound right?
So check corrections by gear, if any, and check IAT/ECT fuel compensation under load.

 

I checked out my gear based compensation and everything seems okay there. I think I figured out the actual issue is my VTEC engagement and where it is reading from on the fuel maps.

So when I stay in one gear and pull from say 4k rpm up to redline, I get a clean VTEC cutover at 5250rpm and it always reads from the same parts of each fuel map.

BUT, when I am shifting gears, depending on where I shift the RPM falls to right around the VTEC engagement point, sometimes slightly under. Looking at my logs, sometimes my VTS will read ON for a split second even when below the engagement RPM and back on throttle. The result is that it is reading from a different part of the high cam map that I haven't really tuned yet.

Sometimes between shifts my VTS will go off and back on twice before holding steady. I think this is really the issue and not the throttle tip in trim.

I wonder if the correct way to take care of this would be to first raise my VTEC engagement RPM to 8000 and tune just the low cam map. Then lower my VTEC to like 3500 and tune just the hi cam map, before finally resetting it to 5250?

 

That would make sense under your current circumstances. The process you mentioned for tuning the separate maps is supposed to be the textbook way to do it. Oddly enough, going through my e-tune process with Phearable, we did not do that. They just set my engagement point and we left it there. It never changed after that. Looking over the logs and the info you gave me previously, that point looked spot on too lol.
However.. Any other ways to test your current theory? (Possible intentional recreation of the issue) It makes sense to me, that's where i'd go next!

 

Pretty sure I got it figured out. I spent the last hour tuning each cams fuel map individually as described earlier.

My 0 to 4psi columns on my hi cam map were wayyyyy too rich. I had to take them down like 15-20% just to get them to read on the wideband. What would happen is, after a shift my boost would fall off briefly, and for that split second it would read from those columns until it spooled up again.

Previously I had only tuned WOT pulls on the high cam, and anytime I would hit VTEC I would already be at full boost. The lowest boost I tuned at for WOT was around 10psi, so these lower columns were never adjusted.

 

In the TPS tab, what is the "delay" set to under fuel overrun (TPS)? The default setting for this is usually 600ms, which is WAY too high, and will throw everything off when shifting. When this value is set too high, it will usually make it seem like tip in is way too rich when shifting, but normal when just coasting for several seconds and then stabbing the throttle.

 

 

that's exactly what it is. But remember, that's 0.6 seconds of fuel still being injected while at 0% throttle. It pools, and throws off tip in readings by quite a bit. Try setting it to 150. You may be pleasantly surprised at the results.