Knock on shifts

FlashPro questions & answers specific to the FN2 European Civic Type R
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mladjan
Posts: 120
Joined: Fri Sep 23, 2016 7:16 am

Knock on shifts

Post by mladjan »

I was working tonight on my calibration and there is few things that are bothering me. One of them is sometimes, one knock per shift in high rpm.
My theory is because ignition is jumping from 19 degrees to 26 on second, and returning back to 19. This value 26 was even bigger, and I tried with reducing this part of the map, but its the same. Its not happening on every run, but its pretty consistent.
Another theory is that vibrations are fake, from transmission. I have blue polybush engine mounts, so engine is not working too much on shifts.
Also, ignition cylinder trim has some retard for cylinder 3 in the basemap. I wasn't touching that, but was planning to put all 0 because I don't need to fix problem with isn't existing. But all knocks I see are on cylinder 2.

Map and the log are attached.
Attachments
LATEST- Race v1.7 - all maps.fpcal
(20.25 KiB) Downloaded 114 times
latest run with few knocks.fpdl
(651.07 KiB) Downloaded 130 times
typer86
Posts: 342
Joined: Sun Oct 28, 2012 3:17 pm

Re: Knock on shifts

Post by typer86 »

I checked the knocking sensitivity high table. And your noise sense was a Little bit to low for the highspeed section.
So I dont think it knocks.

I have adjust the Setting. Additional you have reduced a lot the ignition advace so maybe the fuel will be ignite in the exhaust.
It is not recommended to advance and retard the igntion to much.

In the attached calibration I have configured a good/stable ignition Profile for the K20 rotrex build.

Please try it and check/watch the AF.Corr value (0.80/0.81 from col. 10 to end)
LATEST- Race v1.8 - all maps.fpcal
(20.2 KiB) Downloaded 132 times
mladjan
Posts: 120
Joined: Fri Sep 23, 2016 7:16 am

Re: Knock on shifts

Post by mladjan »

Thx, I agree about ignition advance, and was planning to play with it first on street and after that to test it on dyno to find the best power.
mladjan
Posts: 120
Joined: Fri Sep 23, 2016 7:16 am

Re: Knock on shifts

Post by mladjan »

I just used ignition tables from this calibration and it was knocking on 24degrees in high revs. I removed 1 degree on whole boost section and 1 degree from 7k up (because was knocking after 7k rpm). I tested multiple times and there are no knocks, until last night. I wasn't logging, just live viewing on hondata mobile app over bt (on my double din) and saw 15-20 knocks after few runs.

My calibration is attached. To be honest, Im wondering is this normal to knock in these condition? I was planning to try colder plugs too (ordered set of 2668 NGK BKR8EIX). I know its hot right now (35+ C during the day), but it wasn't knocking when was hot on dyno, but knocked last night when it was colder.

Or there is something I should do with Knock tables?
My setup is:
k20z4 with c38-81 supercharger. Engine is stock (cams, internals etc), exhaust header is aftermarket, full straight single exit exhaust 70mm. It has polybush enging mounts which affect "vibrations".
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