OK... trying to wrap my head around this and can't.... need some expert advice. NOT an audible knock...

(PV and TT on 15RGS with 120ST)

I did an AT session yesterday morning to get my VE tables back in tune after changing my pipe from 1074X TH to D&D Boss Boarzilla... runs better now... but.... still having spark knock issues... sometimes both cylinders... sometimes one... not sure why....

I went on a 310 mile ride yesterday... 80- 85 degrees and cruising along at 90-95 and I start getting spark knocks... I did a quick datalog to capture it.... about 50 hits total in 100 miles( not all in the datalog... just a few minutes ). below 80... I don't get but 1 or 2 hits....

ANY insight would be very much appreciated on how to correct this.

Attached is my datalog

Thanks

 

post your spark advance table... you might need to retard it a bit

looking at your log, it seems to be happenning only on the front cyl, and the VE on that cylinder are consistently 10% or so under the rear one, which strikes me as a bit odd. are those values from target tune?

by the way, which engine is this? I looked at the map of my former 2009 dyna and the advance @ 3500rpm, 60kPA is 39 deg... way higher than yours. it did not knock... but my fuel down here is different.

 

I had this issue with the TH as well... just want to cure it for good... if I can....



Sometimes its front... sometimes its rear... sometimes its both.... thats whats weird about it.

this is the 120ST crate motor... Boss Boarzilla... PV and TT. in my 15 RGS

Jamie from FM configured the TT and sent me the original tune for my scoot that I used to AT it...

Here are both front and rear spark tables....

 

one more thing... after AT session.... I exported twice.... first time with scaling..... it bumped my displacement up to 148CI.... second time with the cap....

I am running the first export with scaling.

the only different between the two tunes was the VE tables and displacement. ( difference most likely due the scaling since I have several cells above 127.5)

I have been reading that the SPARK LEARN of the PV doesn't work all that well and haven't tried it yet due to my reads.... whats your take?

 

wow, a 120... that's ought to be a beast

ok, reading from where it knocked the most (around sample 76301) your TP was @ 30%, MAP 61..22, knock retard front 3.75 and the advances were @ 26.5 and 27.5, pretty close to each other but below what your table asks, so I would guess the ECU is pulling timing from both cylinders... notice that your tables are different and there is like 4 degrees less on the rear table on that region you are riding.

in your shoes I would copy the rear table over the front one and see what happens. or perhaps just pull the advances that are higher on the front to the (lower) values on the rear, but not touch the ones that are lower already... timing can be a PITA.

 

First off.....thanks for taking time out of your day to help me out... much appreciated....

I will try copying the rear over the front and see what happens across the board..... if things get outa control... I will just do the region from 40kPA to 80 kPA at 2500-5000 to see if it calms down....

Thanks again for your help....

Have you ever tried the SPARK LEARN with the PV?

 

I did not, as I use the PV on a roadster (on the twin cam I used SEST). Don't think sportsters have the knock detection, I know the older ones didn't ... still learning about this newer one.

 

One more question... what software you using to read the datalog?

 

your posted datalog I opened in Excel.

 

I would maybe go back to Jamie and ask for some help/input on this before you start setting the front and rear tables the same etc etc ...he presumably set the map up that way for a reason so his expert input would serve you better here me thinks.

Regarding the difference between front and rear VE, that has been discussed a few times and often ends up under the "the engine needs what it needs" explanation ...but, have a look at a stock map and you will also see 10% if not more of a difference so that is probably a red herring. Now, whether the O2 sensors are in the right place and giving good data is maybe another question...

If you want a suggestion (and I 'aint a Pro), it looks as if in this piece of log there is an average 1.25, 2, and 3.5º of knock on the front only, in the 50, 60, and 70 kpa columns, in the 3000 and 3500 rpm rows ...you could maybe try retarding your table there by 1,1.5, and 2 to see if that gets rid of it ...and re-visit taking a bit more if necessary.

It looks like this...


DO NOT USE SPARK LEARN ...it doesn't work. Speak to Dynojet and/or FM before even thinking about it. If it does actually work then lets hear from Dynojet/FM about how to use it and when etc etc because people seem to be falling for the koolaid (as they call it)

[really weird that there seems to have been a few posts on PV and spark learn recently ...is there a sales drive going on here, lol ]