pcmhacking.net

If you havnt done so yet you should check that bug exists on the latest tp version, and if it does report it with instructions to reproduce on the tunerpro forums. Mark will fix it.

yeah, I should report that, havn't yet lol.

Anyway, had VE learn enabled for a while and its amazing how well it works, I seen the table slowly evolve and looking a lot more like a pattern each row of curves.

Its vastly different from stock thats for sure.

Also been chasing this knock that keeps popping up in 2 main areas. I got new fuel from a station with high turn over, no real difference.
So I tried an experiment to see if its real knock or false. Its mostly been pegging the max retard value of 9.8º at 95 Kpa (600m up so I can't get 100Kpa ) and 3400 and 4000 rpm areas, sometimes tiny bit at 4800rpm.

So I looked at the spark table and notice the stock table has characteristic curves but with well defined 2 rows of troughs at 3600 and 4400 iirc. The actual whole table is quite choppy in many places so I thought well, engine has obvious spots where timing is reduced on purpose from factory for a reason.

I ended up selecting the 2 areas where I experienced knock(very close to the existing troughs) and looking at the knock retard values in the monitor I could see the value slowly reducing from first knock and then see the next one happen when the retard drops to a certain value. I use that value to roughly work out the maximum timing it can do at the point before a knock happens.

I ended pulling 6º out in those areas. Went for another log and looks like I am heading in the right direction. knock still there but the value of retard has dropped to just over 2º and 4º retrospective. The 4º retard area was at 4350 rpm this time, little bit higher rpm than last time, but looking at the spark table there is a huge jump from 4000 to 4400 so interpolation would give it a high advance compared to the area I was reducing. So if I take the 4400 area down few º as well it should stop knocking there and another 2-3 in the other areas.

Well, performance wise, its better actually. No loss in performance what so ever even with 6º removed and coz the retard values are whole lot less now it doesn't affect areas outside where the knock happens. I might speed up the knock recovery rate too.




I did a 0-100 pull and to my surprise I wheel spun nearly the whole 1st gear lol Yesterday it just kept bogging down.

Bit of insight on these to areas from the same log.

Can see the knock retard, not so bad now on the 0-100 run.
However little bitter earlier in that log session, no knock what so ever.
I looked closely and noticed the advance in there was lower across the range than whats in the spark table where the 0-100 was as per table bar the knock retard.

So I investigated and found the advance subtraction vs coolant temp vs MAP table

At the 87ºc row there is 0 subtraction. In the 0-100 run my coolant temps were at 89-90ºc so no extra retard really.

At 98ºC row at high load areas there is a 3.8 or so º subtraction.

See the monitor, no knock as it was down few º from normal because the temps were closer to 98 and subtraction coming into effect.
Pretty cool, so I'm definitely in the right direction.

Something is wrong if it is only taking 9 degrees wot I run 14 degrees at 21psi of boost .n/a I start at 14 and end at 28-32 degrees

this a VR engine? I run more than 9 degrees at 15psi boost in a stock turboed VR engine... something definitely not right there. even ecotec engines known for taking less timing can run more than 10 at WOT. 9 deg is getting down towards where a hot as intake on an L67 at 12 psi boost needs to be.

what could it be then? everything else seems to be fine.

my intake temp are between 40 and 60, so I don't think thats a problem.

Could it be false knock that some how reduces with reduced timing? I never seem to catch many knock counts but that might coz they are too fast to log?

I don't hear anything externally on the engine when they happen.

So whats a suggested spark curve I should have for stock VR with 98 fuel.

And with knock counts, whats a safe level to ignore? I might try upping the timing and filling the ignore table.

The fuelling looks pretty good

yeah its pretty much spot on across the whole VE table. VE learn is your friend

Ok so I have set up the knock count ignore table at 150 counts from 3600 up.

That fixed that problem then I increased the spark curve few deg over the stock curve.

There is a bunch of knock counts there on takeoff but at that point the car was shaking itsef apart, lot of drive train vibration and what not, revved it too much as well.

Then again I did 90Kpa row as I can't get much past 90, vacuum has increased and air intake restriction if now evident, baro is currently at 950Kpa

I think dyno time is needed now as its evident in these logs tyres are going to cost more Just look at 1st gear now.


Anyway you see the knock counts seem to be random, possibly drivtrain racket and have all but disappeared in the 2nd log despite increasing the timing some. so thinking its not knock at all.

I agree.. I have seen v6's soemtimes go bananas with knock counts and had to disable the knock sensor... I assume due to some other noise setting it off. I wonder why its only at 91kpa at WOT... thats a pretty serious restriction for a v6... is it a stock engine? stock intake and filter setup?

Baro of 95kPa so not as bad as first thought, was going to question the same!

Tuning is looking good vlad01 Changing small things and one at a time to not confuse things