Knock Sensor Went To 75-help

[paulr33]

ok first off try -2 deg next time and see if you have similar results

its likely (almost always) that in one or two spots on the map the timing is a little too far advanced for higher intake temps. as the warmer nights and weather approaces the intakes temps are a bit higher. what airtemp are u seeing under MONOTOR, 1 CHANNEL, AIRTEMP when you are seeing the knocking over 60 with normal -0 deg timing adjustment?

If we find -2deg is ok then we need to work out where on the map its knocking, which isnt too hard and I can walk you through it, or if you like we can meet up and do it, upto you. its probably better if you learn it that way u can control and decide what to do.

so

1) try -2 deg see how that goes, note what knocking you see

2) try -0 deg (no correction) see how that goes, note what knocking you see and airtemp

[paulr33]

Set back ign as paul indicated......car runs smoother and has not missed tonight.

Even going up hill i planted it and all was good...excellaration came on nice and strong.

good this shows its most likely timing related

Paul, can I set back the ign by -2degree permanently and see if it happens again?

you can't easily with the hand controller, you need to edit every value or keep using the temp adjust.

the real thing to note here is its only knocking in one or two spots, so it would be un-necessary to drop the whole map 2 deg. you have a 20x20 cell for your ign so it would pointless to edit 400 values and take out 2 deg. once we work out where the bad spots or cells are, we can take out 2deg for those, instead of the whole map (think of an excel spreadsheet)

Should I use one of your saved tunes instead and modify it to my mods?

This is a bad idea and will likely make it worse or amplify the pinging/knocking/detonation.

you should under no circumstances load someone else's map. the only time you would do this is if you were experienced in watching and checking for detonation and had a wideband sensor handy.

And has the tune been conducted in colder weather and this is why this has happened?

Its likely just a combination of increased intake temps and a few cells a bit too far advanced

under colder weather they are fine but under warmer weather predetonation is more likely

its no big deal and easily fixed so don't stress

[700HP-GTR33]

Hello Paul,

The knock that occured at 75....was recorded on around 5000 through to 5500 did not push through

More than likely it it would have still been occuring at higher revs.

28 degrees is what the hand controller read.

The car also has a better idle as stated earlier.Do I only change the Ign timing below 1500RPM then?

I would like to meet up at a later date....thanks a million for your help.

Cheers

[700HP-GTR33]

The Op's has been having a miss problem; likely to be related to ignition. Your ignition system clearly is perfectly fine and your det is simply too much ign.

As I mentioned with shagged coil packs on 2 different cars I have observed an increase in knock over what was before a perfect low knock tune in all conditions.

Most likely not the case here and most likely just a tune issue. But I thought it would be usefull to mention it.

75knock really is too high, might be worth taking the car back for a touch up as a load condition may have been missed when it was on the dyno. It is difficult to simulate road conditions on a dyno; which is why its so important the tuner takes it for a quick spin. From what I've seen the dyno tends to miss partial throttle on boost load points and low rpm high gear (up hill) lugs where it makes reasonable boost; even though on the dyno we did hit these load points on the road it was 'just different'.

That is correct....heavy throttle just about to climb low revs(3000).in fourth gear.

That is where it happened.ok till I hit 5000rpm did not like it after that.

But this does not explain why the idles lumpy,infact previously I though it was the idle.

So I increased it to 930RPM using the PFC....this did not change the roughness.

I will give -2 a go tommorrow mornong and see if this also is good.

if this is also fine.....I will try -1 and so on.

Stay tuned....

Cheers Tekin

[paulr33]

no problems. let me know how you progress. when using the temp ign adjust it will actually change the idle timing so you can "invent" lumpy 'cammed' idle by using the temp ign adjust. on the IGN map the PFC ignores any timing u set for idle so at cell 2x2 you can put say 22deg IGN timing and it wont apply it to idle. idle is always 15deg base. but if you use temp adjust, it actaully applies to idle so if you do -2 your idle comes out at 13deg which will give it a lumpy gurgle idle, so don't stress too much.

The same occurs if you have someone dial the crank angle sensor back as a temporary "retard the timing hack". As the PFC just expects base timing to be right it applies 15deg but if the CAS is backdialed a bit its actually a bit less. mine is like this, so i have lumpy gurgle idle, its amusing but neverthless thats how it goes (at least how i understand it, and seen it work)

[700HP-GTR33]

OK -2 today...noticed some missfiring between 2800RPM and 3100Rpm under slight load.

Idle is ok but not as good as yesterday,s -3.

What does the graph represent in the ign/timing area?

20/20 grid is horizontal?...vertical?

[paulr33]

someone else asked me the same thing this morning

so ive got the hack up diagram i did

its basically the 20x20 map

across the top row is revs

and down the left side is engine load (or airflow)

as the engine goes through changes in its environment (rev & load) it will move around on the map.

at any one time it can only use 1 cell at any given time. u can use map tracer (under MONITOR) to see what cell is currently being used. the highlighted cell indicates what cell on the 20x20 map is being used for INJ and IGN

so say at 3523 and airflow load is say 33% of the AFM max (left row is not AFM voltage)

then it will somewhere near load point say 8 for rev

and somewhere near say load point say 7 for load

so on the map we are position 8x7

[700HP-GTR33]

Thanks Paul,

I will use Map tracer to identify the exact point at which I am having the problem.

It is obvious it is at more than one location.

I will then note the figures and their value and take 2 off the ignition timing on the exact point

and 1 on both sides of that point.

Or should I take 3 off the point ,2 the next 2 point either way and then 1 point off the 2 point either way?

Cheers

Tekin

[700HP-GTR33]

Hello again,

I have been driving around trying to pin point the exact position on the map tracer.

I believe the tracer is in-accurate, when the hand controller is reading 940rpm when I have stopped the

map tracer is reading that I am 400-800RPM.That is the first set of figures.

Infact the timing is 15 at that point but the hand controller is stating I am at 20odd+

Anyway having said that at 4th gear 2570RPM at low throttle I had a miss today have not changed

anything and adj.was set at 0.

Have tried to duplicate the event at higher RPM(as this is where the knock75 occurred) and have been unable to.

The weather is cool and that may make a diff.

Paul,

Can the temp. setting on the FC have some sort of impact on the IGN/TIMING?

I am going to decress all the figures by one on the ign/timing at 2400/2800.

Is this ok?

Then I will see if the miss occurs again.

Cheers

Tekin

[paulr33]

Hello again,

I have been driving around trying to pin point the exact position on the map tracer.

I believe the tracer is in-accurate, when the hand controller is reading 940rpm when I have stopped the

map tracer is reading that I am 400-800RPM.That is the first set of figures.

The map tracer is fine and accurate, it does do cell merging that is if you are say at 850rpm

it may use the values for 400-800 and 800-1200 and do an average between the two cells.

Map tracer can only show you one cell so it simply shows you one call. This is more obvious with datalogit as it shows crossing of the load points.

Infact the timing is 15 at that point but the hand controller is stating I am at 20odd+

The base timing is 15 deg but the hand controller may show 20deg on the IGN map.

If you are referring to the idle IGN timing that can't be adjusted and whatever value is at 2x2 is ignored by base idle.

Anyway having said that at 4th gear 2570RPM at low throttle I had a miss today have not changed

anything and adj.was set at 0.

Have tried to duplicate the event at higher RPM(as this is where the knock75 occurred) and have been unable to.

The weather is cool and that may make a diff.

Whilst its possible that for one day you may not be able to replicate the knocking/misfiring and another you can its a case of pick the most logical spot and take out 1 or 2 deg timing. You won't notice maybe 1 or 2deg timing but it will make a bit of a difference if its knocking under load.

Paul,

Can the temp. setting on the FC have some sort of impact on the IGN/TIMING?

I am going to decress all the figures by one on the ign/timing at 2400/2800.

Is this ok?

Then I will see if the miss occurs again.

Cheers

Tekin

By the temp you mean Airtemp under MONITOR?

The FC has default retarding based on airtemp but its for like 50+deg intake temps, that is, it will take out timing on the whole map when intake temps are over 50 and so on. I think the defaults are 0deg retard for each braket. So if you are seeing intake temps over 50, and its knocking with datalogit we can see your retard for 50deg plus to say -2 and this will cure any knocking (well at least attempt to) when intake temp (AIRTEMP under MONITOR) is over 50deg

You don't need to decrease all the figures at 2400/2800 only on the part of the map thats its knocking.

So its probably somewhere around row 8 or lower on the map window.

Make sure you make a backup of your maps and settings before you start fiddling.

You can write them down or someone with datalogit can copy them for you (i can).

[khunjeng]

great info...

I'm new to my PFC and only got a chance to drive it hard Monday and Tuesday...Normally the knock would be low 20s...but then I noticed it jump to 60...then today to 90 under some real hard load...

I retarted the timing -1 as suggested and really hammered it on the flat...went to 18 max on 1.05bar at 6900rpm...then in 4th up a hill starting from 2500rpm and flawed it under real load went to 22 max...so I real improvement.

I will have it re-tuned but waiting on a clutch...so this will do fine for the moment...

Thanks Paul.