Newb question: Severe KR.

[Soopy]

Hey guys,

Cars a 2003 VY SS auto.
I've only just started experimenting with this sort of stuff and I'm here at the moment to clarify some stuff and perhaps get a better Idea of where to look.

I was given a base mafless tune by a bloke from a prominent Holden forum. Being a base tune I fully expected that tweaks would be needed.
I flashed my PCM and drove it easily untill it warmed up, everything is great with low load. I did how ever notice that the engine got up to temp allot quicker then usual, I'm not sure if this is an indicator of a lean tune or not (would make sense to me). I gave it two good WOT squirts and my V2 logged two massive KR spikes.

I'm just wondering which area's I should look in to rectify the issue, and what I should possibly log to determine where the problem area is.
I have a WBo2 installed currently, though I am waiting on a cable from TAquickness to log the AFR's directly with my V2.

As I say, complete newby here and I understand that this is a very fundamental issue, though I figure I've got to start somewhere.

Here is my logfile if you're interested: http://truestreetmachines.com/efi/LS1B_0006.efi

[swingtan]

Hey Soopy,
The basic steps for learning about tuning are these...


Log data.
Review logs.
Attempt to understand logged data.
Repeat steps 1 to 3 numerous times.
Start making small calculated changes to the stock tune.
Repeat steps 1 to 3


Moving forward, there are two main areas that you would be looking at for tuning.


Fuelling: How fuel is delivered, when it is delivered and how much is delivered.
Spark Timing: How much advance timing is needed for maximum efficiency.


You really can't get #2 right until you get #1 right.
You can't get #1 right until you get a WB O2 set up to log correctly and remove all knock retard that is occurring.

Once you get the serial cable, you should be right to log plenty of good data. However, you also need to add GM.DYNCYLAIR_DMA to your PID list so you can work on the spark table.

Simon.

[macca33]

Soopy, the tune itself looks like the VE table needs a fair bit of work and if you are not commanding enough fuel for the engine, it will knock. Once the VE table is dialled-in, you can start playing with timing. Yours being a bolt-on car will be good, as it won't take a lot of changes to get it right.

cheers

[Soopy]

Thanks guys, confirming what I had suspected. Will wait for the serial cable to arrive. (For ever waiting)

[Soopy]

Hrmm, seems even my standard tune isn't happy.

Bigger problems maybe...

[swingtan]

are you basing this just on KR? The std tune will always have too much spark advance in spots.

[Soopy]

Yeah just on KR, stock tune log file has 3.0KR at 80kpa, 5000rpm, 15degree's spark.

[macca33]

Post up the log Soop - I'd be keen to see it. As Swinger's says, the stock tune does ping its a-hole out, although running it on BP98 should mitigate most of that, I'd imagine.

cheers

[Soopy]

No worries, here is the link: http://truestreetmachines.com/efi/LS1B_0002.efi

Here's the tune while I'm at it:http://truestreetmachines.com/efi/Stock_boxtune.ctd

I've not touched it at all, save the gearbox (which is very nice to drive now I might add :) )

[macca33]

Wow, Holden certainly served up some crappy tunes - I thought he HSV stuff was ordinary!

As mentioned earlier, get your serial cable, do a few SD autoVE passes, then add some timing and you'll be set.

cheers

[Soopy]

Yeah, I'm thinking back to all the times it got some WOT on 35c+ days a couple years back... I'm very very lucky to still have the motor in the car.

Safe to say the car will sit in the drive until I'm satisfied the tune is at least safe now!
Also, I may change the servo I go to. I usually use BP98, but I'll give the Shell Optimax a run.

[Soopy]

Another question for you blokes. Sorry if I'm getting annoying :).

Just doing some reading, and decided to pay a little attention to my injector flow table. I've downloaded the spreadsheet TAQuickness provided and had a look. The stock tune is 100 country miles off what the spread sheet recomends.
Could this be partly the reason behind the KR I'm getting? (amongst other things).

I'm not going to change anything, simply trying to further my understanding.

[maudyZ28]

from what I hear with the injector tables use the one from your stock tune if you haven't changed the injectors. Apparently the HSV have a variable voltage fuel pump (hear this somewhere - dont have reference) and so IFT is not linear as the spreadsheet would indicate. Had this issue in my Camaro after putting in 28lb injectors from a HSV, needed to use a corvette fuel table with same injectors as HSV but that table is totally different due to fuel pump setup!

[Soopy]

Cheers for that Maudy.

Couple more Log files for anyone interested.
http://truestreetmachines.com/efi/decentrun.efi

http://truestreetmachines.com/efi/townrun.efi <----------- Registered lots of KR. The worst was 3.0.

[maudyZ28]

i'll try have a look at the logs when i'm home. I'm really wondering if the knock you are getting is like I was on the camaro, it's just ramdom peaks rather than the saw tooth repeated knock. This maybe due to the fact that the car will pull timing when MAf calculated air fluctuates more than a certain amount. I'll get back to you on this one :D

[Soopy]

It is kind of random.

[macca33]

Soop, I looked at the second log and whilst I've never logged am oem Holden tune, I don't think that is too bad - considering the oem tune isn't that flash to begin with. Some of it may be burst knock due to quick throttle transition, which does happen and some may even be false knock - who knows. You're running 98RON, so I wouldn't be too concerned. My old Senator, with the HSV 255kw tune pinged its ring out on 98RON petrol - so it isn't uncommon. Once you get your serial cable, you'll be able to dump the MAF, do an SD Auto VE and get the VE table right, then you can look at the timing tables.

cheers

[Soopy]

Yeah I was having a yack to Luis and he's helped me get my PID's set to check it right out. I

I reckon you're right though, still that little alarm is always concerning.