Ok, dispite some initial excitement and quick learning I have now realised that to advance is going to take some considerable effort and time. I have done countless updates of the PCM in the last few weeks and almost started again today as I had a weird hesitation from 2000-3500RPM.
I tried a GTS tune which didnt help any and compared the maps I had done, surprisingly (or otherwise) the spark and ve tables were close, so I thought the issue must be elsewhere. Sure enough after some suggested logging I captured the culprit, BKR or Burst Knock Retard. This little blighter, which is especially hard on SD tuned vehicles, retards timing based on a preventative algorythm. It basically checks for delta airflow values which exceed a certain amount and retards the ignition based on a table. Suffice to say the table and airflow values have now changed. The stock Holden GTS has more agressive settings, while I have gone even more aggressive.
I have also learnt to check for knock sensor voltage while also monitoring knock. This allows you to differentiate between "false" knock, and real knock, as the sensor will be jumping around when real knock occurs and be fairly quiet when false knock is about. Of course false knock can be ignored except for the fact that it can mess with your timing. A partial solution is to tweak the "knock retard recovery rate" table to recover quickly. Knock being a potentially ruinous situation always requires care.. as does running too lean. (Hence a wideband is seen as fairly essential for tuning).
I have therefore ordered an O2 sensor socket so that I can pull the old one out and make up a harness. This will allow me to transfer the sensor to a friends car rather than a permanent fixture in mine. Hopefully I can get the blighter out. I spent a few minutes with a cresent the other day hefting on the drivers side O2 to no avail. I think a large lever is called for.
Im starting to consider what to do once things are tuned right. This isnt likely to be any time soon. Perhaps early next year I can consider things to be "ballpark". Id then like to do at least a cam swap, perhaps heads and intake. In fact I just bid on an LS6 intake and injectors in Oz. Would be a good upgrade from my current LS1 and 26lb injectors at the right price.
Im considering an SDPC custom cam, which is in effect an off the shelf Crane jobby. Specs are 220/224 and 0.551 lift. Or 0.583 with 1.8 rockers. Should be good for a 12 sec 1/4 or 11's with any luck. That should do me for a while. Heads and intake can wait till I go for a 402 stroker. (Which isnt planned until the engine wears out or I kill it, whatever comes first!).
So in summary, lots to learn and lots of time required to learn, but as long as I pick something new up each day we are on the right track. New 0-60 times to come soon.
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