VN Commodore ECU update

[delcowizzid]

ill discuss the $5D as its the most used vn one.as long as you find the VE
"F29H: Volumetric Efficiency (VE) as a function of MAP and RPM"
and main spark advance "F1 SAMAIN: Main Spark Advance vs MAP and RPM"
then youre under way really these are the most used tables and are pretty much all that is needed to wake up the stock engine setup.the VE is the amount of air the engine injests at any given rpm and load point (map voltage/kpa) raising the number makes it richer. same with spark its another load based table with rpm vs map kpa 100kpa being full throttle area and 20kpa being deceleration area.
"F37: AE Temperature factor vs COOLDEGB" is the extra fuel added for acceleration enrichment much like the accelerator pump on a carby and is scaled against engine temp so at any temp on the left will add that amount of time to the injector Pulse Width. dont quote me on it being adding time to PW but it adds fuel thats all you need to know.
"F60: Open Loop A/F ratio vs RPM and MAP" is the commanded airfuel ratio anywhere that is 14.7 will be in closed loop when it reaches all the nessasery closed loop parameters.
KINJFLOW: Run A/F Param - Displacement/inj flow rate; (Litres/mGrams per s is the injector size pretty much its cylinder size devided by seconds per gram of injector flow.
ill add up more later but if you ask ill tell you what it is theres not really anywhere that has what every setting is these xdf's dont even have all the settings theres hundreds most are never needed anyway.

[delcowizzid]

allso search for thestig (exactly like that theres more than one) on http://www.justcommodores.com.au he did a lot of good tuning on his sc14 commodore theres heaps of them on there running the sc14 myself ide go like clint02 on here did turbo is much better and much easier to up the boost too.and the setup cost would be very similar

[mag]

Too late already have sc14 kit, but did not want big boost anyway, just a normal day drive vehicle. More as an engineering interest than outright performance project and do not want too many problems to keep it registered.

As matter of interest kit does not include 2 bar map any suggestions for supply in oz. Though I might get one from US if cheaper, see no reason why any brand cannot be used so long as output compatible with 808 ie 0-5 volts.

[delcowizzid]

my mate actually just soarced one from the US ill ask him for a website addy for the place he got it from.you could ask clint02 in his boosted vn wagon thread in members rides he will tell you where he got his from.this site has 2 places summit racing and gmpartsdirect links down the page a bit http://www.robietherobot.com/storm/mapsensor.htm just make sure you get a 2bar not 1 or 3.summit are allways good to deal with and send stuff rapidly.

[Holden202T]

ebay is another good option ....

[mag]

Now that I am contemplating DIY changes to my ecu, interested in the parameter that sets lock-up speed for o/d. By my speedo, my auto locks up 4th at 90kph, later models appear to be set lower around 75 so they run locked in an 80 zone. Real annoying as I have to run at 90 in a 80 zone. If I am reading tunerpro correctly for bin ATFYxxx, OUT TCC LOK TPS A is set 80kph and OUT TCC ULK TPS A is set 72kph meaning in simple terms o/d lockup should occur at 80 and release at 70, 10kph difference stops the auto hunting. If true why then does mine appear 10kph higher. Understand speed signal fron auto goes first to trip computer then to ecu but assume that trip computer does not modify this signal just passes it on.

If my reasoning all wrong then what sets loc/ulock speed for the o/d.

[delcowizzid]

if it says TPS its probably the throtle position for unlock/lock what xdf you using.you may find with the tcc locking slower it may end up useing more fuel as it adds load to the engine and takes away the torque multiplying effect of the torque converter.

[Holden202T]

well i know my situation is different (202 with T700 behind it and different diff ratio) but i have the same thing .... i think you will find if you get it to just over 80kms then cruise at that speed eventually it will lockup .... mine takes a good few seconds to lock and its probably partially the TPS as delcowizzid suggests .....

i've never found it to be dead accurate on the 80kms (too many other variables to take into account)

[mag]

Xdf 1227808. Appreciate your comment delcowizzid regarding potential disadvantages of lockup at 75/80kph but on level ground easy cruise at 80kph expect I would get better consumption and quieter engine if auto was locked up in 4th.

[delcowizzid]

you using the one off here called "DB 1227808" that wont work for the $5D bins give me 5 minutes and ill add a $5D up there so you can use it .when the TCC locks it makes the tune jump up a cell or 2 if going to slow .normally cruise is in 30 kpa area when the tcc locks going to slow it jumps upto 40kpa sometimes more which if you look the 40 and 50 kpa cells run less timing and more fuel .just the timing change alone costs fuel.the fuel isnt as much of an issue as its a closed loop area and the o2 sensor will keep it at 14.7:1 ratio but the timing does cost you a lot.