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2004 Sentra will be the same ECU but I am yet to see a ROM posted for that car although I would be very interested to see what differences there are - a SpecV ROM would be even better. The electronic throttle can easily follow the accelerator pedal movement opening or closing - it is a programmed ho...

Hi fenugreg, The Sentra ECUs are the same for the same model years. The processor is a SH7055 which has internal 512K memory. I am flashing at a very low level (AUD) mode hence the direct connections to the chip. What year is your Sentra? Can you use NDS2 to log all engine parameters? If so, you may...

Hi Tom and any others watching this, On the issue of Cam Advance hunting, it starts off O.K if you clear self-learn but reverts to hunting after a short time. It has always done this and it is not a faulty sensor. I think it is conserving the limited processor time for more important tasks like chec...

Part 3.... Out in the cold If you ever thought it impossible that a manufacturer would run 50 degrees advance at 1600rpm then look carefully at the log. This is the addition of a cold map on top of the low knock map - you can see in the lower graph window how the total advance drops away as the engi...

On to the tuning (or What was Nissan thinking???) Part 2 Note on the difference graph that some significant timing has been pulled at low rpm and bucket loads added elsewhere. The dealerships often retard the base timing to 14 or even 13 degrees to solve spot knocking issues because of a whacked out...

On to ignition timing....Part 1 There is no single definitive map for ignition timing. The easiest and safest way to alter timing is to edit the "low knock advance" map. There are 3 identical consecutive maps in this ROM which are the low knock advance maps. I keep these identical when edi...

Australia has 91, 95 or 98 octane fuel fairly widely available and a bit of E85 in very few places.
I will be covering ignition timing next so this is a relevant question. I run 91 octane usually. There are some surprises in the stock timing but that story is coming up....

And a 3D view that shows the dramatic EGR region on the stock map alongside the modded map.
You really have to "interpolate" the map values to understand what the actual outcome is going to be.
For that I use a spreadsheet (see the 16x16 map pics)

And here is what the original and modified cam maps values look like (in decimal) and these are found at address 6CB5 in my particular ROM. I use WinOLS Demo software only as an aid to find maps, manipulate and visualise the data in text, 2D or 3D form. It is no use for its more advanced features in...

So onto the tuned map.... Be warned - Any change to the cam timing has a large impact on fuel and ignition timing requirements. What's different? Advance starts climbing from a lighter load point across the rpm range - better light throttle response. Over-advance (EGR) reduced to just enough to crui...