New to ECU Modifacations

[benk]

At the moment I am trying to get my head around the program and how everything interact with each other,what each map/table is use for and changing a few things around ect. So at the moment I will be having a play around with the maps and setpoints in the program before I start on running it in the vehicle and once I get to that stage I will start by trying to run the new setup with the nvram and then move to the standard tune with the bigger injectors and 2 bar map sensor and then doing the turbo setup.

Just anothe quick question about the nvram. The laptop that I have is just a cheap a**** laptop and only has usb ports on it. Will the nvram work with the usb port?

[VL400]

The NVRAM will work with anything as thats just used as memory for the ECU. To allow the laptop to communicate with the ECU you will need a communication interface. The communication interface allows data logging and if an NVRAM is installed also tuning changes.

With a VN ECU and a USB only laptop you can use either an RS232 interface like this with a FTDI USB to serial adapter. Its important that the adapter works at 8192 baud, the FTDI brand is known to work at this data rate. Or you can use a USB comms board like this and connect directly over USB.

[benk]

will the maps out of the $5D code be able to transfer into the $12P code for the naturaly asperated side or are they a different setup?

Also, where can I find what the rev limiter is set at?

[Jayme]

the spark maps are the same up to 4800 rpm, above that the stock $5d adds 10 degrees advance per 1000rpm, youll have to do that bit yourself.
the VE map is different, if you look at it, $12p has more cells (65 and 75 kpa) and more RPM cells, (200rpm increments up to 2400rpm) you are best off whacking the $5d map into excel and averaging the cells around the blank ones to fill in the values. doing it that way wont be takign advantage of the extra loadpoints but it will replicate the same thing $5D does.

rev limit is funny in $12p. it is a soft touch limiter. youset the rpm here:
Map A: Rev Limit - Soft Fuel Cut Upper RPM Threshold - Above This Is Hard Fuel Cut

then you set how many rpm below that is the soft touch fuel cut (drop every 2nd fuel pulse)
then how many rpms below to do the spark advance reduction.

so what it ends up doing is hitting a cetain rpm, then reducing advance. if the revs keep risign it will cut every 2nd fuel pulse, then if it goes further it will cut all fuel.

[benk]

Thanks for that Jayme

I noticed that there were more cells in the $12P than the $5D but just wanted to make sure that the values in these cells mean the same in the $12P as in the $5D.

Is there a list somewere that has where to find all this sort of stuff mainly for the constants eg. what each tag means and what it adjusts. Like the rev limiter and base idle ect?

[Holden202T]

not really, more just a matter of having a play around or if you get lost, post it up here, eventually there will be threads covering everything as time goes on!

[benk]

No worries

I think I have most of the spark side worked out know except for where and how the base idle is set up?

Ok over to the fuel side, as far as I can work out the main maps that control the base fuel are the VE and A/F maps

[Holden202T]

ok we have these:

EST - Idle Spark Advance as a function of MAP ----- This is idle Spark Advance

VE - 20-100kPa Volumetric Efficiency (VE) as a function of MAP and RPM ----- This is the Main Fuel Table

Map A: A/F Ratio - 20-100kPa Air Fuel ratio vs RPM and MAP ----- This is the 'MAP A' Air fuel Ratio Table

so the idea is you shouldn't need to change the air fuel ratio table unless you have a motor with a big cam that needs a bit more fuel low in the revs etc, but what you have to do is use the numbers in the AFR table to get the VE table right.

so logging with a wideband you might see 13.8:1 at 60kpa 2000rpm for example ...... so this in the AFR table should be 14.7 so you go 13.8 / 14.7 = .939 ... so then you have a look at 60kpa 2000rpm in the VE table and say you have 75 in there so you go 75 x .939 = 70.43 so you update the ve table with that number and then hopefully if not perfect it should get the numbers alot closer in that area.

so how i do it is using scanner pro and the 12P definition i go for a drive and log data while i drive, then the data from the wideband histogram is pulled out and pasted into excel where it uses your current ve and afr tables, along with the wideband numbers to work out what the new numbers should be and it spits out a table of new values for the ve table.

so then you paste all the numbers in and go for another drive/log and see what happens..... hopefully the end result is that you can dial in your ve table to be much more suited to your new exhaust, or changed inlet or cam etc.

[benk]

I was wondering how you work out the VE. I take the "wideband" that you are talking about is a wide band O2 sensor correct?

When I want to set up a tune for power or for best fuel economy this is when I will need to adjust the A/F ratio because for more power you richen the fuel up a bit and for better fuel economy you lean it out or is this done somewhere else? I will have to set up the A/F ratio map for the boost as I want to run it a bit richer under boost so it's a bit easier on the motor.

I got hold of a complete VN with the same motor as what I am building yesterday for $300 to use a test vehicle to run some coustom tunes in it and it won't matter as much if I destroy the engine. Now all I need is to orginise all the hardware to start playing

[VL400]

Yeah wideband = wideband O2 sensor. Tuning a turbo engine you really will want to get hold of one, makes life much easier.

The advantage of EFI is you really only need one map for power and economy. Make the high load and boost areas what you want for power and the light load areas 14.7:1 and it will run like a stocker. A high and low spark map may be useful if your intending on running different octane fuels.