VN Commodore ECU update

[delcowizzid]

no bin wont have enough cells with the 2.5bar ide just get a 2 bar like everyone else does its good for more than the sc14 will ever put out and doesnt need as many cells in the bin.you could use a honda 1.5 bar would be plenty as well.but all of the tunes around are set for 2bar sensors so its the normal and best way to go.standard injectors on 6psi will most likely start to rattle the engine due to knock from lean fueling you could maybe get away with 24lb at the least but 30lb red tops or 36lb supercharged V6 are best and what most people run.the 2bar$5d will fit on the 27C128 like the sv3800 will.when using the bigger chips you need to adjust the offset or just stack the bin in tunerpro which saves working out offsets but they arnt to hard to figure out.did you buy a willem programmer thats what i use has done hundreds of burns and still going strong.

[mag]

delcowizzard, yes bought willem based programmer. have removed eprom from spare ecu and will soon have installed socket ready for eprom with sv3800 tune. also have acquired laptop, loaded winaldl and manufactured aldl cable, as first step into world of tuning. TunerPro in real time programming the ultimate goal. but some way off. hope to use spare ecu and winaldl as test-bed to evaluate home-made 2 bar map. if all goes well would be low cost $30 alternative to current after market units. anyway want to play around with ecu test-bench to satisfy my curiosity.

[mag]

took a while to get burner running from laptop. laptop serial port address was not burner default, desktop was ok. problem now is sample eprom has some bits set and i dont have eraser, oh well was going to use 27sf512 chip eventually anyway. got winaldl up and running with car in the garage. bit disconcerting when service lamp began to flash but once i worked out what was happening made sense, after all it is connected to the data out line from the ecu. a couple of questions regarding real time tuning, other than saving time swapping out and burning eeproms, is on the run manipulation of the ecu parameters worthwhile unless applied to say a track car on race day. anyway if you fit a ZIP socket to the ecu, eeprom changes should not be a big hassle.

[Jayme]

when you are trying to get fueling and spark table right, youll soon get sick of burning a chip everytime you want to make a little change. I would get used to tuning with your burner first though and when you get sick of burning chips all the time, then get a realtime board. the 2nd advantage is that as a consequence of installing the serial coms board, you get 8192 baud which gives you about 10 frames of data per second. much more useful than old 160 baud.

[Holden202T]

yeah i have to agree, especially after tuning an engine that there is not any standard files out there to start from .... it makes tuning a hell of alot quicker if you can do it on the run ...

as far as the 160 v's 8192 ... its not comparable basically, 8192 is useful for a WOT run and 160 is a waste of time .....

having said that i agree with above that you should fully get your head around burning chips etc and changing stuff in the tune before going to realtime, will make that next step a bit less overwhelming!!

[mag]

thanks for all the assistance everyone. your comments/suggestions much appreciated. hope to have sv3800 tune in 27sf512 end of next week allowing for delivery of eeprom and install of socket in memcal. meanwhile i can play around with winalaldl.

on real time tuning, just to understand the process, you drive the car around with a known tune and log the parameters. then assess the results and make adjustments. now the hard part, adjust what, which way. the adjustments i assume is the experience bit. any hints as to what to aim for when tuning the tune.

[antus]

The VE (volumetric efficiency) table is the main thing you want to get the right mixture, and the spark advance table is the main one to get the most power before you engine starts pinging. I havnt used it but delco wizzid has recommended winaldl as it will monitor your mixtures and suggest the changes to the VE table. However I should go back a step and explain how the ecu calculates the fuel.

The ecu knows how many cylinders you have, and the capacity of your engine. From this it knows how much air will fit in a cylinder. Its job is to open the injector for long enough to deliver enough fuel to get the right mixture (time and fuel pressure being factors that define how much fuel comes out). Then other factors adjust how dense the air is - the temperature of the air being the main one. There are tables to define how much difference the temperature and other factors make, but these are pretty static. Nothing you really need to bother changing there for engine changes.

Then comes the volumetric efficiency. This is a measure of how efficiently the volume of air the cylinder can fit can get filled. For example, my 2L 4 clylinder has 250cc cylinders. At different engine speed and load points, a different a different amount of air makes it in. In pretty much no case its 100% of the capacity, and can be as low as 40%. This makes a huge difference to the amount of fuel required to get the right mixture, and the propertys change quite a lot from engine to engine, different intakes, cam etc etc.. This is why this is the most critical table.

Back to winaldl. It'll monitor your engines loading, rpm, and the amount of oxygen left over in the exhaust. You can drive around for a while and it'll tell you how far out your VE table is from reality. You go an update that table in real time, or reburn a chip and try again.

Spark can be advanced a little more depending on the octane rating of your fuel, but I know less about this and this is where you can do engine damage so I would just keep the timings from the sv3800 tune. Others here may be able to offer more advice on this part of subject. Generally speaking if you wanted to 95 octane full time you could advance it so much, and 98 octane a little more, meaning you get more power from each stroke of the engine, to the point of going to far and igniting the fuel while the engine is still compressing, so that the piston has to fight the explosion.

Sorry if thats too much information, dont want to insult, just got on a roll and wanted to explain the main bits as far as i understand them.

[Holden202T]

probably somewhere that would be a good spot for you to start is with winaldl and the blm's ... use winaldl to log the blm's into the table and then you can use that to tweak your VE table ....

now its been ALONG time since i used winaldl but i think its the same as most other programs ... so you'll get a heap of numbers in the cells .... say mostly 128 numbers these mean the air/fuel mixture at that point in the VE table is right, but say at 2000rpm, 60kpa you get a number of 130 .... this means the engine is lean in that load point and the computer is adding fuel to get it right..... likewise if you have a number of 125 that means its too rich and the computer is taking fuel out to get it right.....

so what i find is a good way to do it, make up a spreadsheet that you can pump all these cell results into and then from that have a calculation create results of how much percentage change it is from 128 ..... so say one answer for 2000rpm, 60kpa comes back at 0.98 ... so then you go into your VE table in tunerpro, select that load point and then in the toll bar change it to multipy then put .98 into the field and hit enter and it should offset the 2000rpm/60kpa load point to 98% of what it was ....

so basically just do that for all the ones that arn't on 128 and then you should be pretty close to a decent tune for most of the map .....

[delcowizzid]

one thing to watch out for is when logging a stock tune you will have diagnostic spark at any rpm below 2000rpm as its set to lock timing at 10 degrees when you have the aldl bridged untill above 2000rpm.this makes the blm's look rich below 2000rpm cause of the low timing so the first step really is to burn a tune with the diagnostic rpm in the top window of tunerpro too 0000rpm and then get logging.

[mag]

All information greatfully recieved. lot to learn and happy to listern. I take it that adjusting values based on data from winaldl etc to suit a particular engine is where the benefit of a custom tune is noticed. is the difference likely to be significant in both values and seat of pants after changing values to get the ideal 128 and timing changes.

I'm more a hardware than software guy, although have developed both hardware and software for a programmable bike ignition that adjusts timing relative to rpm. hense my interest in developing 2 bar map sensor and 808 test bed.

would be interested in anyones thoughts on bin to suit sc14 installation biased in favour of passing NSW RTA emission test. once mods approved will then change to more appropriate bin for performance. trying not to have to repeat emissions test and/or replace cat etc. anyone had any experience with RTA emission test, what driving modes etc and if there is a requirement for fuel vapour control.

delcowizzid found KDIGRPM set at 2000 rpm as you predicted.