Has anyone got any good links to any Nissan ECU internal functionality/circuitry??? I can't find a thing. I have some awesome docs on Holden BCM and LS1 PCM. But I'm not going to post them here. PM if you want the links. Found some O2 controller schematics. Haven't had much of a look at them yet. Regards O2 Heater Controller >>> http://www.sergey89.ru/files/Nissan/WBO2/diy-wb_a.gif O2 Sensor Controller >>> http://www.sergey89.ru/files/Nissan/WBO2/diy-wb_b.gif http://www.sergey89.ru/files/Nissan/WBO2/diy-wb_c.gif
Read all the Nistune documentation. Explains it reasonably well. Few other documents getting around in regards to tuning nissan ecu's.
Yeah thanks, I've downloaded a bit already. >>> http://www.nistune.com/support-documentation-general.php Read somewhere all the Nissan ECU schematics are safe and sound under lock and key??? Regards
So whilst looking into Z32 Injector Reference Voltage Input (Current Sense???) I am reading RBDET ECU Pin #109 "Inverse Current Feedback", "Injector Power Supply", "Injector Power 12V Constant" etc Regards
You are having a good spray around the place trying to learn it seems. What others have said in relation to adjusting air fuel ratios to "tune" is correct, use a programmable after market ECU or a Nistune modified OEM ECU. Other piggyback options to affect MAF/temp sensor inputs etc to trick the ECU are old school, out of date and nowhere near as comprehensive as something like Nistune. What you suggested earlier about using discrete components (resistors) to modify the operation of a injector is not as silly as what some have said IMO. When nuting out what I wanted to do with my build I compared Nistune and AM ECU options, long story short the function that I thought was most lacking with Nistune was individual cylinder trim. At a very high level of tune power production can be matched and optimised across the cylinders. Differences in cylinder performance due to fuel/air/spark/temp could be adjusted, again this is at a fairly high level of tune and may be outside the realms of what is needed for a street car, but none the less I thought it would be good if a Nistuned car had this also. The technology to effect the operation of an energised coil like in an injector has been around for a long time, in this link you will see various methods of adjusting the operation and release of telephone exchange relays, http://www.dfrtelecoms.org.uk/relay.htm An idea I had was that with a set of in line modules (like a box of jets) you could "trim" fuel and timing across the cylinders. With a certain method of swapping known trims around I think you could work out the power balance but EGT's would probably be the go. (Some dynos can measure cylinder performance apparently.) As others have said this is not something you have a stab at unless you like doing rebuilds, it would be something that would take a bit of time to work out, but I think it would be possible. But at the end of the day if you want to tune at that level an aftermarket ECU with cylinder trim would be the go.
Hear what you're saying and agree would be an interesting 'exercise' but imo if you wanted to do this properly simply buy an aftermarket full ecu with this capability. Again you're trying to reinvent the wheel with an inferior wheel. Also to tune individual cylinders effectively you would need widebands for each cylinder afaik.
This is the same as an input hack, just on an ECU output, increasing fuel at a percentage across the entire fuel map would fix one problem and create others, would still preferably need to be Nistuned. Increasing fuel pressure to increase injector capacity then Nistuning is a different thing. But it has worked in the past on increased boost before things like Nistune were available. Just not as tidy IMO.
Yes widebands or EGT's (Exhaust Gas Temperature), cylinder pressure plug sensors, all very expensive and or engine dyno territory, and at that point a flash ECU would be the go for sure. BUT Reaching into the bag of old tuners tricks like pulling plugs immediately shutting down after a pull to read the plugs would work also. So rather than running cylinder 6 rich so that cylinder 2 does not run lean in the averaging out of AFR's from that bank. Thats an example using considered issues of differences in intake runners, position on fuel rail and block temperature front to back etc. Remember injectors can be easily +/- 5%, and on a straight 6 to run a ragged edge on AFR could mean one cylinder running rich in average to one cylinder running lean, let us hope it is not the one with compounding issues like intake runner or increased block temps at the rear. We essentialy do this on a VG but worse, AFR's are genrally only monitored from the "lean" bank and cross fingers on the other bank. Tuning is generally about sucking out the safety margin to gain the unused potential, running at 90% of potential with best quality consumer grade setup is what I have gone for as the cost of the extra 10% race car setup is a lot more than 10% in dollars unless you are happy to risk rebuild cost/effort. Using per cylinder noid style trim as I described above could be an easy cheap and effective way to venture into that extra 10% with safety and not having to invest in high end ECU's.
Hi, Thanks for the response. So with Naturally Aspirated. Could you switch between fuel pressure regulators, with fuel and vacuum solenoid valve(s) or something, to assist in switching between power and economy. I mean you can't just "get" more than the maximum regulated fuel pressure by changing ecu. http://www.tomei-p.co.jp/_2003web-catalogue/e135_fuel_regulator.html I wonder just how spastic your ECU would go if your switching anywhere near 120psi fuel, down to 30psi max and vice versa with OEM settings. Cheers
As soon as someone produces it and pays me a royalty. I think it would be worth doing as the popularity of OEM ECU's with things like Nistune, commanders etc is pretty popular these days.
That is a terrible idea from start to finish. I dont even think you know what you want to achieve. Playing with the AFR just for the sake of doing it perhaps?
Bah, if I ever have a go back. I try to do it in good humour. However, things to do right now, you guys can "boitch about the stoich". Regards.
Yep you and I both know that. BUT AFAIK its the only way to do what he said good or bad. Never catch me doing it like that.
So irrespective of Injector Reactance vs Fuel Pressure Ie >>> If we start switching fuel mixtures. We are also going to have to (or most likely) switch O2 feedback. So provided you account for O2. How much can you cut/add fuel mixture until it will start to effect other engine parameters??? Are there not a few conditional fuel maps on OE ECU???
Drifter, the problem you will have, if you start running higher fuel pressures, you will have more fuel going into the combustion chamber, which will require more air to maintain air fuel ratios. On a turbo motor this is easy, turn up boost. On an NA engine, not so easy.
To be honest I would only really be tweaking it one way or the other. But I could see many problems approaching here. I think some pressure regulators have specified slope. Ie higher or lower rate of increase in pressure regulation in relation to vacuum.
