1slow370

First off cut me some slack the only time i can get on here is after 12 hours of work at 3am which leads to me confusing myself sometimes. I'll try to be clearer sorry.

What I mean by saying that the hardware on these things is simpler than a computer is that instead of having a BIOS running the hardware and an OS performing various tasks, your ecm only has one level of system. So it can't run say Mac OsX, Linux, and Windows on the same computer like you can with a PC. There is no OS, just the code stored on the Eprom chip.

Because the system in an ecu is so simple, you can't simply "replace it with your own software."

The hardware in the box limits what you can do because often times there are separate chips in the ecu that do specific jobs that cannot be re-flashed so you actually can only change some of the code and have to live with what nissan put on the rest. Also the individual components on the boards limit what can be done. If you have a narrow band O2 sensor that is putting out extremely low voltages around a volt at most, and it sends that voltage to an analog to digital freq. gen. so that the data can be processed by the chip, you can't hook up a 5 volt wideband and expect to be able to program the chip to accept it. You'll just end up burning out the parts of the board that process the signal from the sensor.

As far as MAP and MAF sensors go I only have experience with the commonly used GM ones. MAP sensors come in two flavors analog and square wave. If Nissan uses square wave sensors, you would have to reprogram that whole area of the code on the ecu and any area that uses it, to accept a different frequency range used by a larger sensor, unless they all use the same frequency range in which case you could treat them like analog sensors. Analog sensors commonly used by GM are all 5volts and work on less voltage=less pressure, so a 1BAR map would have the table set to read vacuum in the low voltages and atmospheric at 5 volts. For a 2BAR MAP you would be squeezing 15 more PSI into the same 5 volts so when the ecu see's 5 volts It would normally think you were at atmospheric when you actually have pressure. With analog sensors you put greater values in all the tables that reference it to trick it into working. So on a VE table when it's at say -7 psi you would actually be putting in a value somewhere near 90% efficiency instead of the 50% it would normally have because the pressure is greater. But when you do this you are changing the accuracy of the ecu because on a table that has only like 15 values on it's axis you are now only using 7 to cover the pressure range that previously had all 15 slots. On the other hand, if the car uses a square wave sensor there may be another controller inside the ecu that takes that frequency and changes it into another frequency for processing so if you switch out sensors and are now using a larger range, the ecu won't be able to handle sensor frequencies beyond what the first converter can handle, and you won't be able to re-flash that chip to change it's range of frequencies so it will never be able to accept boost. All of this maters if you want to get rid of troublesome, restrictive and delicate MAF sensors and run speed density to avoid going super rich when the blow off opens.

You run into issues like that with every sensor and every part on the car, so in order for a company like uprev to write the code in the ecu to do different things than it normally does you can't just tell it to do it with software. You have to completely tear apart the whole car, figure out exactly what happens between each and every sensor and the ecu, and figure out at that point what can and can't be done. The only people with that kind of R&D time into making a reflash is NISSAN. They designed it so they know exactly what it can and can't do, and fat chance of them ever telling anyone anything. That is why certain companies focus on certain makes of car and why re-flashes cost so damn much. You have to invest a huge amount of time into figuring out even the smallest parts of the code in the ecu, so it makes sense to focus on cars that use similar codes so you save R&D time. Uprev won't be able to do most of things I stated because of the limitations of the hardware and the COLOSSAL amount of time it would take to figure it all out without having Nissan's design information. Now if someone from NISSAN could graciously violate their NDA and leak the design information of the ecu and it's code I have no doubt that Uprev would be able to do wonderous new things. Since it takes a huge amount of time, in 5 years from now there will be some wicked stuff for us, just like there is for the 03-06 350z, unless everyone with a 370 wants to blow cash like they own a GTR.

This is why standalones and piggybacks sell. The companies that make them design them to be able to support whatever components they want and the hard part for them is getting it to work with other controllers found elsewhere on the vehicle like the ABS and dash. So the farther you want to vary your setup from stock, the farther you need to modify the ecu. Is a standalone the best option for every one? Hell no, but if your going to be doing FI and want to be as safe as possible and be able to account for every little thing the engine does without just putting a bigger number in the table to half @$$ it, a stand alone is your best option right now. Sure you can get re-flash utilities to work boost applications, just not as well as a proper standalone could. They probably will both make the same peak power because you can just screw with the re-flash until the advance and the fuel are where they need to be at that one point in time, but for efficiency, reliability, and driveability it won't match the standalone unless it can do most of the things i asked for. I'm not trying to bash re-flashing it works wonders for some setups but not for all. Know that before you buy.

Edit: I think this ones a less confusing post so I might delete my last one unless I get lazy.

Edit: Oh and for the record UTEC's are total garbage that shows that not all piggybacks are created equal.