With all these companies charging us over $500 bucks for a re-flash I was wondering if anybody has the computer software to tune their own car.

I am going to buy a wideband and try to tune my own car. I heard the factory ECU for the Z is really hard to tune.

So if anybody has any input let me know.

 

I'll admit that I don't know much about it. But I'm pretty sure this is a terrible idea. The potential for damage is way higher than $500, and you can't insure yourself.

 

The DIY tuning is a great idea. I don't get the rampant "don't do it or you'll blow something up" attitude on this site. Seems like everybody is so willing to just open up the wallet and pay, it's scary.

This being said, to the OP, the devil's in the details. You will not only need a wideband, you should probably get an EGT gauge and then the hard part, EM. Yes, you can tune the stock ECU but the hard part is getting access to the ROM and figuring out how it works. I'm talking about basically disassembling the code and making sense of it. Unless you're a seasoned assembly programmer and you have indepth knowledge of automotive systems, it will be next to impossible. First thing you have to do is figure out what processor architecture you're dealing with. It's either H8 Hitachi microprocessor or Nissan moved to Motorola architecture. After that, figure how to get the ROM off it. After that, you'll need a disassembler to figure out the code. Once you know what is what, you'll need to flash it back on. Not as easy as it seems. I know it sounds complicated but guys already done this on Subaru platform....basically by hacking the ECU. The end results have been extraordinary. Good luck.

 

Would it not be easier to simply purchase a utec?...
$800 vs "all that stuff posted above"?

 

Absolutely But from what the OP posted, sounds like he does not want to do that...or at least that's what I got out of it.

 

If you go the UTEC route, you might wanna check out the subby forums also as most of those guys tune their own UTECs and are very open about UTEC tricks & tips.

 

Thanks for the info guys, exactly what I wanted to know. I was just thinking off cutting out the middle man. Sounds like I should get a UTEC or Pro-FC. Thanks guys.

 

i was just thinking about this last night. i used to do assembly language programming. I wonder if there is a market for that, especially with the new gtr coming out with a bunch of restrictions

 

this tread has been very informative. thanks guys

 

Yaya!! if any one has software that gives you full access to the all the hundreds maps for under 500 bucks, and is in a language other than Hex, please let me know. Cobbs been working on it for a year and a half, and there just now getting ready to release it but its 6-7 hundred.

 

dang...

 

Well, Cobb has all kinds of different requirements that DIY people do not have to worry about initially. To give you an example, I'm a software engineer. If I can get access to the ROM, I can run it through a disassembler (IDA Pro) and try to find an entry point to the ROM. I don't have to worry about building a nice, fool proof device for map delivery and pretty output.

I admit that I have not looked at assembly code for along time but if I had to, I can always review and try to make sense of things once I see some disassembled code. I've done this with my WRX ECU when I owned the car. Although most of the work was already done, I had a good look at how things are arranged and I managed to find extra options in the code for things like radiator fan thresholds and other fueling options like RPM enrichment compensations. If you know enougha bout assembly, it's pretty easy to spot maps in the code and the memory locations are pretty obvious. Honestly, based on what I have seen, getting the ROM out and making sense of it is not the hard part. It's getting it back on the ECU is where things are usually a major pain since writing is usually protected by the manufacturer with various routines and protocols that if not done perfectly, will not allow the ROM to be overwritten.

Right now, I don't even know for sure what microprocessor is used in the 350Z ECU. Since 04+ 350Zs support J2534 standard, I assume that those ECUs are based on a very different architecture than my 03. That is probably good/bad news for me. It means 03s are probably easier to hack since as they are probably a lot less complicated but the bad news is that it's a mistery protocol and how to talk to it. 04+ ECUs support the standard protocol but the ECUs are probably a lot more complex.

 

no one makes a DIY reflash software for this, or any other CAN BUS network car I've ever seen.

if you want to buy this software, it's a simple procedure - give Technosquare a call, plunk down your ~$8000 and you'll be able to do all the reflashes you want (not sure if that pricing is current now, but as I recall that's about what it ran when I asked a few years ago).

The rampant "its a bad idea" mentality is well deserved I think - if you notice, this site does not have the most technically minded population out there - much less than many other "big" forums out there, for a variety of reasons.