I did a parts search to see what the going rate was for a FED or CALI spec ECU. They ranged from under $100 to around $400.
However, they also listed SEVERAL(around 12!) different configurations of ECUS.

Basically,

Both FED-Spec and CALI-Spec. have:
----------
Automatic
--w/ traction control
--w/o traction control
--w/ 16" rims
--w/ 17" rims
Manual
--w/ 16" rims
--w/ 17" rims

The ECUs with different rim sizes are most likely the same, but with different programming for speed limiters. Multiple ECUs is just another obstacle to deter aftermarket companies, along with the fact that they are only good for 2-years of Maxima production.

I'm still looking into finding a cheap ECU, pulling off the ROM chips(hopefully NOT RAM!), socketing the board, and trying to decipher the programming to see if it can be modified. I have EVERYTHING necessary hardware wise(except an ECU), but "breaking the code" is another story. It might take 10yrs, but who knows.

Also, anyone with 16" rims stock, MIGHT be able to swap to an ECU programmed with 17" rims to have the higher speed limiter.

 

Sounds cool man, keep us posted on the progress.

 

I would think anything under $400 would be a good price. $100 sounds great. Were are you getting your information on these prices?

 

http://www.car-part.com

$100-$400 is just for a donor ECU, for people who don't want to modify their stock one. I myself, won't modify my stock ECU, but keep it for a spare or for when I sell the car.

 

Nice info!

 

thanks for the info!

 

Check out this site... I believe this is what Nissan might have used on the Maxima's ECU. It says this was used on the MY 2000 Sentra.
http://www.dspaceinc.com/en/Products/PCGS.htm

Dave Z

 

There is already technology out there to do what you want - the unichip piggypack. Everything you want can be done. You will simply need a tuner to do it.

Even if you were able to "crack" the ecu - you'd still have to reprogram the fuel/timing etc. You'd still have to have a tuner to do that.

 

I upgraded my wheels from 15" to 17", does that mean I need to upgrade my ECU? Thanks Ice,

J-Rod

 

Mostly for personal knowledge. One day(hopefully when I'm around 40 or so), I would like to own my own "performance shop" like Lingenfelter/Roush/etc.. to enhance many types of vehicles. Also, to see if it's plausible or realistic or if I'd be better off buying/designing a stand alone unit that is laptop programmable such as an Electromotive TEC-II. I've done some research into OBD-II and I believe we could use it to enhance the performance of ANY vehicle, but you need to be able to control/modify the ECU for any real gain in performace without drastically affecting driveabilty and reliability.

I'm not up-to-date on the "unichip piggyback", so I don't know how it works. I do have a problem with MOST add-on chips that "trick" or modify signals that the ECU is receiving. I believe they're tempermental and limited in what they can do before the ECU revolts. Also, it would be a one time deal and wouldn't adapt as modifications occur without paying $1K+ on dyno tuning sessions. You can modify fuel/timing maps and monitor the effects in realtime using the OBD-II system already on your car, so you don't necessarily need dyno tunning, buy it would would speed up the process.

Honestly, I have no idea what will happen or if it's possible. It's just an idea I've been throwing around and I'd like to see what could happen. Basically, I'm a little bored at work and I need something to keep me awake. Thanks Maxima.org!

 

Wow, you knwo much more about this than i do. but if you are planning on opening your own performance shop a few years down the road, couldn't you write off the cost of the stock ecu's as training or something for taxes? make it cheaper and easier... and as for the piggybacking, from what i've heard all the chip companies make nothing that benefits a 5th gen max, from all i've heard gains are exactly 0hp and 0tq...

now, if someone could hack in and set up a program to change fuel and timing and what not that would be a huge help. maybe not so much for those of us without laptops, but it could include several automatic plots that help too...

 

The only benefit would be a higher speed limiter(NOT rev-limiter).

Do you really need the extra 23mph or so on the top-end?

 

I'm interested in your work in this area. Have you thought about speaking to the guy who wrote the OBD-II software package? Perhaps he could shed some light on a few things.

 

Actually, I was going to buy the software anyways. I'll keep you posted once I get started and if any progress is made.

 

That is EXACTLY what the unichip does. It works on any OBDII vehicle as I understand it. The problem is how do you know what changes to fuel and timing will yield a positive result?

Only one way, make the changes and then test it on the dyno.

 

I guess my point is how can you do it in a vacuum? Lets say you make changes - how do you measure the value of those changes?

I don't have your apparent understanding of the tuning process but how can you know whether the changes you have made have provided any benefit. Sure you can monitor variables but you won't know power output/curves. If you want to just be able to make those changes, could you learn how to tune with the unichip?



You are right, each time you tune the unichip it's gonna cost you. In fact, that's one of the reasons I haven't done it. But, no programming is going to adapt as changes are made. Whatever method is used, if you want to optimize the change, you have to re-tune.

I'd be real interested in knowing what you think about the unichip and how it works. Seems like you have the equipment/knowledge to experiment with changes using that device rather than trying to reinvent the wheel. Heck, you could be the pioneer for us!

 

I just went from stock 16s to the OEM 17s. I know that the speedometer error is there (although admittedly small); is it possible to change THIS in the ECU without a total swap?

If it can be reprogrammed, who does it? The local Nissan dealer says they cannot.

Jack

 

Hey I DEFINITELY don't claim to be an expert in the "tuning process". I've only had about a years worth of "experience", more like playing around, on a Senior project in college with a fuel injected CBR600 and a TEC-II and about 7-months designing software for jet-engine ECUs. Basically, with OBD-II you can monitor LOAD which is a relative measurement of power and you can plot load through several runs to get a typical trend of the "power" curve. Then you adjust/modify whatever and try to repeat the same runs to see if there was an improvement or not. Also, you can play with the A/F ratio and timing by adjusting points and LIMITS in which the ECU can run the engine. A lot of this can be done on a stand alone unit such by switching between open-loop, adjust a few things, then switch back to closed-loop and monitor the engine for a change towards a stochiometric air factor. However, the stock ECU does this at start-up, but IF possible, maybe you can do this in realtime after startup. Again I have NO idea what is or if anything is possible. Apparently, companies such as JWT have tried and failed, so I don't know if any gain performance wise is possible, just knowledge wise.

Software can be ADAPTIVE both statically(reprogrammed for each change) and dynamically(optimizes for current conditions by calculating optimal fuel and timing). It's all dependent on how the programmer designs it. I'm definitely not able to redesign the stock ECU software, but it SHOULD be possible to adjust the stock limits. All ECUs are factory programmed according to specifications some engine dyno guy determined from test cell experimentation and feedback from field tests. Then some hardware/software engineers form the logic design, which is then implemented in hardware(ECU board/sensors/actuators) and software. The software programmers take the logic design and implement it as close as possible to his interpetations, but there is ALWAYS room for fine tunning. Each car and the environment they operate is different, so the program is built to be flexible within limits. My hypothesis is that as you add an intake, exhaust, SC, NOS, etc.. you are reaching or exceeding the limits of a stock motors air pumping capacity, so therefore the ECUs limits NEED to be adjusted to operate properly. People throw around the A/F and timing map terms a lot. To my knowledge, these maps are points in a table that the ECU uses to calculate the proper fuel/timing for that specific load/RPM. If you have an eight-by-eight table(map) and you are NOT exactly on the point in the table, the ECU "interpolates"(calculates) between the two nearest points. The 8x8 table points are for a stock engine and typical operating conditions, so if performance modifications are made, the ECUs operating parameters change and it moves to a different "path" on the map. Again, my hypothesis is that the stock map can handle changes do to the flexibility of the stock ECUs need to handle different cars in different environments(temperature/atmospheric pressure/humidity/etc..), but as you near or exceed the stock limits, the ECU is using points that were never really expected to be encountered or dummy values that are equal to the max values. Sorry for the long response, but I had a few Mountain Dews for breakfast!