??? 11/15/06 22:10 Read: times |
#128050 - Two different beasts! Responding to: ???'s previous message |
The Kawasaki GPz1100 unit was fuel only and was made by JECS. This company liked using hitachi (motorola) 6801 style cpus. Their designs were also reminiscent of 80's Bosch designs where they used a single slope a/d chip. The analog was usually all at 8V. You can get the code out of these cpus, but it is far from easy - you have to make a board with external eprom that boots the cpu up from the eprom, then reads the on chip rom and outputs it to the serial port. There is also the japanese variations of this chip as I found in my 83 Mitsubishi Cordia ECU - the same style cpu but it had another timer block - this was figured by deduction. Luckily for me, it was exactly the same register configuration and operation as the first timer. In the cordia box, rather than the single slope a/d which ties up the input capture they use a toshiba tc5091 ic (like in the rx7 box) which turns out to be a adc0819 a/d converter. At a guess, I'd say the rx7 has a motorola style cpu - you'd have to reverse engineer the circuit to get a better idea. Look for where the crystal connects, the crystal frequency, the port and power pin layout. The Honda box has a lot of logic chips in it - this is usually for the 'limp home' mode where if the cpu dies it pulses the injectors and selects the base ignition timing. As for the complexity of the Kawasaki box - its injection system was similar to anything else of the time. It factors in IAT, batt voltage, throttle position, atmospheric pressure and rpm to derive the fuelling. Initially, the 8051 is not really suited to fuel injection duties - mainly due to the timers. The 6801 had input capture/compare that made it more suitable for these tasks - probably since it was targetted to this market. It was only on the later 8051 variants (Intel FA,B,C) that had specific timer hardware that suited fuel injection duties. The 90's Hyundai cars had a Bosch copy box that used a siemens 80c517 cpu - mind you, these have a lot more code in them than say, the cordia and kawasaki boxes (4k). Again, as to why you would want to reverse engineer the old honda box is beyond me - the cx500t was not a particularly popular bike - nor very powerful. The turbos would be dead by now one would think. Personally I would try to get the fuelling curves and use these as a base for an 'off the shelf ecu'. Any modifications to the engine and you really need to dyno the engine to tweak it. Besides, they weren't exactly leading edge engines in performance in their day!! Similar sentiments eith the RX7. The first thing you'd do is to modify the engine for more power - so using an aftermarket ECU is the go. There's plenty of units for the rotary engines since they are very popular for modifications. Over here one unit that is popular is the Wolf3d as it can control the rotary specific ignition. As to why I reverse engineered the ecus I did - I wanted to learn about fuel injection. I also learnt a lot about failure strategies. I did have the idea of porting the codia code over to a hc11 cpu since they are a later version of the old 6801 but I lost interest! Again, since there are a few ecu designs kicking around the web that have better performance and some nice windows software to tune them. |
Topic | Author | Date |
Help in reverse-engineering an old 8051-based ECU? | 01/01/70 00:00 | |
Toyota boxes perhaps? | 01/01/70 00:00 | |
Not Toyotal, although that's already been "hacked" | 01/01/70 00:00 | |
Are the mazda & honda the same? | 01/01/70 00:00 | |
Getting there... | 01/01/70 00:00 | |
Two different beasts! | 01/01/70 00:00 | |
I could kick myself. | 01/01/70 00:00 | |
Mazda vs Kawasaki box | 01/01/70 00:00 | |
Yep, 680x chip. | 01/01/70 00:00 | |
How to dump 6801![]() | 01/01/70 00:00 | |
Have you verified the fixed connections? | 01/01/70 00:00 | |
Not yet... | 01/01/70 00:00 | |
ignore this double post, plz. | 01/01/70 00:00 | |
email address? | 01/01/70 00:00 | |
Ping me here... | 01/01/70 00:00 |