ND, What do I do? So if I say try vince's idea of dropping the MAF resistence 5% and run 105 race gas then what? Would you try guessing at a chip map? Can I use an innovate wide band in place of one of my stock 02's and send you data at different rpms to see the A/F ratio? Can I also splice my ecu into the wide band so my ecus see the 02's properly or do I need to knock another hole for the wideband 02? I thought that our ecu's use 02 for idle and maybe part throttle but default to an rom ecu map at wot?
Here's a 348 Spider OEM spark advance table -------------------------------------------------------------------------------- 6BAC[]: = f( Engine RPM ) *spark advance curve NOTE: the TPS chip bumps up each OEM value in this table +6 starting at 6BBE RPMS:800...920..1280..1520..1720..1840..2000..2520 ..3520..4000..4520..5000..5520..6000..6520..7240 VALS: 21....22....25......28.....2A.....2D.....31.....36 ......3D.....3F.....42......42.....42....41......3 F....43
Get your A/F curve as close as you can with your MAF resistance adjustments. If you need your A/F curve tweaked after that, then I can do that on the chips. I do not know what 105 octane gives us. Obviously it gives us more room to advance our spark timing, but I can't tell you "how much." Yes, the Innovate replaces an O2 sensor. It sends two signals. One signal goes to a display that you can wire into your driver's cockpit. The other signal you hardwire in to your O2 harness. That's going to greatly aid with getting a good A/F curve...but it's not going to help us figure out how far we can advance our spark timing. What I can show you are things like factory stock ignition timing curves on the chips...and aftermarket timing curves...and the curves that I've used on my own 348 so far while using 93 octane. One post above begins that journey. Now, "how far" we can push this thing is an open question. You know what will happen if we go too far.
OK, a caveat (there are several): I'm using the 0 261 200 489 ECU The ECU# is Coded Backwards, beginning at $07EE7 on the factory chips. This ECU code # is in ASCII on the chip. In front of the ECU# is the firmware vers#, for 1994 348 Spiders it is: 1 267 356 497. The CRC for the chip must correspond to the above firmware and hardware #'s. (for 1994 348 Spiders the CRC is 0611) Bosch/Ferrari uses a "CRC" check to verify chip integrity (read: keep people from easily modifying these bad boys). So when you turn your ignition key to "On," each Motronic ECU reads the chip and calculates the CRC that should exist for the firmware/hardware numbers that are coded on the chip. This means that if you change the firmware #, that you have to have a new CRC. Since I don't know what new CRC is required, I'd suggest leaving that part of the chip alone...because, if you leave it alone then all that you need to do is to have a CRC value of 0611 after you've made your changes to your chip. To adjust your CRC value you change the OEM hex FF's between 6590 and 65BF to smaller values. Then you use the "Calculate CRC" function in your Batronix editor (free software with your EPROM burner). You keep changing those FF's until the CRC function returns an 0611. This will adjust the CRC result back to 0611 after you've made any changes to a chip. IF the CRC does not match the firmware+ECU# above then your CEL will always be illuminated and Bosch will run you in a limp home mode (I dyno'd a 25 rwHP loss from stock, cause yeah, I learned this the hard way).
Hmmm... the above post might come out of nowhere for a lot of casual readers. Basicly, if you make a change to a Ferrari 348 chip, you have to tell the Motronic 2.7 ECU that the change was "Authorized." Otherwise, M2.7 will run you around in limp home mode with your CELs illuminated. To be "authorized," your chip (with changes) needs to have the same CRC answer as the stock, unchanged original OEM Ferrari chip. To get that same CRC answer, you've got to change some "spare" data bytes. Make a lot of changes to the fuel and sspark tables, then you'll be changing a lot of spare data bytes. But just bump up a single byte by "1" in a single fuel/air table, and you might just need to subtract "1" from a spare "FF" value, making it into an "FE" value so that M2.7 calculates the same "0611" CRC from your chip as it would for the OEM chip.
I could write a program to make the CRC calculation easier if it would help. Basically, read the rom.bin and fiddle with the pad bytes programatically until the CRC matches, sort of reverse error correction. Might be a bit quicker than making a 1 bit change and having the eprom programmer re-calc until you get the right bits. Anyone know which polynomials they used ? (Just out of curiosity)
Well, if we're going to have an ND chip thread, then people are going to need to know how pull out their old chips and how to insert the new chips: http://www.club348.com/technical/Tech/ECUnchipHow2/Howtoaccessyour348ECU.htm
That would help, but the task isn't overwhelming by hand, either. Since you know that you want 0611, you just need to calculate the difference in the stock file vs the modified file. That's how much you have to adjust the "spare" hex data. So if you added 41, then you've got to subtract 41 to get back to 0611. Should be a simple matter to calculate that difference in the original vs modified file.
Likewise, people need to know how to adjust their 348 and Mondial T MAFs: http://www.club348.com/technical/Tech/348.html#AFMixture And of course, the hardware and software required to scan/burn chips: http://www.ferrarichat.com/forum/showthread.php?t=150962&page=4
for M2.7 6CF0[]: = f( Load (ms), Engine RPM ) *Fuel curve tj (4838[]: for M2.5) NOTE: the TPS chip bumps up each value in this table ~~ +6 starting at 6D08 --------------------------------------------------------------------------- ThrottleVoltage..4.20.......4.60....5.00....5.50 ================================== RPM:800.Values:.9D...........8D......92.......8D RPM:1160...........89..........7D......70........67 RPM:1280...........83..........78......73........65 RPM:1520...........8D..........7D......6F........6C RPM:1920...........8A..........89......80........77 RPM:2240...........8A..........86......85........85 RPM:2520...........8D..........89......86........86 RPM:3000...........8D..........8B......88........88 RPM:3520...........8D..........8D......87........86 RPM:4000...........8D..........8C......8B........86 RPM:4520...........8C..........8B......8C........8C RPM:5000...........8A..........8B......89........87 RPM:5520...........8F..........8F......8E........8A RPM:6200...........96..........96......95........95 RPM:6800...........99..........98......96........96 RPM:7720...........97..........96......95........92
That was all super greek to me. I'm going to buy the innovate wideband that can collect data and download to a laptop. I'll send you data and see what you think.
Cool. Also, a timing light so that you can show "how much" the spark timing is being advanced would help.
Yep pretty geeky thread, but not completely alien. ND, please make sure you provide any necessary caveats about your mods when cars are or are not running cats AND comments about smog compliance - really just your educated opinion. A really rich A/F may be good for power, but it that richness persists into the cats, you might end up with problems. For example, Bruce and FBB do not run cats on their cars and can be more aggressive in this area, ISTM, while my car retains its cats and (hopefully) smog compliance. Regarding the timing light - do you mean to check the car under idle for advance? I can't see how you could check spark advance while underway. Maybe have someone rev up the motor while you scan the advance. Simply stated (and at the risk of exposing my ignorance), we can explore the optimum mixture (fuel and air ratios and spark advance) at different rpm ranges to make the most power under a known set of variables (like engine mods). A stock car is set up pretty well from the factory, but ND can refine the curves. Once you start making changes to the OEM equipment, it becomes a process of tailoring the curves to match your mods. A simple example is if you install a K&N filter, pull the cats and change the exhaust to a free flow model, you can beef up the fuel air tables and advance the spark a bit. Richening the A/F reduces knocking, like running higher octane fuel does, so you can advance the spark. We need to keep in mind that this is a process of inching up to the optimal point. Once you go past, you could end up with a damaged motor. In my car, we are making all these changes and more, except the cat removal, to see how far one can push the stock engine and keep it smog legal.
Hey Vince, please keep in mind that I'm no expert. I'm just a simple 348 owner like yourself. Sure, I've dived into the Motronic chips, but they are only complex because the factory has kept the specs a secret. What the Stooges are doing is putting in some time, effort, and personal risk to reveal those secret specs. Right now, changing a "43" to a "44" is an unknown in the sense that we don't yet know if that advances timing by a tenth of a degree, half a degree, a full degree, or what...but at some point in the future we will know. How much extra power will it give? Well, we know a little bit about that because we can see the before and after dyno improvements after we burn new chips. Look at the MAFs, too. We know that lowering the MAF resistance makes our 348's richer across the entire rpm band, but we don't yet know if lower the MAF resistance by 10 ohms means going from a 14:1 to a 13:1 air to fuel ratio. Same with your tb boring. We can't yet say that goin 2 mm wider yields + or - on the air to fuel ratio, but soon enough we'll know. Ditto for how running richer impacts cats. I'm running stock cats. Surely I'll be the first to see the cats go if our mods aren't getting enough fuel burned! Yesterday after two quick full throttle dyno runs and a brief cooldown I hit my cats with a laser thermometer and was stunned to see them read a mere 414 degrees F. So we're learning as we're going. And we're going to make some mistakes. That's OK. We'll get the information out there so that others won't have to reinvent the wheel.
I hear you loud and clear, ND. But you are wrong about one thing - you are our resident expert on the chips if only because no one knows any more than you! I am glad to hear about the cats temp - actually, I thought you were cat-less. We are sure having fun!
OK, some potential progress on Ferrari's "chip verification" scheme. Starting at hex address 7EE7 and going to 7EFC are the Bosch part # for our ECUs as well as the Bosch firmware # for our fuel/air/spark/dwell maps. These hex values for the 348 spider add up to 0610. Having a CRC value of 0611 on the above 348 spider chip will accordingly pass Ferrari's test for "chip integrity." So one has to think that changing the hardware and/or firmware on chips that we burn will change the needed CRC value to a very similar answer...such as those values adding up to 0650 might very well mean that a CRC of 0651 would likewise pass the "chip integrity" test. The "chip integrity" test isn't all bad of course. EPROMs can actually lose/corrupt their data over time (this is why backups of our factory ECU firmware chips make sense). A bad EPROM...or one that is burned with a CRC that doesn't corespond to the firmware/hardware data...will turn on your CELs and cause the Motronic ECU to run in a power-diminished limp-home mode (which I've witnessed firsthand in an actual dyno test run).
http://www.motorart.net/seaita/database/originali/FERI_348.HTM ......................ECU #................Firmware #.....Checksum.....Chip Type....RIF (?) FERRARI 348 ... 0 261 200 190 ... 1267356227 ... 39D6 ......... 27C256 ..... 179 FERRARI 348 ... 0 261 200 489 ... 1267356497 ... 0611 ......... 27C256 ..... 942 FERRARI 348 ... 0 261 200 457 ... 1267356410 ... D818 ......... 27C256 ..... 277
Looks like Ernie was correct: we *can* program our M2.7 and M2.5 Motronic ECUs while on the dyno via our laptops! http://www.moates.net/product_info.php?cPath=50&products_id=169 Image Unavailable, Please Login
