Greetings all. Have been too busy working, but still getting the 328 out for a drive every now and then. Have not been active on the forums, so maybe I missed something. A while back, there was a discussion about reverse engineering the little black box that has a sensor in the exhaust that controls the "slow down" light. I wanted to see if that has been discussed anymore, or if someone actually has worked something out. On my last drive, my light was on / off for about five miles total, out of my 100 mile drive. Thinking that if someone has a option to replace the "black box" in the trunk, I might go do that this winter. Any advice would be appreciated.Enjoy Bob
Cant help with the answer but DEFINITELY would like to see if any progress has been made in "re-creating" the slow down module. It's been quite a long time now since someone on the site posted that they had sussed it out and was going to be able to make the module but it all just faded away. I have a lot of experience with vintage electronic repair and, it seems to me, if someone figured out the specific circuitry/parts necessary, anyone that is capable with a soldering iron/circuit board could assemble the parts to do the job though, of course the module wouldn't look like the OEM module. But I, as you, are hoping that something eventually comes of this!
Let me first state that I am not an electrical engineer so perhaps I oversimplify. But rather than attempting to reverse engineer the troublesome sealed module, why not merely design a circuit that turns on the slow down light when the leads from the thermocouple exhibit an emf that corresponds to a temperature that is above a safe threshold. The circuit would be completely independent of anything else.
Both versions of the slow-down ECU 1985-87, and 1988 are shown to be available from Ricambi. Why don't you just buy a new one?
If the module is now available from Ricambi, then, of course, that takes care of the issue! Last time I checked, which was probably a year ago, the only replacement modules were modules taken off an existing car and since they are well known to fail, it made no sense to buy a used one. That's why there was considerable interest here when someone said they had figured them out and could make them though nothing came of it.
Back at the time this was discussed before I contacted Ferrariparts and asked if they would be interested in having these duplicated as an official part, for 355 specifically. The answer was they already had someone else working on it, so if they are now available it seems this was done.
This topic was recently discussed: https://www.ferrarichat.com/forum/threads/308-gts-qv-catalytic-thermo-sensor-probe.563084/
Thanks for the information. Sounds like factory ones are still an option, and that seems like the best way to go. I was curious if anyone has tried the "home made" version that was discussed earlier? Thanks
I was under the impression - possibly incorrectly - that no one had actually produced a home made version that actually worked or, at least if they did, they didn't explain the circuitry so that the "rest of us" could cobble together a working replacement module.
There are many stand alone egt kits out there. And they are pretty cheap compared to the Ferrari stuff which is basicly junk anyway.
AFAIK, there are NO stand-alone aftermarket egt kits that restore the OEM function of the slow-down light system on these cars. If you want something that provides the info and you are OK with a hang-on/bolt on display or gauge of some sort, then certainly, many options are available; there's one on Amazon for 20 bucks! It all comes down to whether you want it to work as OEM or you are OK with an added readout device somewhere in the cockpit.
FChat member "jmaz" (Jim) has analyzed working modules from both his 328 and my 308 and has reverse-engineered working prototypes. He has schematic drawings (as well as his home-built prototypes) of the modules. He is a university professor and not much into production and marketing; he just likes figuring out how things work. As I posted earlier, here is the thread discussing the system: https://www.ferrarichat.com/forum/threads/interest-in-slow-down-light-cat-ecu-substitute.498691/ As Jim explained to me, the modules don’t do much; they just receive the thermocouple voltage as an input and, at a trigger voltage, sent a power signal to the Slow Down Light bulbs. The modules could easily be made so that the lights begin blinking as the cats near critical temperature and then light constantly as the critical temperature, or could blink out messages in Morse code for that matter. I would suggest PMing jmaz and see what his plans are for building the modules or posting the schematics. EDIT: I have Jim's personal email id and have emailed him alerting him to this thread.
I got an email response from Jim. He has not been checking FChat lately, but intends to post a reply sometime in the near future.
Brian Thanks for your response and for getting the information. Look forward to hearing from Jim Enjoy your Thanksgiving........
Things are moving forward on the cat ECU replacement effort. I'll hopefully have some concrete news to post within a couple of months.
