July 1, 200619 yr an old Apexi Super Fuel Air converter on an old Ru? It says its vehicle specific, but its such a simple device... maybe some rigging could be done?
July 1, 200619 yr that is a SAFC? IIRC they can be used to compensate for larger injectors, and will probably work pretty well with an older system that doesnt "learn" like obd2. I have seen them installed on several obd1 cars too. I used to have a write up of an install on an impreza but dunno. they are way cheap too, like less than a bill but they are kinda old school and ghetto. they use a bunch of knobs you turn to tune it right?
July 1, 200619 yr i think theres a voltage issue with older subes. our maf is 12v and the safc is 5v or vise versa? its something along those lines. check in retrofitting too.
July 1, 200619 yr Ohh Bobbo... Are you trying to rig something up for the ER27T? I decided that the modification we are doing deserves it's own ID. I think its only appropriate for mechanical genius' such as ourselves. Ok, maybe genius is a little strong. Maybe... schizophrenic? Maybe... I'm a very good mechanic... definitely good mechanic...definitely... good with wrenches...yeah, wrenches. Remember, Dave said the motor would take 14psi with the stock ECU and injectors.
July 1, 200619 yr unless you get a converter for the signal going into and out of the safc, it wont work. you will hit fuel cut at part throttle, or something like that. the stock system uses a 12v signal from the maf and the safc is for newer cars that run a 5v signal. john, you had it right the firsst guess there man.
July 1, 200619 yr Author changing it from the Maf to the safc would be cake... getting it back on the other had.......:-\
July 2, 200619 yr I'm not familar with the system, but if it uses a 5v ref and the Sub ref is 12v it seems to me you would just have to figure out the proper resistor to install in line to achieve the proper volatge/current drop. This might however effect the 0 - 5v reading you are trying to get. And then the issue of, will the signal be clean enough. JMTC
July 2, 200619 yr Author how bout this everyone.... is there a car out there from the early 90s that uses the same or a similar MAF? Maybe like an MR2 or a nissian or something?
July 2, 200619 yr how bout this everyone.... is there a car out there from the early 90s that uses the same or a similar MAF? Maybe like an MR2 or a nissian or something? I would presume "same MAF" would also have the same voltage problem. You might be able to find something that will generate the voltage you need (i.e. be a 5V MAF) that will fit in the same location or style, is that what you are looking for? If so, my money would be on a 300ZX-T or RX-7 3rd gen.
July 2, 200619 yr 2nd gen RX-7s have a mass airflow sensor that works with 0-5v, 3rd gen RX-7s don't have a MAF - the use a MAP system. You could make a SAFC/AFC/etc work, but you'd need active voltage division before the unit, and multiplication afterwards. You could do it fairly easily with a few opamps - a 3x divider/multiplier should be fine. The problem, as pointed out earlier, is that the EA series Subarus have a 10-12v MAF sensor, and the SAFC units work with a 5v signal. It'd work fine until you hit 5v on the MAF, then it'd clamp & the engine wouldn't run beyond that airflow. If anyone's interested in playing with this, let me know - I could whip up a voltage divider/multiplier set & send it out for you to play with. I have a SAFC-II in my 2nd gen RX-7, so I'm fairly familiar with the units. -=Russ=-
July 2, 200619 yr Author I'm intrested... I "might" be getting one from the korean.... if he decideds not to horde it for himself (since its his:grin: ) I'll go on my 88 RX for now since computers are plentiful for it if I toast it
July 2, 200619 yr if you make one that works for these cars, im down for one. i need some kind of tuning aid on my car, ive upgraded the turbo, fuel injectors and ignition, but now i have no way of making sure everything is tuned right for it.
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