EvilChief

ok here is my idea of the month ...

after playing with my mates skyline last night (till 3am) and reading his instruction manual for his SAFC, i found that all my sensors are within range like his.

so I am wondering if I could run a SAFC or SAFC II to tune my car. I have a S3 crow cam with rhe usual bolt ons, but no ecu adjustment and my AFRs are quite a bit all over the place ...

for those who are not too familar with SAFC, its and adjuster for the MAF/MAP sensor (similar to most interceptors or chips), basically you use the follwoing:
- TPS
- MAP/MAF (for alteration)
- RPM

it uses TPS to determine HTP (High Throttle Position - 15% - 80%) adjustment maps and LTP (Low Throttle Poistion - 0% - 15%) adjustment maps.

RPM signal for abviosuly determining rev range, so you can dial in the adjument factor

MAP/MAF signal get intecepted and altered depending on MAP

that is pretty much all it does, so this way you can adjust the AFR, by tricking the ecu into thinking there is more or less air coming in by altering the MAF/MAP signal

TPS signal: (pin 89)
Throttle @ Idle Position...................................... 0.55 to 0.85 Volts
Throttle @ Wide Open Position.......................... 4.0 to 4.5 Volts

MAP signal: (pin 34)
Pressure @ 10 kPa.......................................... 0.4 Volts
Pressure @ 30 kPa........................................... 1.2 Volts
Pressure @ 50 kPa........................................... 2.0 Volts
Pressure @ 70 kPa........................................... 2.8 Volts
Pressure @ 100 kPa......................................... 4.0 Volts
Pressure @ 115 kPa......................................... 4.6 Volts

RPM: (pin 45)
Engine Running................................................. 0 to 12 Volts Square Wave

the only signal wire i am worried about is the RPM as even minor signal loss can cause major issues (as we found out last night on the skyline - we were making our own tuning interface to datalog all vital sensors for tuning, O2, boost, TPS, MAF, etc, but it had major issues with the RPM signals. we traced it back to the fact that its a coil pack cars and without accurate RPM signal it doesnt know when to fire each cylinder, hence it was dropping cylinder at random and just guessing for each cylinder when to fire.)

ay ideas or experiences in that area, eg someone tried it before.

btw no need to tell me i am nuts to put jap crap on my falcon i already know that)

cheers
mic

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EDXR8

It should be okay but will obviously take a bit of work to get correct. The problem with mods like cams on the I6's is that it throws out the MAP sensore therefore the engine load figures. Don't know about the AU's but the E-series cars have a rpm output for tach in the diagnostics port under the fuse panel in the cabin. Otherwise I am sure you could get the tach signal from one of the EEC wires.

EvilChief

the good thing with the SAFCs, the base maps are pretty much spot on to begin with, for skylines that is, so if i get a NA skyline SAFC basemap i should be reasonably quickly getting there
oterhwise i put together my own maps, which isnt too hard.

we just put together a trace plug wideband O2, so we can follow up rpm by rpm whats going on

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EvilChief

the service port rpm output might be a good option for the trace program and my shift light,you wouldnt happen to know which pin it is?

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