|
Yes, if you richen up the afc, it will increase your MAP sensor voltage, and thus the car will see that there is more load on the engine and, consiquently, reduce timing. What would be ideal for you to do as of right now, would be to richen up the afc as much as you can, and decrease your fuel pressures. If you do this enough, you "should" be able to get away without an MSD up to about 15 psi.
If you have an adjustable regulator, what you need to do is to set your idle fuel pressure to around 20 psi of pressure. Then richen up the afc until your STFT looks acceptable. Then re-tune the regulator to supply enough fuel with the new, richer settings on the afc. I would be willing to bet that you could get your timing to come down to around 18 deg of advance at 15 psi or so, which should be about right on.
For those of you sho have larger injectors with an safc, you really should be droping your fuel pressures and correcting for the lower fuel pressure by richening up the safc. When you lean out your fuel delivery on the safc, it reduces the MAP voltage. This is what causes the car to advance more timing and can result in engine damage if the timing is too excessive. If you can drop your fuel pressure and correct for it by richening up the settings on the safc, then it brings your MAP voltage at WOT back up to close to 4.5 volts. This way, the ecu can read more accurately the amount of load being placed on the engine and it will adjust timing accordingly. If you can keep the timing advance to around 15-18 deg of advance at around 15 psi, you should'nt have to buy anything to pull timing out as long as you dont boost any more than that. I'm not sure at what point our cars will need spark amplification, but my guess is that 15 psi is nearing that mark.
By the way sonikbewm, if I were you, I would just ditch the safc with 310cc injectors. If you have an sfmu, you can easily run those injectors without an afc, and consiquently, you won't have to tamper with the MAP signal at all. This should correct for your timing being slightly high. Although... if you were feeling like experimenting... you could drop your fuel pressure to around 15 psi at idle and try to use the SAFC to increase the MAP voltage slightly above 4.5 volts (by richening it up as much as your fuel trims will allow for). I'm not sure at what MAP voltage the car will give you fuel cut, but I estimate it to be around 4.7 volts. I am curious if our cars will reduce timing further with a slightly higher MAP voltage than 4.5 volts. My guess is that it will, in which case you could possibly pull timing enough this way to get 15 deg of advance at say 20 psi of boost... I would be very interested to see if this little trick could give you guys with an SAFC a way to acutally pull timing out slightly rather than advance it.
Matt
1995 Eclipse GS
2.0L, S16g Turbo, 8 Injectors, 26psi
1998 Eclipse GSX
2.3L Stroker, AEM EMS Converted to Speed Density, FP3065 Turbo, 35psi , and so on...
|
Search
Printer-friendly copy
2 Users in Chat
