Why is an SAFC II such a bad Idea with a Turbo Neon
Why is an SAFC II such a bad Idea with a Turbo Neon
I have read countless threads and have had people backlash on me when I mention using a SAFC to tune my car when I go turbo. I never got a good response as to why. I have tuned 5 or 6 turbo'd cars with a wideband and SAFC.
So my question is Why is a SAFC II not going to work well on a boosted neon?
So my question is Why is a SAFC II not going to work well on a boosted neon?
Dunno, prob most just go with MS. It IS the way to go
SuperCharged SOHC http://forums.neons.org/viewtopic.php?t ... highlight=
Samu wrote:If you get rid of your 1st gen it will be like the girl that got away.
It works ok on a lot of cars, just not the neon. One of the biggest problems is that the more fuel you take away with the SAFC, the more the PCM advances timing. Thats bad for boost. Real bad.
Another issue you run into is trying to get the engine to idle properly with big injectors and stock fuel pressure. In order to do this, you again have to pull fuel with the SAFC. The problem is that the MAP is already reading low kpa, and clamping the voltage lower causes it to be out of range. The PCM will never get a correct barometric pressure reading because of the same problem.
The ideal setup is to use an SAFC in conjunction with an FMU. The FMU will tune the basic fuel needs, while the SAFC can be used to "fine tune". I ran this setup for a while until I switched to MS.
Another issue you run into is trying to get the engine to idle properly with big injectors and stock fuel pressure. In order to do this, you again have to pull fuel with the SAFC. The problem is that the MAP is already reading low kpa, and clamping the voltage lower causes it to be out of range. The PCM will never get a correct barometric pressure reading because of the same problem.
The ideal setup is to use an SAFC in conjunction with an FMU. The FMU will tune the basic fuel needs, while the SAFC can be used to "fine tune". I ran this setup for a while until I switched to MS.
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a safc is ideal for a all motor car. but turbo cars with mass flow sensors work the best with them.....when the neion goes in to closed loop ie cruise it uses pre burned maps and ignores the safc... in boost and cruise thats bad. a 1:1 or if you use a rrfpr then you dont really need it just a wideband and a quality rrfpr and say a set of stage 0 injectors. ms would be the best way to go. but a rrfpr and stage 0 injectors would do. this is one area that you dont wanna skimp in.. you mite go boom.
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I've tuned many boosted cars with an SAFC, it doesnt tune by the rpms you control the amount of fuel pertaining to your AFR. I usually use a wideband and tune it at full throttle. It will run rich when your not at full throttle but its much safer then running lean.Armstrong57 wrote:SAFC tunes fuel by rpms, not by boost. You want to be able to control fuel as it pertains to boost levels.
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Its basically alpha-n (RPM specific) tuning. The SAFC has no way to tune the difference between 5 pounds of boost and 15 pounds. It adds or subtracts the same amount of fuel regardless of manifold pressure. Since we obviously need more fuel at 15psi than we do at 5psi (at the same RPM, of course), you can see why the SAFC can be less than desirable.
The unit does, however, have the ability to adjust its tables based on throttle position. This is a way to infer manifold pressure at part throttle boost. Not a very accurate way, but it works to some degree.
There have been many people to do the "AFC hack" install. This is just wiring the SAFC up so that the MAP sensor is hooked to the units throttle position input. As manifold pressure changes, the SAFC sees it as a varying throttle position and adjust fuel accordingly. A high MAP reading would make the SAFC switch to the "high throttle" table.
The unit does, however, have the ability to adjust its tables based on throttle position. This is a way to infer manifold pressure at part throttle boost. Not a very accurate way, but it works to some degree.
There have been many people to do the "AFC hack" install. This is just wiring the SAFC up so that the MAP sensor is hooked to the units throttle position input. As manifold pressure changes, the SAFC sees it as a varying throttle position and adjust fuel accordingly. A high MAP reading would make the SAFC switch to the "high throttle" table.
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You can tune the car with the SAFC, and it may be safe enough to run, but it won't be optimal. If you got that much hp tuning with SAFC alone, I'm sure you could get even more (and more stable) with the proper tuning method.
If it's working for you, do it! But all we're saying is that it isn't the most optimal way to do it for a boosted setup
If it's working for you, do it! But all we're saying is that it isn't the most optimal way to do it for a boosted setup
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get a rebuild kit from modernwesker wrote:could that be why im smoking now.a guy on neon.org told me 49 psi on the fpr and a 10:1 fmu.im taking out this engine a putting a low,low mileage 95 motor in it.i want to do it right this time.
The definition of a NEON
A great domestic compact car whose rapidly disappearing taillights are most typically seen through the windshields of Honda Civics, Chevy Cavaliers, and other assorted shitboxes.
According to Urban Dict. dot COM