Apexi SAFC II Tuning

[Mike@Fidanza]

Anyone here have one of these?

Anyone here know how to use it?

I am aware in order to properly tune the vehicle with this unit you must have a dyno, but the dyno guy over here doesn't know too much about it...

Thanks!

[turbonatormr2]

Originally Posted by Mike@Fidanza

Anyone here have one of these?

Anyone here know how to use it?

I am aware in order to properly tune the vehicle with this unit you must have a dyno, but the dyno guy over here doesn't know too much about it...

Thanks!

I would not recomend using this unit for the following reason. I am not a big fan of piggy backs.


Piggy backs cons.
-REMOVE FUEL, ADD TIMING:
This is by far the LARGEST concern on SELECTED piggybacks. When you use the piggyback to control larger then stock injectors you typically interface the MAF/AFM/MAP sensor and modify the signal going to the ECU. So say you have to pull fuel because your larger injectors are dumping to much fuel what happens is the ecu thinks there is LESS air entering the engine thus thinking there is less LOAD, well less load means that its safe to advance the timing to help with combustion. While this is fine for when you really are not putting a large load on the engine (IE off boost), this can be DEVASTATING to your engine in that since the timing has been advanced in a high load area the chances of detonation is greatly increased!
This is why I DO NOT recommend the S-AFC unit to anyone because of the fact it cannot control timing (or at least have the ability to retard it).

[Mike@Fidanza]

I'm not using it to control larger injectors. i'm using it to lean out the AF a bit at higher rpm/boost levels. on the dyno last year it was running way too rich. i adjusted the timing a bit and still ran too rich. it's just a temp. thing!

[JekylandHyde]

Mike, the SAFC is a fine piece of equipment to use on most cars.
There is an inherent risk in using one on the 3SGTE.

The SAFC leans out fuel by lying to the ECU about the amount of air coming in through the AFM. Our ECU's, when they see less air coming in, start to ADVANCE timing.

advanced timing + leaned fuel + more boost + high rpms = BOOM

Many MR2's 3SGTE's have died this way. I ran an SAFC for several years with luck, but I was always using race gas and water injection. You do not need a dyno to set up the SAFC, but you do need a wide-band O2 sensor.