Apexi SAFC-I

[andyeagle19]

Any thoughts on this fuel controller? Looking to buy a SAFC-I. Just like to hear your inputs on on it. Thanks

Sab

[JekylandHyde]

It works, but let me offer you some caution if you are using it on a turbo MR2.
As you lean out the fuel for more power, the ECU will advance timing.

Too much lean fuel with too much advanced timing = boom.

I've been tuning with an SAFC for a 2 yeras no with no problems, but others have popped motors from getting to aggresive.

[andyeagle19]

Thanks for the advice, any pointers in tuning??

Sab

[JekylandHyde]

I would get an adjustable FPR:
www.trueleo.com/fpr.htm

OEM base-idle FP is 36 psi (with no vac applied).
If your base runs show that you are rich across the board, lower your FP to 33 psi and do another run.
If you are still rich across the board, go down to 30 psi. I would not go below that.

Lowering the FP will not cause your ECU to advancing timing. Once you get the FP set, start making the smaller changes on the SAFC.

I would say to do all of this since it will reduce how much you need to take out with the SAFC.

[andyeagle19]

Thanks again, is there any way to safely tune the SAFC without the FPR?? Just a little short on cash at the time.

Sab

[JekylandHyde]

I would only make small adjustments.
How are you planning on tuning?

You should really do it on the dyno or with a wide-band O2.

[andyeagle19]

What exactly is a wide-band 02 sensor? Just a clarifier. Yeah I only planned on doing small tweeks with it. I will probably tune it on the dyno in a month or so. Appreciate the info.

Sab

[JekylandHyde]

The O2 sensor on your car is a narrow band unit. It can only read so far from rich-to-lean and it is only used for idle and cruising.

In order to tune at WOT, you need a wideband O2 ... something that is much more accurate and can read overa wide range.
When you dyno-tune, they stick a wideband in your exhaust pipe.

There are also wide-band units you can buy that give you read outs in the car. I just got one for $320 shipped (inlcuded the software, the O2 sensor, the bung and the piece of equipment that interprets the signal).

[andyeagle19]

Alright I will probably end up getting that as well. What are your thoughts on the SMT6 piggy back computer?? Thanks for the o2 knowledge.

Sab

[JekylandHyde]

I know absolutely nothing about the SMT6.

[andyeagle19]

alright!