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View Full Version : what do you set afc to with cobra maf?



Evil_rps13
02-15-2003, 10:32 AM
I was just wondering if anyone knows what you set the afc to running a jwt ecu and cobra maf? thanks.

asad
02-15-2003, 01:06 PM
While I haven't done it, I will tell you this -- basically all hotwire MAFs have a very similar output curve -- not surprising since they all are based on the same physical principle. In other words, for any 0-5V output MAF, the shape of the curve will be very nearly the same for ALL MAFS.

The difference between different MAFs is what airflow any given voltage corresponds to. But...if all you want to do is slide up and down the same curve, then it doesn't matter what the absolute airflow calibration is. That's only important when you want to switch MAFs.

Because MAF voltage curves are similar in shape, you should be able to use basically ANY of the hotwire MAF settings of the S-AFC. Look, for example, at the HKS Super-AFR. It has only ONE setting for basically all hotwire MAF cars (with one exception) -- but the caveat is that you can't switch MAF types with the Super-AFR.

So...if all you want to do is run the Cobra MAF with the S-AFC and a JWT Cobra MAF ECU program, just pick one of the HW settings and use it for the in and out -- and it probably doesn't really matter which one. The only downside to this is that the "percentage" correction values might not be super accurate. In other words, due to the slight differences in the shape of the MAF output curve, if you set the S-AFC for, say, -15% at one RPM point, it might actually correspond to something like -13% at that RPM point, whereas at another RPM point -15% might correspond to something like -17%, or vice versa -- which isn't really a big deal, as I'm sure you won't just be setting the fuel correction without testing it.

Asad

Evil_rps13
02-15-2003, 01:11 PM
Thanks asad, and your right i won't just be setting it as i have a wb 02 to tune with. thanks again.