I just replaced a split second kit with the miller maf. It is pretty good. It replaced a split second map box, which replaced a modern performance piggyback maf kit. The modern performance signal box failed on the board at the tuning pot solder joints. Joe Shaw had the same failure on his modern perf. maf. Modern performance went out of business a couple years ago.
The split second psc-001 with internal map sensor was good around town, after too much tuning on my part. It used a tach input to vary the same map signal for different rev ranges. It wouldn't have been worth a crap without the tach signal. I was trying to get some info from split second on adding another signal, from a throttle position sensor to correct a problem with lean running when climbing hills on the highway; the map signal didn't change quickly enough to tell there was higher load at speed. The incoming air at highway speeds masked the vacuum loads with a partially open throttle. On my 535, partial throttle & wot both showed -2"Hg in this situation. Split second denied the manual's instruction that 4 additional inputs could be used to further tune the signal. I could have used the split second box in another mode with a maf sensor, but split second wouldn't send me a base curve to start with, & I wasn't interested in starting over with the split second stuff.
I like that the miller kit uses a remapped dme chip without a piggyback, especially after the failure(s) I've had with previous piggybacks. It runs well with my somewhat modified m30b35.
My lc-1 wideband indicates that the miller maf runs just a smidge fat under 2,500rpm; I may be able to correct that with the adjustable fuel pressure regulator & the lc-1's adjustable output signal to the dme. The miller aluminum maf housing is heavier & bulkier than the plastic ford maf that modern performance used. Also, the miller maf isn't the usual ford maf; it works with other ford mafs, but the signal ends up lean with the modern performance maf. The plug & sensor fitting are different. I like the Miller maf & anticipate no problems like I've had with the other stuff, because it isn't a piggyback, but a sensor & replacement chip.
I ended up down blinging the maf housing a bit.
I've just replaced the miller maf housing for a 3" tube. It is better, more like the performance of the modern perf maf with the less restrictive tube. I did have to raise the fuel pressure to normalize the tune, per the wideband lc-1. Also, this maf tube doesn't act like the heat sink that the miller maf aluminum chunk is. That heavy thing stayed hot for hours.
