Your mileage may vary...and I suggest that your focus on the end number misses the nuance in the data and the dozens of variables that may lead to a wide range of results. See, for example, customer dyno results posted on page 6 of the dyno thread wherein he got 11.8 at the wheels from just our RoadsterSport Race and a K&N Drop in....but our results from just a K&N panel drop in were consistently zero to negative (which suggests he was getting more from the exhaust than we have ever got here, or?). Each car is different, lots of variation in dynos, some motors assembled better than others, Mazda has about two dozen different ECU calibrations and some respond better than others (some add the header and get perfect air fuel ratios without a reflash and others are too rich and need a reflash to optimize the results), and on and on. Thus, if your expectation is that every NC will get the same precise result that we got, or that any one customer got...then that expectation is NOT realistic and I can burst that bubble now and guarantee you will not get the same gains on every NC. That's a conclusion that you would find in that long dyno thread over and over....as I wrote in that dyno thread back in 2007:
"That dyno above is on our 2007...which is not stock. For reference, our 2007 started out stronger than our 2006 by nearly 10 horsepower (141 for the 2007 stock versus 132 at the wheels stock for our 2006 peak) on the same dyno. Why? Don't know. Perhaps our 2006 was just too new and tight when we did the baseline, perhaps Mazda has changed the flash program they are putting in the ECU now and the fueling is now a little tighter than the pig rich we saw in the 2006, or perhaps even a little more spark advance; or perhaps our 2007 motor is just screwed together better, don't know. On a separate but related note I will add that we are consistently seeing weaker results with mods to the Automatic transmission NCs. Why? Don't know but it is reasonable to theorize that they have a more conservative state of tune...perhaps a more conservative timing curve or fuel curve. Either way, I understand that for 08 Mazda is going to re-rate the auto equipped cars down a few HP from the manual transmissions and I suspect this is merely acknowledging the more conservative tune that our results have been evidencing. I don't think this means tuning an automatic is a waste of time...but our experience so far suggests that those with the auto trans may expect small gains...at least until such time as we have ECU control over timing and fuel."
The funny thing about my 2007 is that motor did turn out to be a REALLY STRONG example. Further in the thread we get to when the Cosworth supercharger gets added and we turn about 260 hp at the wheels....or about 50 more than anybody at Cosworth expected or even hoped to see. We were so alarmed by the results that we ran across town to another dyno the next day and repeated the tests....and still hit way over 260. To this day I have never seen a Cosworth powered NC on stock boost level repeat that result. My 2007 later got a hot Cosworth built motor (using stock crank) and it could not repeat that strong showing on stock boost with same ECU calibration, same dynos, etc.