Today I dyno'd my ep at Jotech Motorsports in Dallas. Vital stats are as follows: 5:06 to 5:26 pm, temps were cool, low 60s, hood open, Dynojet dyno. My car currently has stock airbox w/ Hondata modifications and a drop in K&N filter, stock header, ebay test-pipe, MBRP 2.25" mandrel bent mid-pipe, 02blksi ground wires, and fresh Mobil 1 0w20. Rims are 16" with 205/40/16 Kuhmos, approx. same weight as stock, not sure of brand(!). All runs used 87 octane.
Runs 1 through 3 were performed in 4th gear and the numbers are as follows: 135.1hp, 134.8hp, 137.4hp. Run #3 was the best, with 137.4hp/120.4tq. My A/F ratio is somehat rich and I do show a cel from the test pipe. Jotech's Snap On scan tool cannot read the code, refering to it as a dealer specific code, but it can reset it. Resetting the code did not show any power gains or A/F changes. These numbers are not spectacular but considering the 87 octane and lack of intake/header I consider them acceptable.
Here is where it gets weird. I decided to make a 4th run, only this time in 3rd gear. On this run my power dropped significantly, down to 111.7hp/90.7tq. The A/F ratio was significantly richer throughout the entire run. I made another 3rd gear pull with similar results. At this point the oil is checked and I have plenty and it looks good. So the tech checks all the dyno connections and they look fine as well. So now we do another 3rd gear pull and again, the same low hp/tq numbers as before.
We tried another 4th gear pull and power jumped back up to 135hp. At this point I have made about 8 runs for the price of 3 so we call it a day.
Does anybody have any idea what is going on here? On the road my car feels fine, pulls well through all the gears, and fairs well against the competition. I was expecting more power, especially with the test pipe on, and now plan on changing all fluids, plugs, and getting my cel read at the honda dealer. Any help, ideas, etc. are appreciated.