I have a 2007 AP2 with a 63mm test pipe and Injen CAI. I have been tuning using Flashpro on and off for a couple of years. It's been a fun, challenging hobby. Up until recently, I had reduced my VTEC crossover point to 3600 rpm based on previous great info on this forum provided by Gernby and others. The lower VTEC engagement felt more power for sure based on road dynos using the PerfExpert app. This app works pretty well especially if you perform several runs and average the results. I finally decided to use the app to test the method suggested in the Flashpro tutorial to determine the "optimum" VTEC crossover point. I took my current tune (3600 rpm VTEC) and saved it with a reduced the VTEC crossover of 3000 rpm. I then also took my current tune and saved it with an increased VTEC crossover of 6500 rpm. I then found an unpolulated road and did three 3rd gear WOT runs from about 1500 rpm to redline (8500 rpm in my car) as consistently as possible with both tunes while recording the road dyno info using PerfExpert. I exported the data from the app into Excel and then averaged the 3 runs with each tune.

Below are the results. A few notes. The vertical axis is road torque in ft-lbs. It's low compared to my car's actual performance because the road where I performed the WOT pulls is somewhat uphill. I wasn't looking for absolute numbers, but rather consistent data to compare the two VTEC crossover points. As you can see by the data, the tune with 6500 rpm crossover point produced more torque up to about 3300 rpm (sorry that the units for RPM are not more uniform), but from that point on the tune with VTEC set to 2500 rpm produced more road torque. I ended up using this info to lower my VTEC crossover to 3300 rpm as my main goal in tuning my car with Flashpro has been to increase low/mid end torque and horsepower. As Gernby has shown conclusively in the past, you really need at least a HFC or preferably a test pipe to significantly lower your VTEC crossover rpm or you will see a large drop in torque at the crossover point. You can see by combining the 6500 rpm VTEC curve below 3300 rpm with the 3000 rpm VTEC curve above 3300 rpm (essentially my new tune), that there is still a slight dip in torque from a peak of about 123 ft-lb at 3600 rpm to about 120 ft-lbs at 5000 rpm before the torque starts to climb again.

One big reason to get onto the high cam at lower rpm is that you can add quite a bit of extra timing (to produce more power) without risking engine knock. It was nice to see the results from my tests below actually confirm the Flashpro logic as a basis for setting the VTEC crossover point.

 

Good job, for me, it's probably easier and safer to get someone else to do the tuning.

 

very informative, when i had my 07 tuned (i/tp/e) my tuner had my crossover at 4200 rpm with at least 40% throttle.

 

AlSpeed2k - To each his/her own for sure. I learned an amazing amount through the process and I'm confident that my tune is safe.
Who ever tunes your car, I strongly recommend that you datalog and dyno it so you can know the results before and after and confirm the tune is safe.

ECaz34 - I think the crossover point is subjective depending on the driver and their goals. I wanted maximum low/mid range torque where I think this N/A engine is lacking somewhat.
My doing the test above I was able to know what that point was. Flashpro sets VTEC engagement based on intake pressure (above absolute vacuum), not throttle position. I have mine set as follows which allows me to adjust my WOT lambda low and tables in sync with the switch from low to high cam:

3300 rpm - .94 bars (nearly WOT)
5700 rpm - .884 bars (about 2/3 throttle)
6000 rpm - .742 bars (about 1/2 throttle)
7000 rpm - .2 bars (essentially zero throttle input)

Cheers!