Finally managed to arrange a time to get my BRZ back on the dyno to verify the gains from the Billet Power Blocks. This is my exact same car on the same dyno, same operator, same fuel (Shell V-Power Nitro+ 93 octane) but about 7 months apart.
If anything, the conditions for my baseline run back in February 2022 were better - about 5 degrees C / 9 degrees F cooler, with similar humidity, though the differing Dynojet correction factors (0.95 back then vs. 0.97 today) should account for that.
Run 1 is my stock baseline from February, Run 2 was with the BPB's and some cam timing changes I was messing around with, and Run 3 was stock tune with the BPB's.
Disappointingly, but not totally unexpected, the cam timing changes resulted in a slight loss of power and torque vs. the stock tune on the BPB's. These were the recommended timing changes from using the VGI tool, so not sure what happened there. I most likely screwed something up, but who knows. Playing around with the tune is just a "fun" thing for me to do without spending more money. My plan is eventually to have it professionally tuned once I have the ACE headers installed next year.
All that to say, Run 2 was removed from the image below (updated from my original post on 2022.12.02), and I'm back to running the stock tune for now...LOL.
So, without further ado:
Notes on Run 3 (BPB's on stock tune) vs. Run 1 (stock baseline)
I was surprised to see a peak HP and torque gain, as I mostly just expected the power band to be shifted lower in the rpm range, but on the stock tune with the only modification being the power blocks,
we saw peak vs. peak gains of 3.9 hp and 8.9 lb.ft. of torque!
More importantly, there were gains EVERYWHERE other than from about 6,800 rpm on up. There is literally nowhere it makes less power than stock except in that last 400 rpm.
- Right from the beginning of the pulls to just past 3,000 rpm there is a substantial gain, with an initial torque peak around 140 lb.ft. @ 3,000 rpm vs. the old peak of 133.5 lb.ft. @ 3,210, so gains of about 6.5 lb.ft. down low.
- The torque dip is substantially shortened, with a big surge in torque coming in from just past 4,000 rpm to about 4,300 rpm (which is DEFINITELY noticeable from the driver's seat). This is where the greatest gains are had vs. stock with about a 14 lb.ft. gain vs. the same rpm.
It also correlates with a definite resonance effect around that RPM that makes the heat shields on the stock header buzz slightly. I'm looking forward to seeing how the ACE headers fill in the dip further (and the buzz disappearing without the heat shields). 
- From 5,000 rpm to the new torque peak at 6,250 rpm, there are gains of about 6 - 10 lb.ft. of torque.
Again, there is more torque and power EVERYWHERE except at the very top end of the rev range with the simple addition of the Billet Power Blocks. I would HIGHLY recommend them to anyone on a 1st gen BRZ/FRS/86 staying NA, and especially if you're staying otherwise stock.
Future Plans
I have my ceramic-coated ACE A350 headers waiting to be installed sometime next spring. I'm interested in exploring the common belief (myth?) that the BPB's are "worthless" once you have headers on, since I can't see a logical reason that would be the case.
My plan, I think, will be:
- Have the car dyno tuned as-is (with just the BPB's) so that I have a properly tuned number for that
- Install the headers and dyno the combination on the stock tune, the BPB tune, and another custom dyno tune for the combination
- Remove the BPB's and do another run without them with the final tune to see if there's a noticeable difference in power without them installed.
That's going to be a fair bit of money spent on dyno tuning / runs, but I'd really like to answer that question / debate once and for all.
While I wait to be in the financial position to do that and the other work I want to do on the car, I might play around a bit with adding some timing advance up top to see if that can gain back some of the power lost from 6,800 onwards, since that was noted by Shiv from OFT as being a good idea.