Apologize for not posting last night, but it looks like the turbocharged FR-S is much better at taking a 7 day road trip than I am.
As you all know, we spent another 2400+ miles driving to California and back for Formula Drift at Long Beach. I took this time to test the AVO Turbokit on 91 octane gas while driving from one end of California to the other. Now, this wasn’t the first time we had tested the car on 91, but those initial tests were done on our 5psi base kit with stock exhaust. This time we wanted to test our Stage 2 setup, on the base 7psi and also at higher psi levels.
To clarify some details, this was with about 500-600lbs of event gear in the car, so it was under a bit more load than normal for most. I also got gas from a bunch of random gas stations without using any octane boosters or any other additives.
Overall, it didn’t do too bad. I started at 8.5psi, and had to bring the car down to 7.5psi when I hit a gas station that had bad gas. And that’s going to be a fact of life for people living in the 91 octane desert, there’s good and there’s bad gas stations down there, and it’s going to make all the difference in the world.
The first log shows what the car was doing on a blend of 91 octane and 92 octane, at 8.5psi. As you can see, it was perfectly happy even with that blend of about 7 gallons of 92 and the rest 91. No issues, no fuss, smooth power delivery.
The second log, well – that’s the good log of pure 91 octane, at 7 psi. Cruising on the freeway, plenty of air over the intercooler, in 80 degree temperatures. There was one knock event. The interesting parts is that the Ignition Advance Multiplier is all over the place even when it’s not knocking. This is the ECU doing a fine job of keeping it from knocking – every time it anticipates it’s going to knock, it was pulling the IAM back to keep it from knocking. Every time it thinks things are going ok, it’s putting the timing back in.
On bad gas, it was worse, with the timing being pulled back even further. That is what it’s supposed to do, so everything was safe. It does show that there will be limits to the boost/power levels you can run on 91 octane, and other factors, such as ambient temperatures, stop and go traffic, etc., will have their effect on performance. Keep in mind that it’s even doing that in n/a form, so the real moral of this story is that 91 octane is evil.