I've been debating back and forth about a 7th injector system. A lot of us high-altitude guys don't really need it because we don't run as lean as the guys closer to sea level. That basically means I wouldn't get the same HP gains as they would from a 7th injector kit, making it less appealing at around $1000. At first I got A LOT of pinging, but now it seems that the ECU has been able to eliminate that ping except when it's really hot and the AC is on. Heat soak is the big thing I'm worried about now, since that causes the ECU to pull timing, which just kills horsepower and fuel economy at the same time. To solve that problem I've just purchased a progressive methanol injection kit. That should really effectively cool the air charge, which will give me more timing, therefore boosting horsepower and getting me back some fuel economy on the highway. Also methanol acts as a fuel so it will help me from running so lean under boost. The investment for that is about $350. If I don't see substantial gains I'm probably going to go with a 7th injector down the road.
As for the power, I recently ran to Zion for some canyoneering with my church priest's group (just me in the 4Runner), and I ran over Scipio pass in overdrive (not even unlocking the torque converter) pulling just under 80mph. It definitely needed to cool after that, and I burned a LOT of gas, but I was very impressed. I can run over point of the mountain holding 74mph all day long and it just doesn't mind. If I can keep the motor cool I think it will be a great performer. I love driving it now, and I keep bragging to my wife that I can beat her Volvo 2.5T (but I know I can't - 0-60 in 6.9sec is a little quicker than my superpig can go
) Keep in mind that I run 4.88 diffs so I'm basically stock in ratios too. If I went back to a 265/75/16 tire I'd probably be the quickest 4Runner around these parts, but I'd be racing the RPM's on the freeway.
Anyway, the supercharger has awakened the 4Runner. It's like driving it how it should have come from the factory, and I'm enjoying driving it again. Therefore worth the investment so far. Oh - my MPG's for this last tank were definitely better than they used to be for around town, so I'm not sure what to think about that yet. Freeway mileage has been a little worse, probably because I push it harder than I used to. If I keep the speeds low (79mph instead of 84-89mph)I'll get at least as good as without the SC. Go figure.