Over the past few years I have been researching LS swaps for more power and economy but was never satisfied with long term reliability of GM engines and the many quarks that come with an engine swap. I have decided I will stay with the 1FZ and look what I can do to make it a more enjoyable driver. When I first got my LC I did a basic tune up and advanced the base timing between 3 to 5 deg but didn't really see any improvement in power. I swapped out the factory cats for high flow Magnaflow cats and got a small increase. Fast forward to 2023, I decided to explore the affects of different fuels in the LC. I went straight to 93 octane non ethanol and after a full tank noticed a huge increase in power. Mostly in the bottom end, I went from pulling hills in 2nd or 3rd to 3rd and 4th. Mileage also increased from 12.5 to about 14 mpg. I dropped down to 91 octane non ethanol and lost just a little power but not significant. This is just seat of the pants driving but I went from 0-55 mph between my driveway and my daughters on 87 octane to 0-65 mph running 93 octane. This is on 35" mud tires with the factory 4.11 gears. Daily driving is a pleasure now but I always want more power. I did try switching back to 87 octane and almost immediately lost my power gains. I went back to struggling to maintain 75 mph on the interstate while going up hills. I plan on upgrading to 4.88 gears and after a rebuild adding a turbo kit with water cooled intercooler. Through all of this I have discovered the 1FZ likes timing to make power, however the EFI system with knock sensors will pull timing like mad to protect it. Which is probably why the superchargers made little extra power. I would recommend anyone running a supercharger or turbo to add a air to water intercooler.
