Originally Posted by 2ZORNOT2Z

That's where most of us 2019 Z owners are tapping out without meth or a cam. The beauty of the flex fuel sensor is you can just keep adding E85 until you start to see fuel pressure drop and that's likely to be 685-700 depending on the tuner's abilities. I did an expansion tank (CPR) to deal with the heat of the 2.3 pulley on the stock blower along with 2" LTs, 5" CAI (CPR), and DSX flexfuel sensor. I'm tapped out at E35 at 685/711. It's a fun street car which is where I use it 90% of the time and the expansion tank does a good job of keeping the coolant temp under 200 during spirited driving around town. On the track I don't add ice, just give it 10 minutes with the hood open and coolant temps stay under 230 over 7-8 runs. Works for me, ymmv. The maggie will have better street manners when launching from a light or the like but the 1740 will give you more torque which typically nets better times at the drag strip when prepped with DRs out back. I'd love to have the 2650 just couldn't justify the extra cost, it would have doubled what I spent for the same power output. If I ever go SPI that's when I'd add the 2650 and shoot for 850+ rwhp but I'll likely never drop another $20k on this car. There's only so much power you can use on the street and my car's about perfect there. Next thing you'll have to deal with is traction, lol...

Originally Posted by 2ZORNOT2Z

I think you are right about the 2650 down low but that thing will scream on the big end! I love the flex sensor, it's by far the best bang for the buck mod on the LT1 or LT4 imho and I don't mind mixing to E33ish to get an extra 35 rwhp boost over pump 93 either (in the spring/summer/fall). E85 here in the midwest is more like E55-60 in the winter and they blend it with pretty low octane gas. It's kind of junk in the winter. It's E72ish in the summer which is better. I don't drive it as much in the winter with snow/ice like we have on the ground right now (12 degrees outside to boot, wish I was in FL!). The colder temps mean I swap to my A/S3+ tires so I can keep driving it but those can't hold all 711 ft-lbs of torque so running pump 93 makes it a little easier to drive and I avoid any issues with water from the ethanol in the tank if it has to sit for a week. In the summer I swap to the R888R front and NT555R2 in the rear and it's a blast to drive.