5 ÷ 4.11 = 1.219
1.219 x 6800 = 8,292
This would be true with a manual trans as long as the clutch wasn't slipping. The problem with the OP setup is that it appears that his torque converter is slipping a ton at the 1/8 mile mark. As far as we can tell from the numbers he posted, his driveshaft is turning about 4400 rpm while his engine is turning 6700 rpm. Could be a bad converter, could be the wrong gears, could be something else.
My goal was to accelerate out of the launch harder or faster. If that was to give up a little MPH at the 1/8 I was ok with it. I’m confused some on the converter slipping a “ton”. I told BTE/abruzzi what they flash at, what I shift at and what RPM is at the 1/8 and they both run about the same/setup similar.
The car will accelerate out of the hole harder as long as you have traction. You have huge rear tires so I assume you have plenty of traction but I guess you'll find out. A simple data logger would answer a lot of your questions but if you don't have access to one you can get a lot sorted out by just using simple math. The math right now shows your converter is slipping about 35% at the 1/8 mark. That isn't a huge surprise if the car is still accelerating hard at that point. Cars set up for the 1/4 mile are often slipping the converter a bunch at the 1/8 mile, especially if they have just shifted into high gear.
How fast should your car go in the 1/8th based on weight and power? That number should be your "guide". Once you know that number you can figure out what your gear ratio should be. It really helps if you know what the power curves for your engine are. If you don't have any dyno data then you have to work off how the car feels. Is the car laying over at 6700 rpm or is it still pulling?
When do you pull into high gear? Pretty close to the finish line or halfway down the track? With the 5.0 gears you might be pulling into high gear pretty soon after you leave the line.
