So, I'm having a little trouble with the engine tabs on the spreadsheet. I have a dyno chart for my engine (essentially a Toyota 2JZ 3.0L motor) which gives me HP and Torque vs. RPM. I know what transmission I'm putting in and have the ratios. I know what my rear end ratio is. I know what tire I'm targeting. But I'll be damned if I can figure out what to put in any of these boxes. Let's ignore all the crazy mixture and turbo stuff for now. Here's the current version of my spreadsheet: https://www.dropbox.com/s/xdtt8ro7gbhf84v/rF2-Physics-Calculator-jzz30-V0.33-v0.4-180630.ods?dl=0 Dyno chart: https://www.dropbox.com/s/9fozumdfbkq5gfh/sc300-dyno-rpm.jpg?dl=0 Gear ratios: 2.66, 1.78, 1.30, 1:1, .80, .62 Final drive: 4.08 Tire: https://www.maxxis.com/catalog/tire-450-107-victra-rc-1 (275/35R18) Looking at the Studio 397 spreadsheet the speed-in-gear seems all jacked up. Here's a speed-in-gear chart: https://docs.google.com/spreadsheets/d/1Ow-ruaHPm8TvzEthwMJKfgtS8847rJlL_YXCUBehshI/edit?usp=sharing Here are the values from the spreadsheet: 92.15 137.61 189.88 245.73 307.16 393.16 I am thinking that my issue is all in the final drive. I'm trying to understand the "bevel" times "combined". Or perhaps those values are in metric. But they are basically 2x what the Google spreadsheet indicates I should expect. I can't believe this factor of 2 for everything is magic, and 1KPH is 0.62 MPH, so that's not it. Any thoughts here?