If this TIRE/GEARING/MPH/RPM chart is helpful, you're welcome to use it. It was originally created by Rich Gordon, and I've subsequently made some small improvements.
https://tinyurl.com/AlpineSpeedCalculatorEXCEL
NOTE: This spreadsheet MUST be opened in Microsoft Excel. IT WILL NOT WORK in Google Sheets, because it takes advantage of several of MS Excel's capabilities that Google doesn't have.
You must download it, then open it in Excel, if you want to use it.
When you click on the above link, it will open it in Google Sheets, but it will be garbage - none of the buttons will be visible. Next, to download it in a usable form:
- In the Google Sheets menu bar, click "FILE" ==> "DOWNLOAD" ==> "MICROSOFT EXCEL (XLSX)"
- This will download the spreadsheet to your computer, where you can then open it in Excel.
Instructions for use:
- ONLY ENTER DATA IN THE LIGHT BLUE FIELDS
- NO NOT ALTER ANY OF THE RED FIELDS (they contain all the calculations and variables)
- You can use the Rear Axle Ratio buttons to choose from the common rear axle ratios
- You can use the Overdrive buttons to include or not include overdrive
- You can use the Wheel Diameter buttons to choose from 13, 14 and 15" diameter wheels
- You should enter in the Tire Width field your choice of width
- You should enter in the Tire Height field your choice of height
- You can then use the chart to see what speeds the engine should be doing (RPM) at any given speed
- You can also see your car's potential top speed (the red-line at the top of the chart is the maximum RPMs for a stock Alpine motor)
