Can anyone tell me what RPM range I can expect with the following rear axle ratio's at say 60 MPH? 2.93 3.23 3.64 Thanks, Mark
here is a spread sheet i made ...its very accurate. the pop-up text boxes will help you decide which numbers to put in the squares. for the best results you might want to measure your tire from the center of the rear axle to the ground and double that number for your tire size (diameter)... tire sizes tend to vary quite a bit when trying to use the metric converting.... because "section width" can vary depending on the width of the wheel and a few other factors. plus rotsa ruk!! PM me if you have any Qs.
Yuk, I like the sheet with the info. on it. But, I can't get it unprotected so I can load tire sizes and other info. I asks for a password. Can I actually use this or is it read only? Thanks
Yuk , Very cool spreadsheet! :TU: John, put your tire diameter in the TOP open spot (with the red triangle) Then it'll work. :beer
in the "wheel size" box, if you put a number larger than 22, it will assume you are talking about overall diameter and then you can skip typing in the tire sizes .. a good book to get this type of info from is called "Auto Math" have about every formula you might ever want. i think you could take the "auto math" book and get a decent prediction on quarter mile ETs password is "zild"
RPM x Tire Diameter MPH = -------------------------- rear gear ratio x 336 That'll get you very close. example: 2400RPM x 26" tire = 62400 and 3.42 rear x 336 = 1149.12 62400 / 1149.12 = 54MPH
yep!!.... i created each of these sheets myself. excel comes with a few template sheets for things like store reciepts and stuff.... i dissected them to figure out some of the protocal and then used excel's help section for the rest. lots and lots of trial and error. i actually did the geardaddy part about 7 years ago. (my office 97 was new) my 74 lesabre vert has a 700r4 tranny (and the converter can stay locked up under full throttle) with a 2.72 rear gear and 235/75/15 inch tires ... throw that on the sheet and see how fast my car would be going if i were to twist the motor 3500 rpm in high gear ...:jd:
