View Full Version : gear ratio and tire height ?'s

09-26-2011, 11:27 AM
ok its kind of a calculation question but i figured id get some more opinions. lets say i have a 275 width drag radial on a stock fbody wheel thats 28 inches tall. with a rear gear ratio of 3.73.

would that be too much tire to make a full 1/4 mile pass and go through the traps at the top of 3rd in a 4l60e(5800-6000) with say a bolt on car with nitrous. or should i go to a 27in or 26in tall tire. im tryn to get away with goin out the back door at just the right spot. and i wanna get the tire choice down on the first try. im just not wanting to run out of gear on the bottle at the big end

09-26-2011, 12:19 PM
Here is my excel spreadsheet calcs

Tire Height, Rear Gear, 4L60E 3rd Gear, 5800 RPM, 5800 RPM, 6000 RPM
28" Tire OD, 3.73:1, 1.0:1, 129.5 MPH, 131.8 MPH, 134.0 MPH
27" Tire OD, 3.73:1, 1.0:1, 124.9 MPH, 127.1 MPH, 129.2 MPH
26" Tire OD, 3.73:1, 1.0:1, 120.3 MPH, 122.3 MPH, 124.4 MPH

09-26-2011, 12:26 PM
so a 28in tire would give me the most wiggle room on the big end? i figure right now it might be a 120 car if its lucky on 100 shot and idk what it would do after it gets a stall and the pills get upped.

what would be the suggestion for a 4l60e fbody with a 3.73 gear, stock suspension, and a 100 shot out of the hole? its been 109-110 n/a

09-26-2011, 12:28 PM
Personally, I like to have room to grow so I would go with the 28" but I think I am in the minority on that one... Most people like to cross the line at the top of 3rd, auto, and 4th manual.

09-26-2011, 02:08 PM
i want to go through the traps at the top of 3rd but i dont wanna screw myself when i up the pills or something and have 5 passes on 26's and then need 28s when i do something else. itll be a mostly street raced car so i suppose i may go with the 28's. i know ill have to roll the fenders but can you fit a 275 28in tire on a stock fbody 16 or should i just buy some summit stars or something