Those with Superchargers and gears please come in

even with my 5liter's better torque curve i thought my vortech setup was a dog until 4k with 3.73's. i have the cobra sold and already picked up another 95, going NA for awhile but still have the s trim sitting in the garage :D
 
18 inch wheels have nothing to do with it, you will find 15 inch slicks that are taller than 18 inch wheel/tire setups. The dragster guys like a tall tire because they leave a bigger footprint than a smaller one, this increases traction.

http://reiderracing.com/rtech_tiredia.htm

http://reiderracing.com/rtech_engineRPM.htm

these will get you close, your results may vary.

like you said, taller 15 inch wheels. my new wheels are taller then the stock ones so does'nt that take a little bite out of the gears. is that why drag racers can use such low gears? because they have those huge tires. i'm asking not telling.
 
You can get a "short" 18 inch tire and get a "tall" 15 inch tire, the tire diameter effects the gear ratio more than people think. All these guys running 4.11s or such, I suspect, are running a taller tire, people like me (who are more handling oriented) are running "short "tires and 18 inch wheels to stiffen up the sidewalls for corners. The drag guys run a smaller rim, and a tall tire (large sidewall) this makes the tire flex more for straight line traction. On street cars they may not actually realize this (some do) but unless you drive your car to the extreme, you may not recognize the difference in tire diameter.
Don't get hung up on wheels size, it's the tire ( height)diameter which is most important.
Did you check those calculators I posted?
 
dude, get 3.73's man, trust me, you WILL NOT be dissapointed, i dont have a s/c on mine, but goddam i felt a difference on the take off with gears

+1 it'll get you into the powerband quicker and you'll wonder why the hell ford didn't give you these stock!. 3.73's should do fine and if you get on the highway you'll be glad you didn't go steeper!
 
Its overall diameter that effects gear ratio. Pull your car onto some level pavement, get out with a tape measure. Measure from the ground to the very top of your tire. Should be 26 inches tall. My 66 has 15 inch rims and the overall height is 26, just like my 04 GT with its 17 inch rims.

SOOOO if your overall height is still 26 then your gearing is unnefected, because ALL stock 99-04 mustang wheels are overall 26 inches tall, reguardless if it came with 15 inch rims (V6s) or 17 inch rims (GTs).