Sounds like you have stock gears to me as well. To use the gear calculator, make sure you plug in the correct tire size you have on you rear tires, select the right transmission, and if a manual make sure you have the gear selected as 5th gear.

 

Stock gears. Why would you think a CAI & K&N isn't normal? Everybody and their mom has them on their V6 or V8 Mustangs.

If your differential cover isn't stock, you should give the car a good inspection for body work and other suspension work as little things like that are tell-tale signs it's been through the ringer once or twice.

 

k so then how come it dies down at like 90 mph tho?? like when it hits 4th or something..i mean it pulls but nothing like 0-90.

 

Because you have run out of gear. The 3.27's are dropping you out of your power range in the higher gears. Throw some 4.10's in there and it'll pull a little harder.

 

4th is a even ratio gear, not much power there unless its a 6 speed, then its gear differently and a bit higher.

 

are u an auto?

 

I think you were entering something wrong in that calculator, cuz it really does work. Make sure you have all of it correct, like your tranny and the gear specified and speed. With 4.10's, at 70-75 mph I'm at like 2500 rpm. I dunno if that means anything to you.

 

ya its auto

 

you have stock gears. i dont know what tranny you have so i posted both.

3.27 gears, with 245/45/17 tires
4R70W(wide 2.84)
At 85 MPH in 4th gear, your motor is turning at 2,546.6 RPM
4R70W(std 2.40)
At 85 MPH in 4th gear, your motor is turning at 2,437.5 RPM

 

k so then i have stock gears then all i gotta say is wow..this car is way faster then my 97gt lol. i cant imagine how much quicker it will be with gears. time to buy some!