Won't converter slippage affect that? During lockup is the best way, 2.73s=80mph @ 2000rpms.

 

You have 2.73's.

Before my modifications to my engine and a tune, that's what my RPM/Speedo read.

 

for ******* real....screw all this RPM/speed/tire height guessing. Personally, I just put a little piece of tape on the bottom of the DS, rotate the wheel once and count how many times the DS turns over. If it goes over about 2 and 3/4ths times, then you have 2.73s

 

that vid sucks cause all the shakin around. jack up the back of the car and put a mark on the inside of the wheels that you can see and a mark on the driveshaft. get under the car and spin BOTH of the tires at the same speed and count how many revolutions your drive shaft makes for your tires making one revolution. you will have to have your car in neutral for this too and make sure its not on a hill of course cause you don't wanna get smashed. if your drive shaft turns 3 and a quarter times then you have 3.23's and if it turns 2 and 3 quarters of a turn then you have 2.73's. if it turns anything else then thats what gears you have. it really simple... no need to check tuning, tire size, speedo, or anything else.

 

i agree with the tape and driveshaft theory..but if you car is stock you can call the dealership and give them the vin number and they will tell you, or just look the code up on the door panel i beleive and it tells you all the options you have..(its on the inside of the drivers door, the sticker that also tells you the vehicle weight)

 

FWIW I checked 3 different cars with my GPS to see how accurate the speedometer is. The other 2 cars (speed) were were exactly what the GPS said. My 99 A4 T/A was off in increments of about 5 mph. For example, when my speedo said i was doing 35 but i was really doing 30. When my speedo said 70 i was really doing 59 and at 100 i was really doing about 84. Bone stock with factory spec tires.

My point is don't get to hung up on exact RPM quotes on here.