wwmost

ok guys i have 4:10 gears. i have a dallas speedcal in that fixed my speedo but then i installed my mph tune off of my sct and it is off by 15 mph. i think tim tuned my car for my 4:10 gears but i alrready fixed it. does that sound right cuz its off by 15. i think i just might take off the dallas speedcal and see what that does. soo does 4:10's on a unfixed speedo off by 15? if soo im just gonna take off the speecal. im sure it was my fault for not telling tim[:@]

sprostang

Yeah, I would take off the speed cal. You need to use one or the other, not both. I`ll bet without the speed cal you`ll be ok.

wwmost

well if the tune i got doesnt have the speedo adjusted ill keep the speedcal in there and just adjust the speedcal. does anyone know the stock rear end ratio on a 04 gt coupe 5 speed? ill mess with it tonight and see if i can fix it.

sprostang

Its a 3.27 stock

03sonicgt

I have the same problem, I need to take off the speedcal from the previous owner. Where are the speedcal's located at??

01BlueCobraVert

The speedcal plugs in down by the trans. I am not exactly sure where but it is by the trans.