4l60e speedometer way off

[Conner246]

Hello, sorry if this is in the wrong section. i am new to hptuners and am having a frustrating problem.

I have a 67 camaro with a corvette ls1 and ecu and a truck 4l60e. I did not have HPTuners at the time and sent my ecu off to get it tuned and vats removed. the computer is showing the correct tire size and gear ration, but the speedometer is way off and it shifts into 4th in about 15 feet.

I believe I have included my tune file, but if i did something wrong and you cant view the file please let me know. all help is greatly appreciated.

1967 camaro ls1.hpt

[aviat0r]

I had this happen when I first got my truck running. I had to adjust the vss setting under the "Speedo" tab.

[Russ K]

That's because the Corvette has a trans axle. And you can't change it in the tune, so you will need to have the PCM flashed with a compatible tune from a F Body or Truck.

A segment swap would work if you could find a matching OS. I looked a many of my tunes, and no matching OS's

Russ Kemp

[Conner246]

i am running drive by wire on this swap. if i get my computer flashed to a f body or truck tune will i lose my DBW?

when flashing the entire ecu can i use 09380120 and a 09386530 hardware number ecu or will that brick it?

my operating system is 12584929, does anyone have that same OS for a truck or fbody with a 4l60e?

[aviat0r]

63C10 0719.hpt

This is my tune. Its a 2000 vette drive by wire with a 4l60e.

[Conner246]

thanks, has this tune been segment swapped with a truck/fbody transmission tune, or is this a stock corvette transaxle tune?

[aviat0r]

I don't think it was swapped for the transmission, I was able to change the speedometer settings to get the mph to read correctly. Its been several years since I did it but I found the info on what to change on this forum.

[Erik Dicus]

far from a pro, but i would change the vss p/rev under hardware in the speedo section to 40.00 , and redo the math for gear ratio/tire size and pulses per mile. not to familiar with the gear tire wizard, maybe someone will chime in on it. but here is the math i used.

26.70 x 3.14 = 83.838 (rollout - distance traveled in one revolution of tire in inches)

divided by 12 = 6.9865 (converted to feet)

5280 divided by 6.9865 = 755.7432 (tire revolutions per mile)

755.7432 x 3.73 = 2818.9222 (output shaft revolutions per mile)

2818.9222 x 40 = 112756.8883 (vss pulse count per mile)