I have tuner cat and just installed 4.10's in my 95 z28 with a 6 spd. As many of you know tuner cats speedo calculator is never right. I don't have access to a GPS anymore and was wondering if anyone could help me with the right numbers to put into tuner cat. I don't know if LT1 edit has the same fields or not.
My car has 275/35/18's with 4.10's and 6 speed the values are.

Speedo scalar- 14
Speedo scalar fraction- .986
Speedo scalar scantool- 55.692
time between pulses for stop- 63.374
Pulses per driveshaft revolution- 17

I'm hoping LT1 edit or something has these same fields and you can tell me what it calculates. I remember when I had 3.90's, I had to use a GPS and keep modifying the values until I got the speedo accurate. I just don't have the GPS anymore.

 

makes you feel any better, ever since i got my 4.10s put in at 40, my speedo said 44/45 prob wasted 100 miles on the clock so far bc of this

 

I tried.... your right, TUnercat does not appear to make any sense reading a correctly reading a working LT1_Edit File.

What I did:
1) In LT1_Edit... entered your info (275/35/18's with 4.10's) my file is a six speed tune working great with Nitto 315/35/17's, settings match my setup.
2) Set your parameters in LT1_Edit
3) OPened in TunerCat

I see this in the Speedo Cal section:
Tire Size: 285/40/17
Gear Info: Rear End Ratio: 3.07:1

Sensor: Stock
Car Type: Y ????????
Trans Type: Auto????????????


New Cal Values:
Speedo SCalar: 25
Speedo Scalar Function: 1.015
Speedo Scalar Scantool: 41.036
Time Between Pulses for Stop: 36.554
Pulses Per Driveshaft Rev: 40

Current Cal Values:
Speedo SCalar: 14
Speedo Scalar Function: 1.014
Speedo Scalar Scantool: 55.109
Time Between Pulses for Stop: 64.27
Pulses Per Driveshaft Rev: 17

 

Makes perfect sense since none of that stuff is stored in the bin file.