Speedo = 4.33+26" ET Streets?

[12secSS]

According to my speedometer settings, the OEM setting is 7.71 (24.9" diameter/3.23 gears) ... tire/gear ratio. I am using a 12-bolt with 4.33 gears on 26x10.5x15 ET Streets. The new value should be 6.00, I then "Calculate for New Values" and go to "Save Changes", it goes to 6.15. Is that the limit? I was hoping to just have a rough program to drive this 'beast' this weekend to a dyno day we are hosting. We will be doing some 'adjustments' to get it ready for a track day.

I have already deleted all the references to the 4L60E and smog stuff. Thanks for your help!

[Chris@HPTuners]

please email your binary to me so i can understand the issue better.

Early code doesn't deal with real low diff ratio's very well (hence GM changed it in 2000). But i'm interested to see if that is the limit you are seeing.

Chris...

[Casey]

12secSS,

That is the limit if the numbering for the speedometer in the VCM code on the 98. Even then you are only 2.5% out of tolerance.


Ken

[12secSS]

Chris, I'll email it to you tonight. 8)

Ken, yeah I figured it was close enough. In fact it come out to 26.6" tires with those gears. My ET Streets should expand to that, or I can just use the 28" tire diameter when I switch over to 28x10.5x15 ET Streets. I also found a spare VCM from her old race car, it is out of a 1998 Camaro Z28 with a manual trans, don't know if it has programming or just doesn't work. I will try it out tonight as well. I will let you know. Thanks!

[12secSS]

Chris, sent you the bin file.