Speedo Calculator for TunerPro

[yoheer]

Thanks for the reply. Im gonna swap my rear end with 3.42.
Do I need to modify some other tables, like trans shifting or just speedometer and that's it?

[NomakeWan]

You will likely have to change those tables too if you have a 4L60E, yes. Basically, first you need to convert the speeds listed in your shift points into RPMs by using the stock wheels/tires/ratio as a guide. Then you'll know when the stock car is going to engage the shifts. Then change the ratio (and wheels/tires if necessary) and convert those RPMs back to speed. Then fill the speeds back in.

Or decide what RPM you want the shift to be at, then convert that RPM to a speed with your new ratio (and wheels/tires) if you just want to ignore the stock settings and do your own thing.

[yoheer]

Maybe it would be easier just to compare with stock bin from 3.42 4l60e f-body. But I cant find it :(

[NomakeWan]

Because it may not exist. But you can use the B-Body auto 3.42 as a reference for the same tables if you want.

[yoheer]

I thought about it. And I think that b-body tables are for "calm" driving, not so agressive like vettes or f-body.
What I found else
3.42 manual tranny tables are almost the same with 2.72 automatic.
But 3.23 table shifts on much lower speeds. It seems to be from 3.4 f-body.

[NomakeWan]

Sounds like you should just do your own math, then. ;)

[steveo]

why not just fix your speedometer calibration but use the transmission tables for a 3.23 f-body. they will be pretty close and then you can adjust from there. the stock shift points aren't great anyway, you'll want to change them.

3.42 manual tranny tables are almost the same with 2.72 automatic.

since the transmission tables in a manual bin aren't used, they probably just left them incorrect