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leres
February 24th, 2005, 06:32 PM
The speedometer parameters page doesn't work the way I would expect; it seems likely it's somewhat broken. (Am I really the first to program a gear ratio change?)

I've got a 2000 SS with a manual transmission; I went from 3.42 to 3.73 gears. The stock VSS config is 17 pulses/rev, 2766 ratio and 47015 pulses/mile. If I enter 3.73 and click on update, the ratio changes to 3016, pulses/mile goes to 51277 and the adjustment percentage goes to -9.06%. Good so far.

Now I press "save" expecting it to update the changed parameters (VSS pulses/mile and diff ratio). It changes the diff ratio to 3.73 (ok) but the only other parameter that gets updated is the vehicle speed sensor ratio which changes from 805.1953 to 805.0000. I'm not expecting that to change (isn't it independent of the rear end ratio?) The vehicle speed sensor pulses per mile parameter stays at 47018. Even more bizare, back in the VSS configuration window, pulses/mile have changed back to 47018 and ratio has changed to from 3016 to 805. (What is ratio supposed to be in that window anyway?) If I click on update again, the values go back to what the were the first time I clicked update with 3.73 as my new ratio.

The get around this I manually entered 51277 as VSS pulses/mile (and reset VSS ratio to 805.1953). However I notice if I save the config and exit and open it again, the value has morphed to 51276.

One other question, is the maximum vehicle speed range really 0-256? I always figured it was stored in a byte so it would be 0-255. I was tempted to set it to 256 and see if it wraps to zero but I didn't have time...

Blacky
February 24th, 2005, 10:01 PM
The speedometer parameters page doesn't work the way I would expect; it seems likely it's somewhat broken. (Am I really the first to program a gear ratio change?)

You're not the first, a few other reports have come in about the speedo calculator. It is being fixed.


One other question, is the maximum vehicle speed range really 0-256? I always figured it was stored in a byte so it would be 0-255. I was tempted to set it to 256 and see if it wraps to zero but I didn't have time...
It is stored in a byte and that makes the range 0-255 (maybe its 1-256 instead) I'll check. Anyway,as you say 0-256 is not possible.

Regards
Paul

Blacky
March 13th, 2005, 02:55 PM
One other question, is the maximum vehicle speed range really 0-256? I always figured it was stored in a byte so it would be 0-255. I was tempted to set it to 256 and see if it wraps to zero but I didn't have time...
It is stored in a byte and that makes the range 0-255 (maybe its 1-256 instead) I'll check. Anyway,as you say 0-256 is not possible.

Actually I was wrong, it is stored as a 16 bit value and the scale is set so that it really is 0..256 - go figure!
How anyone is going to test if the limit is 255 or 256 I do not know - but if someone has a spare proving ground and a really fast LS1 then let me know :)

Regards
Paul

highperf
March 23rd, 2005, 01:36 PM
So is there then a confirmed issue with setting new ratio values ? I need to update for my newly installed 3.46 to 3.91 upgrade in my LS1 Pontiac GTO and I haven't been able to bring myself to do it, because I am not comfortable with how the Tune software acts when I enter those values.

It just doesn't seem right.

I may be a bit paranoid here due to nothing more than my lack of knowledge.

Should I avoid updating the ratios since a fix is needed?

Blacky
March 23rd, 2005, 01:53 PM
So is there then a confirmed issue with setting new ratio values ? I need to update for my newly installed 3.46 to 3.91 upgrade in my LS1 Pontiac GTO and I haven't been able to bring myself to do it, because I am not comfortable with how the Tune software acts when I enter those values.

It just doesn't seem right.

I may be a bit paranoid here due to nothing more than my lack of knowledge.

Should I avoid updating the ratios since a fix is needed?

Yes, wait until we release the next version.
I just tried your diff change in the new software and these are the results I got: (the current numbers may be different than yours, however, if they are the same then you can use the "new" values below).

Current tire size: 24.72
Current ppm: 47992
Current diff 3.46
Current TOS Revs/mile 2448.5747 (aka Speed sensor ratio)

New tire size: 24.72
New ppm: 54235
New diff 3.91
New TOS Revs/mile 2767.06 (aka Speed sensor ratio)
Adjust shift speeds by -11.51%

Paul

highperf
March 24th, 2005, 07:12 AM
Thanks I knew it didn't seem right. I came up to post the question and seen this thread.

The update comin soon ? It's still snowing up here and I just took my car off of blocks, so I have some time to wait. But not too much.

Jim

Blacky
March 24th, 2005, 07:49 AM
Thanks I knew it didn't seem right. I came up to post the question and seen this thread.

The update comin soon ? It's still snowing up here and I just took my car off of blocks, so I have some time to wait. But not too much.

Jim

The latest 7.1.9 update has just been released for final beta testing (about an hour ago :) ). Assuming no major flaws are discovered, we hope to release the public version by end of March.

Regards
Paul