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View Full Version : VSS v RPM HELP



alz28
May 6th, 2008, 08:26 PM
4L60E SHIFTING @6200RPM WOT only in D, has shift kit TM & shift speed zeroed out to cancel adaptive learning.
upshifts set at 1-2 @31mph 2-3 @63mph 3-4@115mph
3.73 gears.
Race only car so 3-4 not used
have searched and looked at other tunes on Holden crazy.Nothing close.
question is (at last),
How do I work out the optimum shift MPH for 6200 revs? is there a formula using A4 ratios v rear gears v rpm. before I get to the track for reasons below.
The only log I have secretly managed( No computers in our race class) showed 1-2 shift 39mph@5679rpm??:confused:, 2-3 shift 80mph@6017. This was with shift points at 6000rpm Trap speed was 12.3@111mph at 5606 revs.
Any help would be appreciated
thanks
Al

Blacky
May 6th, 2008, 11:18 PM
I presume you're only interested in wide open throttle shifting at this stage?
If so, look at the Transmission calibration -> Shift at RPM -> Upshift values. You can specify at what RPM to initiate the shift.

If you want to work out what vehicle speed corresponds to what engine RPM in each gear, open one of the part throttle shift tables and click in a cell. The RPMs are displayed in the status bar at the bottom of the window. The values are calculated for each gear based on the calibrated gear ratios and diff ratio.

Regards
Paul

joecar
May 7th, 2008, 05:57 AM
Al,

Shift at the highest RPM your valvetrain and transmission can safely handle.

For the WOT shifts to trigger, the WOT MPH and WOT RPM both have to be met...
so set one a little lower, and make adjustments on the other until it shifts where you want.

Joe

jfpilla
May 7th, 2008, 03:31 PM
"Shift at the highest RPM your valvetrain and transmission can safely handle."
And if you know your peak power RPMs, shift 200 rpms above that, given what Joe said.
The attachment is a chart for 3.73 gear shift points vs mph.

alz28
May 7th, 2008, 06:35 PM
I presume you're only interested in wide open throttle shifting at this stage?
If so, look at the Transmission calibration -> Shift at RPM -> Upshift values. You can specify at what RPM to initiate the shift.

If you want to work out what vehicle speed corresponds to what engine RPM in each gear, open one of the part throttle shift tables and click in a cell. The RPMs are displayed in the status bar at the bottom of the window. The values are calculated for each gear based on the calibrated gear ratios and diff ratio.

Regards
Paul

Cheers everyone,:master::master:.
I take it I only need to adjust the WOT tables for mph not the part throttle tables aswell as the only time its at part throttle is in the pits before and after a run
Al

alz28
May 7th, 2008, 06:41 PM
"Shift at the highest RPM your valvetrain and transmission can safely handle."
And if you know your peak power RPMs, shift 200 rpms above that, given what Joe said.
The attachment is a chart for 3.73 gear shift points vs mph.

Thanks for file but for some reason my L/top says I don't have enough memory to open it even with everything else shut down?
I will email it home and try it there tonight