How about a transmission tuning tutorial!

[joecar]

He insisted on the Allison Transynd. But said Amsoil's, "New AMSOIL Torque-Drive Synthetic ATF Provides Excellent Protection for Allison® Transmissions", was good too. Since he warrantees the trans for a year and GM doesn't care anymore it's easy. I thought you would be interested.

Yes, that is interesting, thanks.

[joecar]

GM.TRQENG allows you to link from scan log to tune table so you can see where on the pressure tables you're at.

[ringram]

Ok, so I forgot you can attach files to posts now..
Anyway here is the magic document with most of the info from this thread.

Ill add in Joecar's shift pressure pics and update the doco in the next few days. In the meantime, go and break traction with this doc.

[Jphdg]

Thanks again guys, Appreciate the advice and comments. I shell grab that PDF and have a read and will see how things go this weekend.

[oztracktuning]

I have a stock transmission with Transmax Z and im using a Yank SS3600 converter.

I want to setup just a drag transmission tune.
At present im considering just going the full hog
Full line pressure 662Kpa 96psi
zero shift times
no torque management

I have been racing it often at about 0.2-0.3
and 91psi

I assume at 11.781 with 1.61 60 footer i am making the top of the table
so i have the last 4 cells in the tran pressure table set to the highest pressure

[jfpilla]

WOT trans pressure is set at the factory for A4's. It can only be changed mechanically. When you change pressure you are changing part throttle pressure only.

[oztracktuning]

My TRQENG is lucky if its 283Nm near my change points - taken during a log in 11.768 run.

[joecar]

See this diagram (scroll down to Common Hydraulic Functions): showpost.php?p=21221&postcount=5


It shows that the PCS solenoid does not directly control "Line" pressure, but rather it regulates "Torque Signal" pressure [from AFL pressure] which assists the Pressure Regulator valve via the Boost valve/spring (see items 1a, 1b, 1c).

(the AFL valve/sping limits the pressure going into the PCS solenoid to a max of 96-100 psi)

So PCS pressure in the range 0-96 psi indirectly controls Line pressure in the range 50-230 psi.

The PCS solenoid has a calibration screw in the back of it;
turning this screw in 1/8 turn will firm everything up quite a bit, so if you do this watch out,
use a pressure gauge on the Line tap (side of case above shift linkage) to monitor Line pressure.

A more correct name for PCS/TFM pressure is "Torque Signal pressure".

[joecar]

My TRQENG is lucky if its 283Nm near my change points - taken during a log in 11.768 run.

In the pressure tables, make sure you're at 90+ psi starting from well below 283Nm/208fllb.

208ftlb, that's real low, should be getting 350+ftlb, did I convert that correctly...?

What is your GM.DYNAIR like (does it climb to 300+g/s as RPM climbs during WOT)...?

What do your VE and spark tables look like...?

If you have a log showing the following pids please post a pic:
SAE.VSS
SAE.RPM
SAE.TP
SAE.MAP
SAE.MAF
SAE.ECT
SAE.IAT
GM.DYNAIR
GM.TFT
GM.GEAR
GM.TCCMODE
GM.SHIFTLAST
GM.SHIFTDELAY
GM.TFMPRS
GM.TRQENG

Is traction control kicking in...?
Is B1901 is set too low...?

[oztracktuning]

The GMTRQ is weirdly low it seems.
my g/cylinder looks normal and my VE table is set to give 330g/s or so at WOT at full rpm. Timing is giving 28.5 deg. In the middle of the gear in logs the highest GMTRQ i see is 319Nm which is still miles too low.