Found two other ways to adjust the 4-gear AT-box shifting points.
Govenor plastic adjustment screws:
on mine, it turned out to just be the govenor adjustment - 2 white plastic screws that we turned out 2 turns each. takes about 20 min to pull it out, 2 min to turn the screws, 20 min back. easy to do.
turning the screws 2 turns out on my old gal put the 1-2 shift consistantly at 6100, others are just above 6200/redline finally. the old gal rips now!! it's about 3mph faster (64mph) on my 600' driveway (and back to 0) yeehaa! can't wait to put it back on the track to see what that means in the 1/4mi
all shifts were higher, but 1-2 was noticably higher/now at redline from 4500-5400 before. other shifts at about 6200/a tad over redline but not enough to worry about on this motor, imo and it just seems faster overall as a result, but the track timers will tell the story better than my assometer
two screws are on the govenor body. it pulls out the side of the trans, and you can't miss'em - one on each side/white plastic.
I also did the trans bypass switch, but it only seems to affect shifting under part throttle (ie nicely drops down a gear when activated w/out any additional throttle input), and forces the trans into 1st while moving at low speeds w/no throttle input (impossible to do before).
I've also found some articles that indicated a low rpm shift (assuming everything is adjusted properly) could be from a dirty valve body circut or bad/spring or worn 1st gear clutch packs.
In fornt of the valvebody:http://avtopedia.ru/akpp/722-3%20722-4.pdf
Page 16. The arrow indicates the position of allen screw for full throttle control pressure. Turning clockwise results in earlier full load or kick-down upshifts. Turning counterclockwise results in later upsihfts.
I have seen both screws, but haven't touched them yet. Has anyone else used those before?
Some other related links and information:
More about WOT shifting issues and tuning: http://www.w124performance.com/docs/...pshift_RPM.pdf
More about modulator replacement and vacuum adjusting: http://www.benzworld.org/forums/w201...l-replace.html
Good S4 AT rebuild thread by atb:https://rennlist.com/forums/928-foru...ld-thread.html
About tranny pressures:
Hydraulic pressure controls Shifting.
-Hydraulic pressure is set by the primary pump and governor. This is NOT adjustable.
-Some pressure can be adjusted externally to control timing and quality.
-4 types of pressure work in concert:
a. Working Pressure: From the front driven primary pump, and its the basis of all pressures. Cannot be adjusted, but can be measured by a port.
b. Governor Pressure: Builds pressure with centrifugal force in a gradual proportion as the speed of the tranny increases. It works directly against control pressure to regulate the shift depending on vehicle speed. Cannot be adjusted, but can be measured by a port with the car driven a certain speeds.
c. Modulating Pressure: controls the working pressure, from partial to full throttle. Modulator can be adjusted to harden or soften the spring inside it. One way is constant, by turning the key inside it and the other way is constantly changing because is vacuum. This vacuum is also controlled by the VCV which leaks vacuum in proportion of the throttle position. Modulating pressure controls the shifts by varying the applied pressure to the bands on the clutches. Modulating pressure acts as a control for the working pressure in proportion to the torque of the engine. Can be adjusted by turning the key in the modulator and checking the pressure in the port close to it.
d. Control pressure: This is relative to the pedal position. Obtained from the modulator by means of the control pressure valve, which is influenced by the linkage or cable from the tranny to the accelerator linkage.
Their rants sound like a retarded jihadist braying medieval hokum, about as profound as explosive diarrhea but without its charm.