so i was finally able to log line pressure. (it was quite an ordeal installing a sensor on the c5, but thats another story.)

i dont like what i see. the first pull (without shift) was done starting in d2 and shifting to d3 at 4-5k. shift point is set to 6400 and for some reason it didnt shift. iv seen that before reaching 6600+, but thats not the main worry. on the second pull trans shifted correctly, same shifting procedure (had to get off throttle almost hitting car in front of me). looking at the pressure trace its very inconsistent and above all there is a drop at around 5500 in both cases. ad2/violet/top. also the drop at 4650 to almost 15 psi on the second pull. pressure is maxed out in the tune starting at 300 nm, which seems to be working in the second pull, but not the first. (torque is reported incorrectly for some reason i never found out, ibpw and dyncylair give an idea of how it really is green/yellow/bottom).

short plateau in 1. pull is 200psi, the longer one in 2. pull is 175psi. before the pull (tp 9.8%) 67psi. 1. pull 152 psi at max rpm, then rises to 181, 2. pull shift at 157psi (max rpm), then rises to 215psi.

psi = 75 x (volts - 0.5).

edit: so is the pump spring too weak to produce more than 15psi above 5500? but then miraculously recovers? on the truck forums they say a 4l60e will not survive above 5500. well, it has the double spring, right? and the c5 shifts at 6000 stock. must be something else going on.

oh, and the trans is stock and is fed about 600 ft-lbs.

 

 

The first PULL imo would indicate the pan was evacuated once warm and expanded this did not happen. I can see no other possible way for the line to drop to 15psi during a pull and recover.

 

what do you figure might cause the drop after 5500 before the shift? it occurs in both pulls consistently,

its all a bit weird, because a 60% throttle 1-2 shift happens at 200psi (this graph). a 1-2-3 shift at 40% throttle happens at 140psi steady. (following graph). yes its at 160 kpa/710nm and at 110kpa/590nm, but torque signal is maxed out long before that. why could that be?

also, in 3. gear wot at 2500-3500 produces 200psi. max pressure overall is 215psi (during 2-3 shift, #1 post, 2. pull). however wot in 1. gear 3000 rpm only produces 150psi at 600nm reported. in the first graph of this post it seems to be at 205 psi in this area, despite the the wild swings.

so im trying to find out if the trans is dying or if the behaviour might be attributed to the workings of the ecu/tune.