corvettekyle

New to me 2004 e55 but has the 580 revision blower, I am experiencing what feels like the car falls flat on it's face for a split second inbetween the 2-3 shift, feels like I'm lifting the throttle to shift a manual, I have been doing a lot of reading and most things that I came across said this is characteristic of the clutched pulley, the "rubber band effect" , but I am not sure this is what I am experiencing as it only seems to happen during the shift right around 1200/1500 rpm. If I give it any more throttle it does not do this, and seems to be much more prominent in comfort mode rather than sport. It is barely noticeable at all in manual mode. I went in and did the "sneaky" ECU reset to reset the trans adaptive learning and after I did that it drove fantastic, but only for two days! It seems that once the trans learning set in again it comes back. I have no trouble codes, trans fluid is filled properly.

During normal operation does the SC pulley disengage inbetween shifts if all other engagement parameters are met?

Is there a way to disable the trans learning? Could this be indicative of a conductor plate? Or if not would this be fixed with an upgraded valve body with higher line pressure?

Thanks,

Sulaco

Sounds like normal S/C engagement to me. I spent the first month with my E55 thinking it was broken, had a bad tune, etc. It's just the nature of the clutched pulley.

SICAMG

No it will not disengage the clutch on the shift for any gear until the engine is returned to idle.
Take the supercharger belt off and take it for a ride and check it again.

GinDistiller

If you can, watch or log your timing and TPS values.

Stock throttle body?

I've spent a lot of time chasing a similar issue, and as far as mine is going it's 'complicated'. The SC engagement is really only felt right after starting, which could time with a first shift but SICAMG is right, it does not disengage the clutch until you come to a stop again. I had an issue with the SC bypass valve, it finally coded and I replaced it and things improved. In the case of my '03 (also w/ 580 blower and a few other things), my current issue is with timing and knock correction. Found my timing being pulled back a ton, and intermittently, and that knock control was engaging. Go into STAR and test the sensors and they are dead, barely if no response at all to throttle stab under the self test.

I'm pulling the SC and putting two new ones in next week, I'll report back on changes!

And, if you're looking at trans values, see if you can get hooked up to STAR and see fill times etc in the adaptation menu, if all of that looks good it's not worth spending time and money on things like valve bodies etc. And there is no way to remove adaptive trans control, I've got a tuned TCU which improved shifts but it still has the same learning characteristics as stock.