Problems with Racing Clutches I need HELP!


Nov 7, 2018
Kenner Louisiana USA
2008 335i Convertible
Need advice from people who HAVE EXPERIENCE with upgraded ZF transmissions. I had my 2008 ZF 6HP19 rebuilt with "Precision Raceworks" Kolene coated racing clutches and upgraded bushings. I also replaced the torque converter and installed a professionally re-manufactured ZF valve body with new solenoids, filter, seals etc. we used Pentosin ATF1 fluid since that is what P.R. said to use. My trans builder is also a good friend, he ONLY does transmissions at his shop, he is an expert of 20+ years.
My transmission slams hard into 1st from either N or downshifting from 2nd gear. I also get a "whirr" sound and slight delay between all gears up or down, especially 1-2, up or down. I have cleared adaptions several times. Did the whole BMW learning drive procedure. I started with stock software, then tried XHP stage 3 at the request of PR, then flashed back to stock, etc. it always has the same issues I described. PR says they have never heard of this. My trans builder says he thinks "racing clutches" was a mistake and even offered to build it back with stock ZF frictions if I just buy the parts. I am stuck and no one seems to know what is going on. Has anyone experienced this before? I will try to upload a video with the sounds.
Transmission sounds