Do you recall what helix/ spring you have in your secondary? I am heading out this weekend to do some test/tuning and would like to have at least a couple spring options to try.Installed the STM secondary this afternoon. All I can say is wow. Long black marks on the road!! Wasn't shifting out at the right rpm's,all it took was one call to airdam told him what was going on, he had me make a few adjustments and now it's spot on. Really impressed with the secondary. Also installed new steering rack and some radius rods. It has been a full day. Tomorrow I have some new springs from Alex reed to install, hoping to soften it up a little.