I know that this is an old thread , but I wanted to add my 2 cents. I recently purchased a DV+ for the N18 automatic used from a forum member here. He sent it to me along with a factory diverter for the solenoid. I was having some issues with the factory DV, even with the Alta spring, and I wanted to get it squared away before my ECU tune.
After installing it, I started getting a code that the diverter valve was stuck closed... well rev the motor and clear the code and it would go away for a while but kept recurring. I emailed GFB about it, and I do have to say, fully admitting that I bought it used, they were still very helpful in their response. I lubed the piston on install as per the instructions, but it was sticking or something. So as a last resort before switching back to the factory DV, i uninstalled it and re-lubed the piston, replaced the vacuum hoses with better quality ones and switched the DV solenoid to one I know for a fact works (never tested the other one, I know, dumb) I also relocated the solenoid half to a different spot (in the instructions they tell you to put it in a specific spot...but in their install video, they show a slightly different location to mount it, it’s much better IMO). After putting it all back together, it has been working flawlessly! It really does hold boost better between shifts. It works great with the increase in boost from the tune. My only complaint about it.......... is the noise! As in there isn’t any! Lol! It’s so much quieter than even the stock diverter that even with a cone air filter, it’s almost silent. So quiet in fact, that I removed the cone and put the factory airbox back in since my intake temps are about ten degrees lower with it on. High flow panel filter works really well for airflow on the R60 with the factory airbox. All in all, I am very pleased with the function of the DV+ if not the volume, lol. As much as I do love that pshhh sound, the performance gain far outweighed the sweet noise IMO. Cheers!