Went to order water softener from whole latte love - they're actually in stock! And at top of page they were advertising 'free flow profile with machine purchase', implying they have them in stock too.
Guy on phone was super nice, asked manager and was able to sell me the profitech e61 flow profiler for $200.
Arrived, nicely chromed, includes pressure valve and stronger spring.
Took about 30 minutes to install, 10 minutes of that was finding my plumbing tape to seal the pressure valve, 10 minutes was boiling the old assembly in cleaner.
Flow control knob replaces the top bolt on glicleur.
It looks exactly like the valve and flow adjuster on this profitech machine:Profitec Pro 500 PID Espresso Machine with Flow Control - Whole Latte Love
Ok. So first thing surprising is that pressure gauge shows something really close to brew pressure at puck. In my case thats 6.5-7 bar, even though my brewtus brew pressure shows 9.5. I tightened up my grind and was able to get the brew pressure higher but channelling became a problem and when it wasn't the coffee didn't taste good.
Is that weird that actual 'good' brew pressure is 6.5-7?
Been playing with it a few weeks now. Fallen into a local minima. I start with it fairly open, then when brew pressure rises to about 6.5 I start reducing flow until I see the brew pressure start to drop. Thats when flow is below what is wanted by the puck, I adjust flow up and down and sort of ride the shot until its fully extracted.
Coffee is different, more aggressive and brighter tasting, like it was brewed at higher temp - compared to a normal pull where I just leave flow wide open. Those shots are softer and generally have shorter pulls.
I'm glad I can try it, not sure its necessary. It does mean I can still make a passable shot even if I screw up the puck prep. Its a way to avoid channeling. I literally haven't had a sink shot since I started messing with it.