Tire Rack says to run the presssure noted on the B pillar on my 235/35 19s - are they correct?
 

They said the size of the tire has nothing to do with the recommended pressure, so the 235/40 18 pressure spec should be used.

I run 37lbs

That's a good baseline, just check your wear pattern to adjust +/-.
 

Different tire constructions use differing amounts of pressure as structural support, and different drivers will get differing wear based upon driving techniques/traits.

That sounds low for a 19" wheel,...anyone want to chime in on this?
 

I would have thought 42psi front and 40psi rear minimal. Its a good question. I also would like some real world feedback on this topic.

Per KurtW...yes. After attending a few HPDE's over the last year, the biggest mistake is.....
 

cold tire pressures starting much too HIGH....some near the MAX cold pressure which means the hot pressures are over 60 psi+. Begin at the stock oe pressures as noted, drive around in a spirited manner and check pressures again. I've seen as much as 12-15# hot pressure increase on the track. There is a happy medium where you don't want squirm from a too low pressure HOT or it being rock solid from too high a pressure. There are different scenarios too: daily driving, HPDE's, AutoX, each with its' own set of data points.

I am running 40!