@Tim-HH and @richboy2307 -
I think it would help a lot to know which engine is being modeled.
If Greg Collyer's aircraft is the basis for the performance numbers (as it should be - it's the one that iniBuilds researched) - then the engine in the sim aircraft isn't an Allison J-33, it's a Rolls Royce Nene Mk. 10. Like many (most?) of the T-33s currently flying, Ace Maker is a Canadair license-built T-133 with a Rolls Royce engine.
John Terrell (aka Bomber12th, aka JohnnyT5000) pointed out in the MSFS forums that the start-up procedures and the performance seem correct for an RR Nene.
At 2:55 in this video, Ken Pacholski, at the time the owner of N133KK, describes the RR Nene in his aircraft as "more powerful, much more powerful" than the original Allison.
If all that is in fact the case, it'd be good if iniBuilds could specify the engine in the documentation.
@Dudley Henriques - I've been using that procedure in the T-33 (and in other early jets like the F-86 and the Fouga Magister) and it works well. I think I must have learned if from you along the way. Thanks!