Originally posted by EHM-1703 Philip
... and make sure you maintain V2+10 thru the initial climb section. I usually dont let VNAV/LNAV take over until 1,000 feet as I find this also helps.
Bit slow noticing this, but...
On the B738 CDU there is one "setting" that along with the climb thrust mode has a profound effect on the extended climb rate. This is the T/R ALT (on Project Magenta, it's on the PERF INIT page or N1 LIMIT page): this is the thrust reduction altitude, and is the altitude AGL where take-off thrust N1 is automatically reduced to climb thrust N1. Usually T/O N1 is 90%+ while climb thrust will hover around 70-80%. Per default, PM leaves this BLANK! Boeing default is 1,500ft. Without this being set, the A/T leaves T/O thrust in place until transition.
As for climb mode, unless you need a 8%+ climb rate (and there are one or two SIDs that call for such), stick with CLB-2 which will be more than good enough (easily 7%) for most SIDs. If you want absolute control, use MCP speed and climb, and set the VS to no more +4000.
Finally, just as Phil points out, getting your T/O and landing weights right can be a big help. I personally use a B738 fuel planning program that I found on the web somewhere that seems to do a reasonable job. I'll get it's "About" info once I get home tonight and post a link.
Without everything being set somewhat correctly, an unladen B738 will happily climb from ground level to FL350+ at 280kts/6,500ftm without breaking into a sweat...
EDIT: OK, it's designed for the PMDG 737 series (600-900), but like I say, I use it happily enough with the Project Magenta/POsky pairing (I just have to turn up some of the landing values to get sensible reserves at landing). Anyway, here's the link
http://www.metacraft.com/737NGFP/