http://www.suvarnabhumiairport.com/e...umi-don-muaeng

Travel time is scheduled at 50 minutes, but you should expect longer travel times (~ 1:30) during peak times and during inclement weather.

The subway (MRT - blue line) is getting to be very challenging to use during peak commute times (AM in-bound, PM out-bound), especially on the side-by-side stations. I've had to wait for ~ 30 minutes in some cases and the platform can be jammed to the point where nearly no movement is possible.

These timetables, for direct transport between the two airports, may be more up to date?