I wouldn't ask a dumb question on purpose. So if I am, feel free to patronize me all you want.
I am trying to establish the maximum wireless throughput of an AP. (Wrt54G/DD-WRTv24micro)
I have the AP between a RouterOS box and a node. I used the MT Bandwidth Monitor - Tx:15Mbps Rx:7Mbps
Is it possible to achieve anywhere close to 54 Mbps?

Practical maximum 802.11 g/a throughput (in ideal conditions) is around 25Mbps. So stop dreaming about 54mbps, it's air rate. You can't get anywhere closer.