High Response Time : Weblogic v8.1

Our application performs really bad in our production environment. Same code
running on a different server (TEST or QA) is better. QA is bad when compared to
TEST. Inside  HTML there are references to images, css, js and the fetch times
as reported in firebug (firefox) for each one of them is around 1300 ms in PROD.
QA is around 700 ms and TEST less than 400 ms. PROD server is in not in the same
building as TEST And QA. But there are other applications on the same box and
their response time is less than 400 ms. So it is not the machine but it is a
problem with application or webserver set up. We also timed using
"wget" of linux to bypass browser and still notice the same high
response times. There is no encryption or any form of SSL here. Ping with 4K
size is in the range of 30 ms in PROD compared to 10-20 in QA.

What can we check to make sure there are no obvious set up errors in our ca