exhaust leak, not building boost
 

Need some advice! I have had an exhaust leak for a little over a month now. It has been getting worse and worse and then it started to have bad turbo lag. And speraticley it wouldnt boost over 5 pounds... So I have now taken the turbos off and havent found any signs of leaks from the manifold to the turbo...Any one know of any comon leak sources. I have an autocross this weekend and have to get this beast back together. Also I was planing on useing RTV copper "high temp" (700 degree) gasket maker when I reaseamble everything, is this ok?
Thanks in advance:D