i think where the lbf measurements came from were different sources from the pratt whitney f article i can already see that the stats come to kn for the engine while the high performance engine the general electric rolls royce f is also kn for the entire system there is a minor change in lbf but i am not sure these are accurate i dont know why the secondary engine is labelled high performance anyway if i can't find credible sources then i will remove this yes i know i'm not signed in but i am the exile