a great read steve thanks for sharing the japs also tend to have biiger exhausthousing and laggier cars cause they spend alot of time in heavy traffic and off boost. if you want that low down power I would be tempted to go for the the smaller exhaust housing and put up with the lack of top end if it exists. I also think the compression drop was part fo the cause for the lagg to be exadurated (spelling) as the cars stock compressin is very high and I think it was required for safety. put hte smaller exhaust housing in and see what happens you might get a surprise and it might be quite good b4 you go and change exhust manifolds.
meggala