I finished the work on the velocity stack on my 4 cyl ,2.5 xj,5 spd. The stack worked out to 2.625 inches long,all I could get and still run the air cleaner. As I said I don't have a dyno, there was a noticeable change in performance,(not the kind I had hoped for). The power started leveling off around 4400 to the point of no need to to turn it any higher. Drove it two days , no change. I removed the stack, when back to the stock 2.5 set up, did not remove the battery cables , ran as before would pull steadily and smoothly past 5200. I said I would let you know,I do not consider it wasted time . Thanks