i have done my research on here today concerning the z1 tubes and several have stated they felt better throttle response and more power.
in this link,the guy only had the drop ins and made a difference once coupled with a CBE.
DYNO - NISMO CBE and K&N Dropins
i wouldnt put too much faith in your mechanic friends.i have had the drop ins for 2 weeks now and i like em.i will be ordering the tubes here pretty soon as im satisfied from the reviews concerning throttle response.only trying to help here boss.GL
