Kas Kastner, on modifying SU carburetors
for more power:
Over 20 yeas of trying to get more out of the stock S.U.'s I
found that the time spent in most cases was a total loss. Thinning
the butterflies does help a bit but anything else other than velocity
stacks has just been pure anguish. My tests were of the back to
back variety on a properly registered and calibrated engine dyno.
In other words, your time and effort is best spent elsewhere
if you are trying to gain additional power. SU's are very good
carburetors that are almost impossible to improve upon once you
get the carb size and needle jetting right.
Also see Dyno tuning SUs with stacks
Retturn to the page top