Having finally gotten a really close look at the A5, some noteable differences pop up right away between it and the A3
The piston is smaller, but the stroke is longer, again, it would be a hideously BAD idea to try mounting that speed kit on an A3 due to this.
The main jet is a # 51, not the # 48 that came with most A3's.
The piston does not have the tiny dip in the center that the A3 has.
The carb attachment to the cylinder is very, very different.
The new transmission sucks. (my opinion, is all)
IMOP, having a really intense knowledge of both engines, I would have to say that the A3 is probably superior, it was simpler, and from experience with both, slightly more powerful, if prone to overheating in the summer.
(which the A5 is not, like one has to worry about that in frikkin michigan...)
Sometimes technology isn't all it's cracked up to be, cause the A3 put out more 'juice' than this A5 does, so I got to thinkin, if one took the pistonarm assembly out of an A5 and put it in an A3, and THEN put the kit on it...it would probably scream....
But you'd really hafta be nutz to do that....a show of hands ? how many are that insane ?