Well, it's hard to recommend, but here it's what I'm gonna do:
Polish mod from DIY-magazine (1985). It's needed the older type of exhaust, not the 650E one. You can see there are 2 variants: sport and tourist(the B-B one with the smashed pipe). The second one will be better for the standard engine, at least less noise.
The exhaust gave 2,5hp more on dyno and 15% less fuel consumption on road tests at 80km/h. They made some adjustments as well.
http://denior.prv.pl/Here you can take a look at comparison of polish aftermarket sport exhausts (rusty punks with suspicious sport value but "nice" bass sound) and the DIY one that worked good, no matter if it looks like piece of ..., ok, ... not a master one??? The guys say that it works pretty good in high rpm, but it's too loud, and at idle ... bad sound ... no bass haha, who cares!?
I'll make one more silencer, don't wanna chat with cops every time
I'll turn the outlet pipe forwards and then again to the back with U-pipe to a full flow perforated pipe stainless silencer about 50sm (on the same line with the rear bumper), 1/3 empty chamber, 2/3 with glasswool. It can be placed beneath the bumper as well (if there is no an Abarth oil sump with nicely painted in red letters)
The Abarth Monza looks nice and must work cool. You can try it
About the carb, try to find Panda 30 Weber 30 DIC with
manifold like
Rusty's Uncle's one Greetings!
