performance exhaust

[cspaur13]

i got a raw 80cc 2 stroke and i found a site with some mufflers like the a short 1 and and the extended chopper 1 on bicycle-engines.com but do they increase power and make it sound better and if u know any other sites that sell aftermarket exhaust for them and pocket bike mufflers that fit without being modifyied.
thanks,
cody