I live in an area which gets an average of 14ft of annual snowfall........needless to say that after a couple months the snowbanks get to be about 5 ft high and the blower has to blow it back and up quite high. My 5 year old 2 stage blower was starting to loose a bit of distance so I tuned it up and replaced the belts which made a slight improvement . I was considering replacing it when I found a site online which sold a kit which claimed to improve the throwing distance of any blower by reducing the impellor clearance. I looked at some online videos and testimonials and though I was still sceptical I figured it would be worth a try. I made my own flaps out of a heavy rubber truck mudflap and some 1/4 dia by 3/4 in bolts , nyloc nuts and washers
.It took about 2 hrs of work but the results are amazing........the blower throws snow farther than when it was brand new by about 25%,
you can buy a kit from http://smllengns.tripod.com/ but it is very simple to make your own as I did !