# What affects throwing distance?



## darcy32171 (Nov 28, 2013)

Just curious. My 2003 Murray 10hp 27, I did the Impeller mod. I find it does not matter what speed I go or what type of snow it is, it just does not seem to really throw it like some others. I even put new belts on it and the belt "squelches" when I kick in the auger.
I seen the neighbor blowing his city sidewalk. It had maybe 3 inches on it and he was just leisurely walking behind it and it was throwing the snow a good 20+ ft with ease. 
Does it come down to brand? What about how the blower chute is configured? My chute is a small rectangular hole about 4-5inches long and then the round chute ontop of that. You would think that would slow the travel of snow. If this blower is normally like this, I`m buying new next year. I even watched youtube videos of really old blowers, some 8hp newer ones and even 5hp ones and they seem to really throw the snow. Just baffled is all...Darcy


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## micah68kj (Oct 8, 2011)

Lots of of variables. Impeller diameter. Small impeller = less distance. Impeller rpm. (You can fool with pulley sizes to get more rpm. Engine power, depth of snow, two stage blowers work best when filled. Machine ground speed, type of snow. 
Lots of variables


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## td5771 (Feb 21, 2011)

also check your engine rpm. either with a cheap tester or by ear comparing it to a similar engine (careful not to rev too high)


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## GustoGuy (Nov 19, 2012)

Adding an impeller kit will tighten up the clearance of the impeller to the drum and will improve throwing distance especially for wet heavy snow. Rust will cause snow to stick to it and a smooth clean rust free chute and impeller and drum will throw snow better than a rusty one. Like others said you could install a slightly larger top pulley for your auger. Do not go too big because running your auger at much higher rpms could cause failure of your gear case. Going from a 2 1/2 inch top pulley to a 3 inch top pulley will usually increase rpm by 150rpms to 200rpms at most. Here is a rpm calculator that can help you figure out the differences in speed increases by going with a larger top pulley.
Pulley, Diameter Size Calculator


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## Piedmont (Nov 13, 2013)

Remember there's a lot of pieces to the puzzle that working together affects throwing distance and it's kind of a balancing act as well. Make a blower that can throw thick stuff fantastic and it will stink at throwing light. Make one throwing light stuff great, and it will stink at throwing thick. Things that affect throw are...

1.) The RPM of the impeller. Those old blowers the RPM was about 1000, the newer blowers are 1300 - 1400. That alone equates to a 30-40% increase in throw but there's other factors. 

2.) Exit strategy, which is applying physics to the opening of the chute to increase throw distance. Honda "funnels" the snow to a small area before exiting which builds pressure and it shoots out like a rocket. Everyone else that I've seen has big openings, no physics applied. .

3.) The size of the impeller... they are typically anywhere from 10" to 14". A machine with a 14" impeller spinning at the same speed as one with a 10" impeller should throw about 30% further.

4.) Clearance(s) between the impeller and outer housing. The tighter, the better. Honda employs tighter tolerances than most (which combines very well with #2 point above) and Toro approaches it completely different today by throwing the excess back into the auger.

5.) # blades on the impeller. More blades is better for thick snow but worse for light. Less blades is great for light but worse for heavy.

There are caveats. The further the throw, the more the blower bogs down. Those old blowers with impellers spinning at 1000 RPM, you could put them in 3rd gear and sure they may only throw the snow 5 feet but they have incredible throughput. Do that with a new blower with far throw and it'll choke and die it needs more torque/hp or slow transmission. Likewise, an 8hp machine, 28" wide, with a 10" impeller can typically move faster (because it's not throwing as far) than the same with a 14" impeller but the 14" impeller will throw further (or needs more HP to compensate for the additional torque needed for 14"). It's up to you which is more important.

Everyone seems to compare throw to a Honda, that is Honda seems to be "the baseline" everyone else compares to. Honda compensates for the huge throw in several ways. They use efficient components (bearings instead of bushings, as little drag as possible everywhere so more HP goes to throwing). Tight tolerances in the impeller. More HP (typically a 28" model has 8HP Honda is 9HP and OHV) and lastly Honda has a hydrostatic transmission (works on fluid) that is completely variable (there's no 1st, 2nd, 3rd, nor R1, R2) that lets you adjust the speed to let it crawl at incredibly slow speeds or fast... as much as it needs to compensate for the far throw. 

Each approaches it differently. Today they all have high speed impellers. But Ariens employs bigger impellers than typical, Toro employs a new technology that prevents throw being reduced by throwing the excess back into the auger, Cub Cadet (MTD I think) typically employ more HP and lastly Honda employes more efficiency, chute physics, tight tolerances, more HP, and a variable speed hydrostatic transmission. But there's a reason Honda's are so expensive. 

You could look at it another way, if all things are equal and your throw is okay for you you're likely having to spend less time out there than your neighbor .


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## darcy32171 (Nov 28, 2013)

GustoGuy said:


> Adding an impeller kit will tighten up the clearance of the impeller to the drum and will improve throwing distance especially for wet heavy snow. Rust will cause snow to stick to it and a smooth clean rust free chute and impeller and drum will throw snow better than a rusty one. Like others said you could install a slightly larger top pulley for your auger. Do not go too big because running your auger at much higher rpms could cause failure of your gear case. Going from a 2 1/2 inch top pulley to a 3 inch top pulley will usually increase rpm by 150rpms to 200rpms at most. Here is a rpm calculator that can help you figure out the differences in speed increases by going with a larger top pulley.
> Pulley, Diameter Size Calculator


Without the tool to tell me the RPM, that link won`t help me. 
My engine is a Tecumseh 10hp. The engine pulley is 3" O.D and the lower blower pulley in the manual says 8.40 O.D (I eye balled it with a tape measure and it looked like 8 1/4".


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## GustoGuy (Nov 19, 2012)

darcy32171 said:


> Without the tool to tell me the RPM, that link won`t help me.
> My engine is a Tecumseh 10hp. The engine pulley is 3" O.D and the lower blower pulley in the manual says 8.40 O.D (I eye balled it with a tape measure and it looked like 8 1/4".


answer 1350 
3600rpm from engine 3 inch pulley top 8 inch pulley bottom

The link worked for me


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## darcy32171 (Nov 28, 2013)

GustoGuy said:


> answer 1350
> 3600rpm from engine 3 inch pulley top 8 inch pulley bottom
> 
> The link worked for me


I did not input a RPM cause I did not know what it revs at. 
So could a guy try a 3.5" top pulley? Will it make a huge difference?
Piedmont, I wondered about Choking down the throw. Mine had a small rectangular port the snow exits through it first than into the round 6 inch chute. I just measured my Impeller and it is 12" across. As for the Impeller mod: I used rubber and there is zero clearance.


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## GustoGuy (Nov 19, 2012)

darcy32171 said:


> I did not input a RPM cause I did not know what it revs at.
> So could a guy try a 3.5" top pulley? Will it make a huge difference?
> Piedmont, I wondered about Choking down the throw. Mine had a small rectangular port the snow exits through it first than into the round 6 inch chute. I just measured my Impeller and it is 12" across. As for the Impeller mod: I used rubber and there is zero clearance.


Most engines operate at a max rpm of 3600. that would be the top number or rpm number

Clicking on the link should work unless it doesn't go there when you do it for some reason. with a 3.5 inch it calculated to 1575


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## dbert (Aug 25, 2013)

If you really want to know what the RPM of your engine or your impeller is, you could place a small piece of reflective tape to the pully or impeller and point this at it.
$10.79 plus $4.99 shipping. 4.5 stars with 123 reviews.
CyberTech Digital Photo Tachometer Non Contact Tach bundle CyberTech Cable Tie: Amazon.com: Industrial & Scientific


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## GustoGuy (Nov 19, 2012)

dbert said:


> If you really want to know what the RPM of your engine or your impeller is, you could place a small piece of reflective tape to the pully or impeller and point this at it.
> $10.79 plus $4.99 shipping. 4.5 stars with 123 reviews.
> CyberTech Digital Photo Tachometer Non Contact Tach bundle CyberTech Cable Tie: Amazon.com: Industrial & Scientific


Cheaper than a tiny tach they are $49.99 and only give engine rpm and it will show you the rpm of everything that spins. I bet you could put the reflective tape on the pulley and run the engine and see what the rpms are too.


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