Dustin_Drews
02-28-2010, 08:23 AM
Hello gents,
I am thinking about building my own hybrid quad with a CVT transmission to use for harescrambles and endurance races.
Basically from scratch... Have been reading on this section an have yet to see any other guys do the type of build I am thinking about...
This is what I am going for... A copy of the 250r frame geomerty with a no link rear shock.
The engine is going to be a built 400 Fugi engine, The same engine that is found in a 400 polaris scrambler that produces about 65 hp.
The tranny will be a CVT belt set up same used on most 4x4 quads.
What I am shooting for overall in my build is a quad that has a dry weight of 325 pounds. That I never have to change the oil or worry about cleaning the power valve it, or ever have to think about shifting in the tight woods meaning always being in the perfect gear but still has a top speed of around 80 mph.
Now I know that CVT transmissions have there place in the world they have been used for years on snowmobiles and they have pretty much taken over the Jr dragster seen, the UTV seen and they are even used in radio controlled cars!
I am wondering why people have not used them on 2 wheel drive sport race quads? The set up I am thinking is using a Fugi engine from a polarirs 400 scrambler.
Now being a 2 stroke it would be simple and being a 400 it should make good power and be pretty light. I could get 60hp really easy from what I have read?
I know the downside of the two strokes is the HIT of the powerband... But with the CV tranny you never feel it on a snowmobile so that should not be an issue on a quad and also eliminates the need for a powervalve.
Another benefit of of the cvt tranny and a 2 stroke engine is you completely eliminate all oil changes!
Because you have no engine or tranny to lube.
The down side that I can think of right now is free wheeling and no compression braking. With that being said everyone is switching to the recluse and loving it so this should not be an issue!
Another thought is you could have a rear had brake in place of the clutch for feathering the rear brake!
Fatigue is the big killer in these races and with out shifting and clutching I think it would take alot of strain off of the driver so he could focus on driving!
Also I think you would get more traction to the ground with the set up instead of dropping the clutch on a hill and spinning out?
I have not studied the engine upclose but I also think I could mount the engine flush with the bottom of the frame along with the radiator and maybe even lower the fuel tank some to get the lowest center of gravity possible!
With all the benefits I listed what are the down sides that I am overlooking?
Thanks for your time and input! Please do not hate me for trying to ruin your sport quads by putting a cvt in them.
Thanks for your time!
God Bless,
Dustin Drews
I am thinking about building my own hybrid quad with a CVT transmission to use for harescrambles and endurance races.
Basically from scratch... Have been reading on this section an have yet to see any other guys do the type of build I am thinking about...
This is what I am going for... A copy of the 250r frame geomerty with a no link rear shock.
The engine is going to be a built 400 Fugi engine, The same engine that is found in a 400 polaris scrambler that produces about 65 hp.
The tranny will be a CVT belt set up same used on most 4x4 quads.
What I am shooting for overall in my build is a quad that has a dry weight of 325 pounds. That I never have to change the oil or worry about cleaning the power valve it, or ever have to think about shifting in the tight woods meaning always being in the perfect gear but still has a top speed of around 80 mph.
Now I know that CVT transmissions have there place in the world they have been used for years on snowmobiles and they have pretty much taken over the Jr dragster seen, the UTV seen and they are even used in radio controlled cars!
I am wondering why people have not used them on 2 wheel drive sport race quads? The set up I am thinking is using a Fugi engine from a polarirs 400 scrambler.
Now being a 2 stroke it would be simple and being a 400 it should make good power and be pretty light. I could get 60hp really easy from what I have read?
I know the downside of the two strokes is the HIT of the powerband... But with the CV tranny you never feel it on a snowmobile so that should not be an issue on a quad and also eliminates the need for a powervalve.
Another benefit of of the cvt tranny and a 2 stroke engine is you completely eliminate all oil changes!
Because you have no engine or tranny to lube.
The down side that I can think of right now is free wheeling and no compression braking. With that being said everyone is switching to the recluse and loving it so this should not be an issue!
Another thought is you could have a rear had brake in place of the clutch for feathering the rear brake!
Fatigue is the big killer in these races and with out shifting and clutching I think it would take alot of strain off of the driver so he could focus on driving!
Also I think you would get more traction to the ground with the set up instead of dropping the clutch on a hill and spinning out?
I have not studied the engine upclose but I also think I could mount the engine flush with the bottom of the frame along with the radiator and maybe even lower the fuel tank some to get the lowest center of gravity possible!
With all the benefits I listed what are the down sides that I am overlooking?
Thanks for your time and input! Please do not hate me for trying to ruin your sport quads by putting a cvt in them.
Thanks for your time!
God Bless,
Dustin Drews