Arctic Chat

Nick · 09-21-2005, 08:50 AM

INTERACTIVE SNOWMOBILE GEARING CHART

Download this gearing chart in Microsoft Excel® format and just plug in your Upper and Lower Gear Ratio along with your circumference of your driver (in inches) and the RPMs you are running. Then it automatically calculates your speeds for you.

It's pretty slick!

This was sent to me by Mike (Firecatsrt)!

Send him the free beer!

Nick

firecatsrt · 09-21-2005, 10:32 AM

thanks for putting this up Nick, I thought it would be a good tool for everyone to use because the formula to figure it all out is pretty tricky and this does all the hard stuff for you.

and i must give the credit to a fellow racer Jim Muth for creating this chart during his busy work day

Cats4Life · 10-03-2005, 05:49 PM

This is a really cool tool! Just one quick question, what does the speed at 1:1 mean? I see the speed go higher at 105%, 107% etc. so was wondering what the 1:1 ratio stands for and how to get to 105% or higher. Thanks, Rich

firecatsrt · 10-03-2005, 08:17 PM

1:1 is when the belt is dead center on the clutches and the track is spinning at the same speed as the motor, the 105% + is when your clutches shift all the way out and you kinda go into "overdrive" so to speak, if you are running at 115% then you are basically maxed out, if you do it consistantly you may want to gear up as you are topping everything out and may risk blowing a belt.

Cats4Life · 10-03-2005, 09:33 PM

Excellent explanation, I understand it now.

Thanks, Rich.

Auggie · 10-04-2005, 11:14 AM

Well, a 1 to 1 clutch ratio means that the drive belt in the drive cl. is at the same dia. as the drive belt in the driven cl. When the cl's reach overdrive the drive belt is at the top of the drive cl. (8") and the drive belt is low in the driven cl. (7").
7 div. 8 = .875. or 112.5% The jackshaft does spin at the same rpm as the engine and in fact will spin faster then the engine when the clutches go into overdrive but because of the dropcase gears the track will never see engine rpm. Not even close.

Auggie

firecatsrt · 10-04-2005, 11:27 AM

good explanaition auggie...

spencer racing · 10-09-2005, 08:21 PM

How about something for the diamond drive gearing?

firecatsrt · 10-09-2005, 09:07 PM

do you have the formula to figure it out? if you have that i can make one up. if anyone has the formula i can make another excel sheet up for diamond drive.

Reeb · 12-09-2005, 10:13 AM

I've been trying to talk to some engineers about the DD gearing and a few guys can't even give me answers. They just claim that I'm messing with all the time and energy they put into these sleds and I'm screwing it all up.......

My problem is that I have a D&D 900 and a Cutler 1 Liter in M-sleds and they top out at 80ishmph. I want to see 90-95mph speeds, Only problem is nobody can tell me what a 60/60 ratio(X-Fire) tops out at, or a 57/63 etc etc.

Should I got with X-Fire gearing or F6 gearing?