Gearing Chart

[cannondale27]

On my 14 XTX stock gearing with 252 ish hp and overdrive 112 was the best ever on an ice track at 9150 rpms. On the 15 at low boost about 230 ish hp and stock 3.0 drivers, overdrive and 26/44 gears I have seen 118 on the trail. it is clutched for high boost so I was only turning 8450 rpms. the chart says 134 mph for that and I do not believe if I got to run full high boost and was on ice that I would do better than 124 ish so I have little faith in the estimated speeds on the chart.

If you lowered the sled and put a 14" wide 3/4 track with studs I bet 130+ would b doable. All the charts mean is with optimal clutching when you hit the revs that's what you will be doing. If you don't hit the speed just means you need more power or something like aerodynamics, drivetrain is holding you back. Try sucking the limiters up 4 or 5 holes once and see what happens.

 

[Yamadog]

If you lowered the sled and put a 14" wide 3/4 track with studs I bet 130+ would b doable. All the charts mean is with optimal clutching when you hit the revs that's what you will be doing. If you don't hit the speed just means you need more power or something like aerodynamics, drivetrain is holding you back. Try sucking the limiters up 4 or 5 holes once and see what happens.

I just wanted to make guys aware that just cause the chart says it does not mean that in trail trim you will get even close to that. Look at NASCAR at the things they used to do in qualifying vs race trim there was 15 mph more in the car but they could not drive them that way in a race.

That is what is supposed to be going on with the 14 XTX. 14" x 144"x 1-1/4" 2.86 drivers entire sled lowered 28/42 gears and about 350 hp.............. if it ever gets done!

 

[TPAY243]

Yamadog i know what you'r saying i don't think i will be able to run 127 mph in trail trim i have seen 110 mph several times on packed trail across the lake. I am pretty happy with that i guess my question is can i achieve that same top end speed and get there quicker with a different gear ratio, i whant to be able to run with the 800 2 smokers in a 1000 ft drag. I should have them covered on top end but my buddy's got a 800 polaris i have yet to run him, but it is pretty quick just whant to make sure i got every thing right before i issue the challenge

 

[Yamadog]

Ok what you have to remember is your going through several diff systems in the primary, secondary, gear box , jackshaft, driveshaft then to the final equation of the driver size and pitch. You can play with gears and find one that may get you off the line quicker but I would have to think you are going to give up top end unless you extend that by achieving over drive. The guys I know that have installed 21/41's in N/A sleds gave up a bit leaving the line to get more at the top end.

I cannot remember if you are N/A or turbo but if you are N/A and seeing 110 and capable of running with 800's I would say Yamahoo cause you are basically in a 600 class sled. About 90% of the guys on here would have sled envy if they could do that. I ca tell you over the last 5 yrs I have had 4 Polaris pro R's and 1 Pro S 800 and none of them could do that. the speedos all said 104 at max and my GPS said your a liar !!! 98 was it! I run with a group of guys that are all on late model Doo's and they dould not catch the Pro s so what does that tell ya?

by changing helix angle and spring wind you can control the shift our of the secondary in relation to the primary to slow it down or speed it up but in my opinion leaving all other things the same and going taller on gears will not gain on the bottom and the top.... if that makes sense?

Guys like cannondale and Nospro on here spend days testing different packages to gain 10ths of a second with gearing, ramps, weights and alligator suits

 

[TPAY243]

Yamadog I am far from stock running Hurrican 190 trail kit (6 pounds of boost),Hurrican clutching, 24/41 gearing.(The clutches are not machined for overdrive) I totally agree test ,test,and then test some more i have another set of gears to try it is just a pain changing them with that oil tank on the chain case cover, I will have to get some sort of base line and then go from there. I really do appreciate all the input

 

[cannondale27]

Yamadog I am far from stock running Hurrican 190 trail kit (6 pounds of boost),Hurrican clutching, 24/41 gearing.(The clutches are not machined for overdrive) I totally agree test ,test,and then test some more i have another set of gears to try it is just a pain changing them with that oil tank on the chain case cover, I will have to get some sort of base line and then go from there. I really do appreciate all the input

Just Mark your clutches. I assume you are not hitting rev limiter? If you are 1/8 from edge of primary you would benefit from gearing higher yet since clutch is almost fully shifted and that is not as efficient.

 

[SnoNinja]

On my 14 XTX stock gearing with 252 ish hp and overdrive 112 was the best ever on an ice track at 9150 rpms. On the 15 at low boost about 230 ish hp and stock 3.0 drivers, overdrive and 26/44 gears I have seen 118 on the trail. it is clutched for high boost so I was only turning 8450 rpms. the chart says 134 mph for that and I do not believe if I got to run full high boost and was on ice that I would do better than 124 ish so I have little faith in the estimated speeds on the chart.

Using the gearing calculator app, your combo on the 15 is 113 mph without overdrive at 8450. OD would get you that extra 5 mph. based on your setup pulling 8450 and overdrive, it looks like you are right on the numbers.

 

[cannondale27]

Using the gearing calculator app, your combo on the 15 is 113 mph without overdrive at 8450. OD would get you that extra 5 mph. based on your setup pulling 8450 and overdrive, it looks like you are right on the numbers.

View attachment 118269

What the actual link for that app? Cool

 

[SnoNinja]

What the actual link for that app? Cool

Go to the Apple App Store and search Snowmobile Speed Calculator.