Highest Speeds on Sidewinder/Thundercat

[Motorhead]

Motorhead, you bring up a valid point, and upon further thought, perhaps my ignorance has shunned some from posting. Thank you for bringing this to my attention. The purpose of this post is to share information and communicate ideas in making our snowmobiling experiences better as a community.

I edited my initial post, as I want to invite people to contribute, not scare them away.

I enjoyed seeing those crazy GPS speeds attained by your set up! I can only imagine how many combos you have spent time,and money on, to get those!

Conditions matter sooo much huh?

 

[Slow998]

144 mph speedo on my 21 Tcat. Probably just over .5 mile, just hoping to tick a few more numbers to feel like I could achieve Fleecer-type numbers.

-TD jukebox with header tunes
-Mismatched clutch parts that put the RPM close
-Stock SRX 1" Ripsaw track (biggest secret)

 

[74Nitro]

Stock gearing can get you at least 126mph GPS, I've done it on my dentists tuned srx

 

[Fleecer]

I enjoyed seeing those crazy GPS speeds attained by your set up! I can only imagine how many combos you have spent time,and money on, to get those!

Conditions matter sooo much huh?

Yes, absolutely....it has to be hard enough that a footprint can barely be negligible in the snow, yet can't be so hard that lubrication is nonexistent and it must be smooth for full shift out. Speeds can swing 15-20 mph depending on conditions.

 

[Fleecer]

144 mph speedo on my 21 Tcat. Probably just over .5 mile, just hoping to tick a few more numbers to feel like I could achieve Fleecer-type numbers.

-TD jukebox with header tunes
-Mismatched clutch parts that put the RPM close
-Stock SRX 1" Ripsaw track (biggest secret)

Whooooeeeee....another County Boy bending the needle!!

 

[Motorhead]

144 mph speedo on my 21 Tcat. Probably just over .5 mile, just hoping to tick a few more numbers to feel like I could achieve Fleecer-type numbers.

-TD jukebox with header tunes
-Mismatched clutch parts that put the RPM close
-Stock SRX 1" Ripsaw track (biggest secret)

We have also heard that many have seen greater out of box WOT speeds with the combination of lower stance and shorter lug of the SRX, when compared to the high in the seat Sidewinders. I’ve noticed wind will affect my top speeds more then the lower older models sleds that I have owned and raced against. I’ve placed all my suspension setting on lightest settings to grab a bit of extra, during my first years with this sled.

I now leave all settings for ride and handling, whereas where I ride (medium sized trails with lot’s of rollers and smaller straights) it’s what counts most until that One long straight away finally appears! 120 is easily attainable many times per ride with my mild tune and great traction days!

 

[sideshowBob]

I have never done an all out top speed run to see where my Sidewinder hits a wall but I have seen 122mph max speed on my GPS top speed recall and have seen 128mph on my speedo. With the gearing I run that is into a 5% overdrive so that is probably about it for max speeds on my sled. The scary part about those speeds is I am running the stock 141" x 1 3/4" one ply Back Country track and that is the main reason I have not pushed my luck running high speed runs.

 

[1nc 2000]

I have not run my sled out in top end.
132mph on plowed rd is the most i have seen on speedometer. When I looked down and saw the speed I let off the throttle. It was still pulling.
22-41 gears.
1.5 lug track with 196 studs makes me kind of leary to hold it wfo till it tops out.

 

[SideHogger]

 

[SideHogger]

125 was D&D TUNE 3 yrs ago with 21/41 gearing and actually hit 127 but forgot to take picture but no proof is no proof! Lol… Run, a little less than 2000ft. 132 mph run, with Hurricane 270 closed loop 22/41 gearing in about 1500 ft run last year. Both on ice and like Fleecer, my mismash of clutching with A LOT OF TESTING. 192 Ins studs, with Star Backers, Stock 1.25 ripsaw. Sorry pics so large…..

 

[Fords4life]

Not running numbers like some BIG DOGS on here but respectable for my general elevation of 5500 to 7000 feet, local thunder on the ice january 2020, 1320 foot ice radar run, 2018 stk thunder cat with my clutching run a best of 116.1 mph, same day my 2018 zr9000 sno pro 129 ran a best of 119.8 mph with pefi tune and my clutching, fast forward to january 2022 same lake radar run @ 6300 foot elevation as before but only 1000 feet long 2017 rtx se 112.4 mph, all these sleds had between 129 to 192 trail studs. Dream meter on my 9000 riot pulls 124 at will...no more though 24/50 gearing.

 

[Brent68]

My 2018 RTX isn’t crazy fast but is decently quick. Best 660’ off hard pack snow is 114.8 on GPS. Set up is a pro-mod engine build with a big turbo and TAPP clutching. It’s only geared for 120 at 1:1. This run was max performance pump gas set at 140Kpa, 20.4 psi. I use it as an everyday trail sled with full suspension/full weight. As an added bonus it gets better fuel mileage than my other 998s (one tuned, one stock) As a comparison, my 1200 turbo doo (pump gas) ran 116 in 660’.

 

[MBOKMAN]

I have a 2018 Thundercat with TD Jukebox header tunes (265/285/305/315). With stock gearing it hits 124 on the speedo no matter which tune in nearly all trail conditions. Selecting a higher tune just gets you to 124 quicker. The sled has a mild 144 1.325 studs in the stock 1.25 RIP2 track and stock 50/24 gearing. I love the quick accel of this gearing. Any faster and I would have big concerns of the track coming apart.

 

[74Nitro]

I have a 2018 Thundercat with TD Jukebox header tunes (265/285/305/315). With stock gearing it hits 124 on the speedo no matter which tune in nearly all trail conditions. Selecting a higher tune just gets you to 124 quicker. The sled has a mild 144 1.325 studs in the stock 1.25 RIP2 track and stock 50/24 gearing. I love the quick accel of this gearing. Any faster and I would have big concerns of the track coming apart.

I think the tracks can handle it fine. I would only be concerned on a track with high miles, especially if its spent most of its life at higher average speeds. Once a track gets to 6-7000 miles on a high-power sled, you are on borrowed time.

 

[Fleecer]

125 was D&D TUNE 3 yrs ago with 21/41 gearing and actually hit 127 but forgot to take picture but no proof is no proof! Lol… Run, a little less than 2000ft. 132 mph run, with Hurricane 270 closed loop 22/41 gearing in about 1500 ft run last year. Both on ice and like Fleecer, my mismash of clutching with A LOT OF TESTING. 192 Ins studs, with Star Backers, Stock 1.25 ripsaw. Sorry pics so large…..

Sidehogger, 132 GPS is about 139 speedo? In 2000 feet, that's darn good.