1,000ft

[sideshowBob]

As stated the factory clutches will already overdrive. When a sled is using its overdrive to gain top speed mph its loosing efficiency rapidly with declining track hp as the belt speeds go up. You would only gain mph on a sled, by using overdrive, if it is already geared too low for top end speed when the clutches are in a 1:1 ratio.
Overdrive can be a compromise to a situation when using lower gears for quick acceleration but still maintain a descent top speed but its not a free ride.
Ski Doo has always had their clutches designed with a pretty big overdrive to allow lower gears to keep the sled feeling responsive but notice most Ski Doos don't have long legs.
In the Dragy I posted earlier my sled was geared for @ 102mph at 1:1 and ran up to 112mph using its overdrive but you can see it didn't gain much speed after 660' like higher gearing would have delivered.
JM.02c

 

[Turboflash]

FB is like the dreamometer, a good 5-10mph faster than reality

Yeah, at the bar every guy's sled goes 120+!!

 

[Turboflash]

As stated the factory clutches will already overdrive. When a sled is using its overdrive to gain top speed mph its loosing efficiency rapidly with declining track hp as the belt speeds go up. You would only gain mph on a sled, by using overdrive, if it is already geared too low for top end speed when the clutches are in a 1:1 ratio.
Overdrive can be a compromise to a situation when using lower gears for quick acceleration but still maintain a descent top speed but its not a free ride.
Ski Doo has always had their clutches designed with a pretty big overdrive to allow lower gears to keep the sled feeling responsive but notice most Ski Doos don't have long legs.
In the Dragy I posted earlier my sled was geared for @ 102mph at 1:1 and ran up to 112mph using its overdrive but you can see it didn't gain much speed after 660' like higher gearing would have delivered.
JM.02c

Agree. Cut clutches is a bandaid for gearing that's too low most of the time. However, it's a tact of diminishing returns meaning the right gearing and traction in 1000' is faster (MPH) than low gearing with OD. Arguably, lower gearing w bigger OD might be quicker (ET)? KnappAttack can straighten us out on that.

 

[sideshowBob]

Agree. Cut clutches is a bandaid for gearing that's too low most of the time. However, it's a tact of diminishing returns meaning the right gearing and traction in 1000' is faster (MPH) than low gearing with OD. Arguably, lower gearing w bigger OD might be quicker (ET)? KnappAttack can straighten us out on

Having some overdrive to fall back on at the big end is handy on a day when conditions were so good you needed some more mph ability at the end of the track without over revving.
LOL
Always good to have a little extra in your back pocket.

 

[Turboflash]

Most of the bar racing I get into (ie look for lol) is ET to 1000 or 1250'. First one to "line to gain" wins. Rarely is it MPH cuz there's no way to know what it is. So, if one is going mostly impromptu bar race, work on 1000' ET. At least in my neck of the woods. Lots of studs, high HP, fast upshift, and leave on yellow. If you get 'em from the dig by 2-3 lengths, they'll never be able to run you down in 1000' unless they have 400HP and you have 250.

 

[Doc Harley]

Most of the bar racing I get into (ie look for lol) is ET to 1000 or 1250'. First one to "line to gain" wins. Rarely is it MPH cuz there's no way to know what it is. So, if one is going mostly impromptu bar race, work on 1000' ET. At least in my neck of the woods. Lots of studs, high HP, fast upshift, and leave on yellow. If you get 'em from the dig by 2-3 lengths, they'll never be able to run you down in 1000' unless they have 400HP and you have 250.

Perfectly stated. I'm trying!!

 

[Turboflash]

BTW - the corrolary to this is even if you have lots more HP, and a theoretically faster sled on paper, if they get you 2-3 lengths from the dig, it will be tough to run them down to 1000'. At the 1000' stripe, you might be coming past them 30+ MPH faster than they're going, but at the line you lost. First 60-100' is really important.

 

[Doc Harley]

I've always, always put an Emphasis on the dig. that's everything. 300hp to fall back on helps, but not as much as you'd think when chasing a competitor down.
beside....its very difficult to measure1,000ft on a lake. It's more of an imaginary line, that I can easily extend 200'

Me: what?!?! I thought we agreed it was to be just past the tree extended off the shoreline! I was wondering why you quit!
Him: I didnt!!!

Lol......its just a game.

 

[Trailleader]

I agree with the 115-120 range.
Have to catch up this year
I’m digging out the 998 that’s been resting in the corner of the shop for the last 3 years. It has stage 4 pefi on it and some other ideas to throw at it.
Boost has more boost and stutter. I hope that’s running 105 plus in 500ft

 

[1nc 2000]

I've always, always put an Emphasis on the dig. that's everything. 300hp to fall back on helps, but not as much as you'd think when chasing a competitor down.
beside....its very difficult to measure1,000ft on a lake. It's more of an imaginary line, that I can easily extend 200'

Me: what?!?! I thought we agreed it was to be just past the tree extended off the shoreline! I was wondering why you quit!
Him: I didnt!!!

Lol......its just a game.

Let me know when you are going to Lake gogebic. I have to take a ride over on my sled.
I have yet to run it out on a lake. All snow effect snow on the lakes around here. Sunday thru Tuesday works for me.

 

[Doc Harley]

Let me know when you are going to Lake gogebic. I have to take a ride over on my sled.
I have yet to run it out on a lake. All snow effect snow on the lakes around here. Sunday thru Tuesday works for me.

No problem, Tim. I rent a place in land-o-lakes. You can pull an over nighter and/or i can ride back with you to Munising area, Putz around Grand Marais, Pine Stump, etc. Its been a while. Froggys, jack pines, etc.ilk lock in at the buck horn for a night.
Sounds good

 

[74Nitro]

Dragy shot with stock muffler. Post #20
111.99 1000ft
114.57 1/4

Dragy is sweet.

New modern incarnation of the old Gtech/Gtech pro. I actually used my old Gtech (accelerometer version not GPS) on my Sportsman ATV when doing PC-V tune testing and clutching work and it was quite consistent and repeatable on my 0-60 runs. I prefer to make a minimum 3 runs and if they are...

ty4stroke.com

 

[Doc Harley]

Dragy shot with stock muffler. Post #20
111.99 1000ft
114.57 1/4

Dragy is sweet.

New modern incarnation of the old Gtech/Gtech pro. I actually used my old Gtech (accelerometer version not GPS) on my Sportsman ATV when doing PC-V tune testing and clutching work and it was quite consistent and repeatable on my 0-60 runs. I prefer to make a minimum 3 runs and if they are...

ty4stroke.com

Thanks, 74nitro....I'm going to save that to notes. Just to run that mph against my MS16sm tune. Reference only....

 

[sideshowBob]

Unfortunately where I am in Canada we have virtually no local bar racing...I wish we did.
Pretty well all the head to head racing I have done for many decades is at the locally organized snow drags with Christmas tree start lights in communities around where I live. I never get to race anyone in the group I ride with as honestly I have no competition, no one wants to race me, and it would be a waste of time....heck no one will even race my old Yamacharged Attak when I bring it out.
I always have had to leave on the green or get red lighted so its been reaction time and sled setup...very fun! Our snow drags have pretty well always been 660' with the odd exception. As stated in a drag race mph is not relevant but ET is but this post was about 1000' mph and setting up for max mph in a given distance is a lot different then setting up for quickest ET. Amazingly the quickest sled in a given distance a lot of times is at a lower mph crossing the finish line as it takes time to build speed.
After a drag race you always hear from the guys you beat "I was catching you big time"

 

[Turboflash]

Unfortunately where I am in Canada we have virtually no local bar racing...I wish we did.
Pretty well all the head to head racing I have done for many decades is at the locally organized snow drags with Christmas tree start lights in communities around where I live. I never get to race anyone in the group I ride with as honestly I have no competition, no one wants to race me, and it would be a waste of time....heck no one will even race my old Yamacharged Attak when I bring it out.
I always have had to leave on the green or get red lighted so its been reaction time and sled setup...very fun! Our snow drags have pretty well always been 660' with the odd exception. As stated in a drag race mph is not relevant but ET is but this post was about 1000' mph and setting up for max mph in a given distance is a lot different then setting up for quickest ET. Amazingly the quickest sled in a given distance a lot of times is at a lower mph crossing the finish line as it takes time to build speed.
After a drag race you always hear from the guys you beat "I was catching you big time"

Him: "I was catching you big time.,"
You: "Maybe but you didn't."