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Metalhead
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A new ramp for low elevation - primarily in Europe/Scandinavia from what I know so far.

966 @ 51 grams.

I'll put them up to the other ramps after to compare.

Similar to the 951, but the mass is distributed a little differently. I think it will have more bottom end and lower engagement speed. I'll test this out over the winter and have other test guys run it too. Im going to make a guess that it will be less resistant to rpms sucking down at higher track speeds. Like say when you are doing a wheelie on a trail (to get from this snow stash to that snow stash) and wheelie over a hill at 40~45mph, the ramp will be more resistant to not having the engine drift rpms lower when the skis land on the ground; less rpm drift at mid to higher track speeds can be reduced by less mass on the end of the ramp.

The BRP techs who design these ramps are the smarty of the smart smarts! I hope to meet some one day to learn more how they go about developing tuning objectives.

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Metalhead
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Discussion Starter · #3 ·
Yeah very interesting. Last season I was able to get 2700~2800 engagement with 990 and 951's. I'll check this 966 ramp for engagement speed right away.

I got a spring tested last season 155/370 so was able to get the engagement speed down even more with the kit and have it at 3000 rpms with certain ramps (as an option); so i'll try that out and complete a chart i'll put in my 850 Blog.
 

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Metalhead
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Flyweight grams (mass) used, is a representation of engine torque being converted to the track.

Horsepower - torque increase

You can go "with good common sense" as if deciding of more-engine-torque converted to the track is done with more flyweight. This is so IF the horsepower increase is done at the original engine speed.

You had 160hp at 7950 rpms. Now you have 210hp at 7950 rpms. Since the rated power speed did not change but the torque did, increasing, then the mass of the lever must increase to preserve correct engine speed.

I like the idea of the 966 ramp itself having more mass to satisfy the need for more mass when going from 160hp to 200+hp; I already have 966's gone out to my turbo test guys with a new Popeye arm...WOO!

Trouble converting existing power
Since the 2017 G4 summit release, there were sleds arriving at low elevation with ramps, not heavy enough; complaints about overrevving, not enough pivot weight and/or no pivot weight available to tune. Changing a primary spring might not have been enough of a force change to lower engine speed, including lowering the clicker.

Aaen law; if need less engine speed, then add more flyweight (mass).

Aaen rule of thumb; 1 gram = estimated 200 rpms engine speed change.

If you have 8100 with say 60grams, then to get 7900 add one gram; making 61 grams.

…ok lets see what these ramps look like.

966 ramp part number 417224147

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A new ramp for low elevation - primarily in Europe/Scandinavia from what I know so far.

966 @ 51 grams.

I'll put them up to the other ramps after to compare.

Similar to the 951, but the mass is distributed a little differently. I think it will have more bottom end and lower engagement speed. I'll test this out over the winter and have other test guys run it too. Im going to make a guess that it will be less resistant to rpms sucking down at higher track speeds. Like say when you are doing a wheelie on a trail (to get from this snow stash to that snow stash) and wheelie over a hill at 40~45mph, the ramp will be more resistant to not having the engine drift rpms lower when the skis land on the ground; less rpm drift at mid to higher track speeds can be reduced by less mass on the end of the ramp.

The BRP techs who design these ramps are the smarty of the smart smarts! I hope to meet some one day to learn more how they go about developing tuning objectives.

attachicon.gif
966 ramp.jpg
2 grams heavier than the 968, how does the profile compare to 968? Could be a nice ramp for a 129/137 with a 150/350 0r 150/370
 

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Is there any possibility to see, without removing a ramp, to see if my sled has the new 966 ramp installed?

My sled is a brand new -19 Lynx 850 and I'm in Sweden, thought that since the new ramp was intended for us than perhaps my sled came with it even though it shows the 990 ramp in the spare parts manual.
 

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Metalhead
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9,232 Posts
I ran the 966 ramp in Revelstoke (griffin and keystone) and they were mint. Sunday 2nd to Friday 4th.

  • 155/370 primary spring
  • 966 ramps
  • Pivot bolt kit
  • 225/330 secondary spring
  • D5 (850) helix

966 (15.9g pivot) for 6000 feet at first and did not know we were at 7000'+ so i was at 7800 rpms. I clicker'd up to 4 and 7950~8000 rpms, sometimes 8050.

I pulled out to 14.8g and back to clicker 3 for 6500~7500 feet and power by the hour at 8000 rpms.

3200 rpms engagement speed with pivot weight for 6500 feet. Went as high as 7200 at keystone.

Engine braking coming down the big open hills was fairly decent, holding to about 24kmh (14mph) and then I tightened up the belt a little more and down in the trees (tree riding) when i was able to come down on a tracked trail, nice and steep, engine braking would hold until 12kmh (8mph).

I come down steep enough that I had to do wrong foot forward, put sled on its side and having a hard time concentrating on the brake, I flick the throttle and "whammo", engine braking engages and takes me nice and gently down the hill. 4 foot base, 2 feet fresh...steep as fk. ! ! ! haha

Almost a graveyard but not quite. Got a 9.5, 9.7, 9.6 from the judges. :happydance

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Metalhead
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No Bud, they are absolutely available. I have customers in QC who've had case files open about belt failures and/or rpm issues and the dealers have replaced the 990's with 966 under warranty - here in Canada.
I had to make setting sheets for them to run the clutch kit with the 966 ramps. And I have 4 sets here in my office.(not for sale, sorry) :D
 
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