What can are you running on the 872?

[fredw]

xp-x 174x 3 885cc
525lbs(full of fuel and oil)
Racers edge skid
20.5grams, blue-yellow-spring 413 ramps
dynoport pipe and y pipe, mbrp can
boyseen reeds
shockwave helix
42mm carbs


My old signature, but this is on a ptec not etec

 

[mtncat]

Primary
160-320 spring
415/441 ramp
Running thunder shift arms with a total weight
Of arm and pin = 52.5 grams, without rollers, shims or cotter pin
Clicker 3
21-51 gearing, 25% 110/91 fuel
V force reeds
Stock was
160-350 spring
46.5 grams with stock arm and pin
415/441 ramp
Clicker 4
20-51 gearing
Secondary
Shock wave progressive with 165-315 spring
Stock, 44-40 with purple-purple
The 872/880 battle will come down to the knowledge of the tunner and who
Can harness the torque that these engines produce
Side note- 900 cat twin has a 76 mm stroke 800 skidoo has 75.7
The grunt of these engines has to be harnessed to enjoy the full benefit
Of these big bores

 

[winter brew]

Using stock sewing machine silencer....but with mesh hood, the clutches and all the other noises under the hood are the loudest thing on the sled.

 

[fredw]

Let's talk track speeds with the 872... Add elevation

 

[mtncat]

Cant compare track speed from different ridding areas all over the country and have informative info, speeds will vary from day to day on the same mountain same sled.

 

[fredw]

That's actually a bunch of bull, your track speeds don't jump around, they stay with in a few mph on different conditions... Been running bb over two decades..Not my first day comparing them

Elevation will change them, or a motor with limited tq

 

[mtncat]

so I ride at 10,000 ft I have a foot of fresh on a good base and a 25 degree climb, your at 8000 ft 2 foot of fresh and no base and a 45 degree climb this would be a good comparison on the torque of my little!!! 872 vs your big!!! 880, what would my track speed vs actual ground speed be compared to yours? As far as your years of big bore experience at 2 + decades is good and respectable, how about 3 + decades beginning with the 500 Centurion punched out to a 605 or a 600 Indy punched out to a 707, years don't matter, retained knowledge and a open mind to all forms of products for our sport and industry is far more important. comparing track speed on a computer to see if your big bore has more torque than mine is the same as looking for Bigfoot, a waste time!!

 

[pfi572]

I say the same thing as to comparing track speeds.
Waste of time and only for your own tuning.
To many variables , period.
Entertainment on the forums is all !!!!

 

[fredw]

Well here a easy way to figure hp gains by track speeds

Your average speed climbing is 45mph stock and you then after your doing 50 mph you have gained 10 percent