Polaris 850 turbo. Who’s running what ?

[andrew90]

I have been running 800 Axys for years with great luck. Between my different sleds a couple BD st’s and a MTNTk I’ve got 15000 plus miles with almost no turbo related issues or break downs. I’ve been really happy with them performance and reliability.

I’ve seen so many mixed reviews/experiences on the 850’s I’m unsure what I want to do. I have one stock 850 and will he building a turbo for next year to replace one of both of my 800 ST’s I’ve had great luck with bd but I know the 850 has been different for them. I rode a silber 850 ran clean and good was slower on the bottom end then my 800’s and just don’t pull that hard like I enjoy. I typically run 8-10 psi in the 800’s I find that’s where they really start to work good.

So who’s running BD agility or water to air ? What else are guys liking ? Does food clutching make the Silber fast off the bottom end ?
What about forced turbos or MTNTK or anything else ?



Clean/fast throttle response for tree riding and I typically like water to air seems the most consistent.


Sent from my iPhone using Tapatalk

 

[Scott]

Last year, I was running the 2019 Boondocker Sidekick in my 2019 Polaris 850.
High boost, intercooled, tunnel dump exhaust, running on straight 100LL.
Original 2019 Polaris factory ecu tune.
Boondocker tune was 4.01, I think.
STOCK OEM vents on air intake.
STOCK Polaris head.
I ride from 5000-7500 most of the time. SOMETIMES unload at low as 4300 (at Seeley Lake).

Early on, I had some bogging issues in mid-range, but no DET.
It was rich.
I bought the Fire and Ice intake vents to add.
Rich condition was GONE. It ran so amazing after that.
No bog, still no DET.
Still running stock head.
Holy cow it was fun.
Turned 8700 rpm with my X3.2 track all day long.

I had my sled in the shop in January 2020 for something else, and they did the Polaris factory 2020 ecu reflash AND the BD tune that is supposed to go with it (I think it was 4.02).
It ran ok, but not like it did last spring.

I'm going to test a new updated tune that should be out for download soon.
I've also got the new BD intake vents installed and ready to ride.
I'll share my results here.

 

[snosfun]

I've got a '20 850 with a mtntk turbo kit and it's good. I like the ecu flash tool that comes with the kit, pretty slick. Another thing I really like is running straight pump fuel. My Silber kits in the past I was mixing av gas. Shawn says that it can run up to 12 psi on pump. Never tried it that high yet, I run around 7psi. Going to turn it up more and see what it can do.

 

[mt.sledder]

Last year, I was running the 2019 Boondocker Sidekick in my 2019 Polaris 850.
High boost, intercooled, tunnel dump exhaust, running on straight 100LL.
Original 2019 Polaris factory ecu tune.
Boondocker tune was 4.01, I think.
STOCK OEM vents on air intake.
STOCK Polaris head.
I ride from 5000-7500 most of the time. SOMETIMES unload at low as 4300 (at Seeley Lake).

Early on, I had some bogging issues in mid-range, but no DET.
It was rich.
I bought the Fire and Ice intake vents to add.
Rich condition was GONE. It ran so amazing after that.
No bog, still no DET.
Still running stock head.
Holy cow it was fun.
Turned 8700 rpm with my X3.2 track all day long.

I had my sled in the shop in January 2020 for something else, and they did the Polaris factory 2020 ecu reflash AND the BD tune that is supposed to go with it (I think it was 4.02).
It ran ok, but not like it did last spring.

I'm going to test a new updated tune that should be out for download soon.
I've also got the new BD intake vents installed and ready to ride.
I'll share my results here.

What kind of track speed were you seeing at 8700 rpm?
Do you think you are really making more hp and track speed at 8700 than if you had it clutched for 8200-8300?
I'm not trying to be critical, just curious?

 

[Scott]

Have not seen a Dyno myself, so I haven't seen the HP and torque curve for my configuration.
However I do know that when I rev from 8200 to 8700, i feel a strong pickup.

I haven't watched track speed at those RPMs. Too busy watching my line.
It's hard to watch the gauge when 240ish HP kicks in, but I'll try to and then report back to you.
I'll play with that tomorrow.

 

[Scott]

I was climbing Wong's Bowl in McCall this past weekend.
Put a lot of marks on it. With THESE snow conditions...

Held at about 8200. Could see about 45mph track speed.
Pinned it to 8700. Track speed jumped to 52mph.

 

[live2beel]

Scott, how many miles boosted? How much boost are you running? Has it been reliable? Thanks

 

[CaptNCoke]

I’m running a 2020 850, with this years side kick, Idaho head and the latest available tune from BD.
sled rips, pulls hard. An absolute blast to ride. I ride mostly 3-6000 ft, put 2 gallons of av gas per tank with premium non ethanol fuel.
My only complaint is my sled is hard to start when warm, 4-5 pulls with a lot of throttle is common, and the sled runs warmer then a stock sled, a lot warmer In normal conditions, and I over heat really quick in low snow conditions. Kind of frustrating at times.
I am geared down, and running the BD premium clutch kit, MTN tech blow hole kit, slp intake kit as well.
Turbo put on with zero miles, about 650 boosted miles, on original belt.
Throttle response is crisp from the bottom all the way up. It’s way more responsive and pulls a lot harder then 800’s with a BD side kick.
if I can figure out the hard starts, and why it runs a lot warmer, I’ll be an even more happy camper.
After riding this sled, I’ll never go back to a non boosted. It’s way above my riding level, but it’s way too much fun!

 

[mt.sledder]

I was climbing Wong's Bowl in McCall this past weekend.
Put a lot of marks on it. With THESE snow conditions...

Held at about 8200. Could see about 45mph track speed.
Pinned it to 8700. Track speed jumped to 52mph.

I wonder what you would see if you ran heavier weights so your max rpm as 8200. I'm running the TRS clutch kit 8300 with 74 gram weights and have seen a range of 50 to 62 mph track speed however that is with pro gears and they read a little higher. This is also in about 2.5'- 3' of good powder in Revy at 7000'

 

[800dragon_rmk]

Running an sidekick bd kit on my 19 850 with the Colorado head, intercooled, high boost upgrade. 163x3.2 challenger on it. Using straight 100LL. Riding 3-6500 feet. Took me awhile to get it dialed in as the bd recommended clutching was completely off. Had to run 82g weights with their primary spring to get it under 8800rpm. Now that I have did some of my own testing I’m back down to 78.5g with some primary and secondary changes. Bottom end has cleaned right up and it’s as snappy as a stock sled off the bottom. Will pull 70mph track speed up anything. Had very hot clutches initially so installed a MTNK blow hole and haven’t blown any belts. Temps are as cool as stock even without the snowflap. Been running turbo Polaris’s and doos for years and this by far is the best running one I’ve had. Running the newest bd flash and Polaris flash. No hot start issues. Any questions let me
Know

 

[800dragon_rmk]

I wonder what you would see if you ran heavier weights so your max rpm as 8200. I'm running the TRS clutch kit 8300 with 74 gram weights and have seen a range of 50 to 62 mph track speed however that is with pro gears and they read a little higher. This is also in about 2.5'- 3' of good powder in Revy at 7000'

Bd says 8650 +\- 100rpm with there kits

 

[Sheetmetalfab]

Running an sidekick bd kit on my 19 850 with the Colorado head, intercooled, high boost upgrade. 163x3.2 challenger on it. Using straight 100LL. Riding 3-6500 feet. Took me awhile to get it dialed in as the bd recommended clutching was completely off. Had to run 82g weights with their primary spring to get it under 8800rpm. Now that I have did some of my own testing I’m back down to 78.5g with some primary and secondary changes. Bottom end has cleaned right up and it’s as snappy as a stock sled off the bottom. Will pull 70mph track speed up anything. Had very hot clutches initially so installed a MTNK blow hole and haven’t blown any belts. Temps are as cool as stock even without the snowflap. Been running turbo Polaris’s and doos for years and this by far is the best running one I’ve had. Running the newest bd flash and Polaris flash. No hot start issues. Any questions let me
Know

70 mph track speed.

have you checked the accuracy of your speedometer?

 

[800dragon_rmk]

70 mph track speed.

have you checked the accuracy of your speedometer?

Nope does 73 across the field and that fast up a hill so just what the pidd says haha feels fast anyways

 

[mt.sledder]

Running an sidekick bd kit on my 19 850 with the Colorado head, intercooled, high boost upgrade. 163x3.2 challenger on it. Using straight 100LL. Riding 3-6500 feet. Took me awhile to get it dialed in as the bd recommended clutching was completely off. Had to run 82g weights with their primary spring to get it under 8800rpm. Now that I have did some of my own testing I’m back down to 78.5g with some primary and secondary changes. Bottom end has cleaned right up and it’s as snappy as a stock sled off the bottom. Will pull 70mph track speed up anything. Had very hot clutches initially so installed a MTNK blow hole and haven’t blown any belts. Temps are as cool as stock even without the snowflap. Been running turbo Polaris’s and doos for years and this by far is the best running one I’ve had. Running the newest bd flash and Polaris flash. No hot start issues. Any questions let me
Know

How much boost are you running? The last time i was getting consistent track speeds over 70 mph I was running 12 psi and that was several years ago when I had secondary injectors.

 

[800dragon_rmk]

How much boost are you running? The last time i was getting consistent track speeds over 70 mph I was running 12 psi and that was several years ago when I had secondary injectors.

Running 12psi

 

[Scott]

Scott, how many miles boosted? How much boost are you running? Has it been reliable? Thanks

A little over 600 miles boosted. Turbo system has been totally reliable.
Dowloading the most updated tune makes it run like a champ.

 

[Scott]

I wonder what you would see if you ran heavier weights so your max rpm as 8200. I'm running the TRS clutch kit 8300 with 74 gram weights and have seen a range of 50 to 62 mph track speed however that is with pro gears and they read a little higher. This is also in about 2.5'- 3' of good powder in Revy at 7000'

I don't plan to run heavier weights.
I have the BD weights set to turn where they tell me to.

 

[Scott]

BTW, my track speed is based on uncalibrated gear down.

 

[800dragon_rmk]

BTW, my track speed is based on uncalibrated gear down.

Did you ride before the gear down? What do you prefer

 

[Scott]

I had three or four hundred miles before gear down. Went through a couple belts. Had hot clutches.

I prefer the gear down.
Cooler clutches and better bottom end, for sure.
Way better belt life.