Aftermarket Assassins 2022-Up Pro-R 4 Cylinder Stage 4 (275 HP) Lock & Load Kit **2-5 Day Lead Time**


Aftermarket Assassins

  • $ 3,200.00
  • Save $ 40

Customizations Total: $ 0.00

Lock and load your Polaris Pro R 4 cylinder and get ready for some serious kick!  The Pro R is an awesome machine, but Polaris left a ton of room for improvement on the table.  This simple kit is the best way to wake up your Pro R as it comes with our proven ECU flash. The ECU flash adds some amazing horsepower from low end to high end RPM and really gives your machine that "snap" you're looking for.  Our AA Stage 3 clutch kit compliments the tuning perfectly by more efficiently transferring power to the wheels and ridding yourself of the very lazy factory clutching setup and poor belt grip.  We finish out the kit with our AA RZR Pro-R full exhaust (head pipe and muffler) and it's just what your machine needs!  We set out to produce an exhaust that looks great, sounds great and has adjustable sound levels while producing the most power possible.

  • Kit includes AA stage 3 ECU flash for 2022-Up RZR Pro R 4 Cylinder Models **Requires ECU to be sent in for programming** , AA Stage 3 Clutch Kit with primary clutch limiter and butter shift washers, AA Stainless Full Exhaust (head pipe & muffler), and Brian Crower High Performance Stage 2 Cams.
  • BC "Drop In" camshafts work extremely well, but especially well above 8400 RPM.  This comes into play for all types of riding, but especially those riding faster pace and/or dunes riding.  Running at 8500-8700 RPM works well in these situations.  
  • Cams are drop in, but valve clearance still should be checked and adjusted with new buckets as needed.  
  • Works with all models including ones with Dynamix and/or EVAP models.  
  • Looking for the best/most badass ECU tuning available for your RZR Pro R?  AA's performance tunes are now available to gain horsepower and torque.  Through our advanced ECU tuning we are able to modify parameters correctly to gain you the power needed.  We are highly experienced in tuning RZRs and this will show.
  • The Pro R uses a new Bosch MG1 ECU.  Currently no programmers like the PV3 are available and no ETA, so sending your ECU in for a bench flash is the only way to get a great tune. 
  • Big horsepower gains (see tune descriptions below for more details)
  • Much quicker throttle response and power delivery giving a whole new feel to the vehicle
  • Throttle by wire limiters disabled
  • Fan on/off at 185 degrees Fahrenheit (Stock is 190) which is just above the thermostat opening temp.  The progressive fan also ramps up quicker to keep you running cooler than OEM. 
  • Speed limiter removed in low and high gears (Most will be able to run over 100 MPH!)
  • More throttle % in low gear and reverse
  • Rev limit at a safe 8800 RPM (stock is 8650).  Ideal peak RPM is 8500-8600 with the flash and cams, but 8800 is for ramp up overshoot/top speed.
  • AA's wicked timing curve is safe for the fuel used, but we do a much better job of finding timing limits for ramp up/more torque.  Many others simply focus on wide open throttle timing/fueling.
  • AA's modified fuel curve will still get decent mileage cruising, but is corrected over the factory lean AFR when needed. 
  • AA muffler is now available with an electronic cutout option to adjust sound on the fly without having to install or remove a quiet cap. 
  • Included Level 3 Tune:  This tune is developed for a Pro R with our aftermarket exhaust and Brian Crower High Performance Stage 2 Cams on 91-93 octane.  This tune adds +29 RWHP peak and a massive +33 RWHP at 45 MPH (This is gaining roughly +40 crank horsepower) putting you at roughly 265 crank horsepower!  Our included Stage 3 clutch kit with this tune really helps the belt to grip and to help drive the extra power to the wheels.
  • If you're unsure if your Pro-R is an EVAP model or not, check your Emissions Control sticker located on the front driver's side frame rail above the master cylinder. See pictures for location.
  • *** ECU MUST BE SENT IN FOR PROGRAMMING:  Aftermarket Assassins, 2348 75th Ave, Osceola, WI 54020  ***
  • The ECU is located behind the passenger (rear passenger if 4 seat) seat. Remove the top panel behind the seats, then remove the fabric panel to expose the ECU.  Remove the torx bolts and ECU connectors.
  • Customer is responsible for shipping to AA, a shipping label is not included in the price
  • Programming turnaround will vary, but is normally 1-2 days. 
  •  Express ECU service for US main 48 states only.   We'll send you a next day UPS label, and ship your ECU ONLY back via next day.  All other pats will be shipped ground unless otherwise specified/selected during order checkout.  Keep in mind we cannot guarantee same day programming or control UPS shipping times/delays.  We will do everything possible to turn the ECU around as fast as possible.
  • When the ECU arrives we'll read your stock file to determine if it's an Evap model or standard, and we'll keep a file folder for your stock/tune files. We'll then flash with the correct AA tune.  
  • If you ever need to go back to the OEM  tune we charge $95 which includes shipping back to you (shipping back for lower 48 US only).  Please contact us if you need to go back to your OEM tune.  
  • MAKE SURE you insure your ECU for $700.  AA is not responsible for shipping delays or lost ECUs. While more expensive over Priority Mail or FedEx, UPS has been the most reliable carrier in our experience. 
  • While express shipping is available on the ECU, express shipping is NOT available for the other items in this kit (the shipping you select in your cart).  To safely ship these parts, they must go into 2 separate boxes and shipping will only calculate for one box.  If you need the rest of the parts expressed, please message us first. Please note the 5-10 day lead time for production/assembling/kitting of these items.
  • Why AA tunes over others?  We have been tuning UTV's with CVT clutches for a long time, longer than almost anyone in our field going back to the 800 RZR.  Tuning a CVT vehicle properly is not an easy task as you have so many variables at one time.  We spend the time to wheel dyno(with actual UTV tires) correctly per modification, and have advanced ECU calibration and clutching knowledge to do so. Every change in horsepower can result in us changing clutching several times. We also develop most of our supporting mods so we know everything works correctly, and build parts to fit the vehicles needs.  Lastly and honestly the most important; we then back up our results with real world data logging on local trails and our facility on 110 acres.  It's this combination that truly makes the difference and why AA normally has a faster vehicle with the same or less rated tune horsepower.   We left nothing on the table on the Pro R bolt-on parts, if others claim more power/gains for the same mods use caution in believing it! 
  • If you have any other needs in these tunes, or any concerns; please e-mail!
  • We offer two clutch kits:   
  • Standard Load:  The Standard Load clutch kit is meant for stock or near stock size  tires and is the one for most fast pace riders or racers. If crawling  with a 2 seat model on 34-35" tires we recommend the High Load setup.  You'll sacrifice some acceleration but have much better low end belt  grip for less belt slip.         
    • 2 Seat Models: 32-35" dirt tires or 30-32" paddles
    • 4 Seat Models: 32-33" dirt tires or 28-30" paddles
  • High Load: The High Load clutch kit is meant for those with larger tires or riding style is mostly low speed crawling         
    • 2 Seat Models: 36"+ dirt tires or 33"+ paddles
    • 4 Seat Models: 34"+ dirt tires or 32"+ paddles
  • Stage 3 Clutch Kit includes: AA Recoil magnetic adjustable clutch weights, setup/installation sheet, primary spring, AA secondary helix, secondary spring, butter shift washer/shim for increased spring preload and less spring harmonics
  • We highly suggest our Revolver Billet Clutch Cover with Tower Lock to strengthen the clutch and provide more airflow for even better cooling
  • The only special tool needed with our clutch kit is our Compression Tool #1
  • Follow this link for more information on our Stage 3 Clutch Kit
  • Follow this link for more information on our full exhaust system: Stainless Head Pipe & Stainless Slip-On Exhaust
  • Follow this link for instructions on how to locate/remove ecu 
  • Oh... and get ready for your Pro R to flat out rip!