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Exhaust Systems Polaris® RZR Pro XP®

Print Instructions

HMF Racing Big Core (Turbo Back) Exhaust Instructions

For Models: RZR Pro XP® (2020-2022)


!!! WARNING !!! Before working on your machine, make sure it is parked on a level surface with the transmission in park and/or the parking brake engaged.

Do not work on any machine with a hot engine or exhaust.  Allow time for all parts to cool in order to reduce the risk of burns.

Blackout Exhausts: Take care not to get grease or oils on the exhaust.  Cleaning our Blackout exhaust with harsh solvents, abrasives, or pressure washers will remove the coating and is not covered under warranty.

1. Remove the plastic fascia covering the original silencer.(See Figure #1)

Big Core (Turbo Back) Exhaust Instructions - Figure 1

2. Remove the heatshields around the turbocharger and downpipe.

3. Disconnect and remove the oxygen sensor from the original downpipe.  Set the sensor aside for installation later.

4. Remove the (3) nuts securing the downpipe to the silencer.(See Figure #2)

Big Core (Turbo Back) Exhaust Instructions - Figure 2

5. Support the downpipe near the (3) bolt flange using a bungee cord or similar method to keep it from falling down when the silencer is removed.

6. Using a spring puller, wire, or rope remove the (2) springs securing the silencer to the frame.  Carefully remove the silencer from the vehicle.  Remove the triangular rubber grommets from the frame.  

7. Using a 6mm allen socket remove the (4) bolts securing the downpipe to the turbocharger.(See Figure #3)

Big Core (Turbo Back) Exhaust Instructions - Figure 3

Tip: Spray down the (4) downpipe to turbo bolts with penetrating oil before attempting to remove them.  Allow the solvent to soak in for about an hour, don’t forget to clean up any solvent before starting the engine.  These bolts are notorious for seizing in the turbocharger. New bolts are provided with the exhaust.  If the threads in the turbo appear to be slightly damaged, use a thread chase to repair minor damage (M8-1.25 threadpitch).

8. Remove the downpipe from the vehicle being careful not to lose the metal gasket between the downpipe and turbocharger.  This gasket will be reused during installation.


1. Line up the downpipe to turbocharger gasket and install the HMF downpipe using the provided (4) M8-1.25x20 Allen Bolts.  Do not tighten the bolts at this point. (See Figure #4)

Big Core (Turbo Back) Exhaust Instructions - Figure 4

2. Loosely install the provided bracket on the frame tube using the provided (4) M6-1.0x20 Allen Bolts for the tube clamp.  Do not tighten.(See Figure #5)

Big Core (Turbo Back) Exhaust Instructions - Figure 5

3. Slide the silencer onto the downpipe aligning the silencer’s brackets with the previously installed bracket. 

4. Loosely secure the silencer to the bracket using the provide (2) M10-1.5x40 Hex Bolts, (2) M10-1.5 Nylock Nuts, (2) 3/8” Flat Washers, and (4) 3/8” Fender Washers.  Place the larger fender washers on either side of the pre-installed rubber grommets.(See Figure #6)

Big Core (Turbo Back) Exhaust Instructions - Figure 6

5. Check for proper alignment and ensure no parts are binding.  Tighten hardware in the following order:
a. (4) Downpipe to turbocharger allen bolts
b. (2) Silencer to bracket bolts
c. (4) Allen bolts for the tube clamp bracket

Note: Do not overtighten the tube clamp bolts.  There will be a gap between the two halves.  Tighten the bolts evenly to create an even gap. 

6. Install the provided (2) Long Neck Springs between the downpipe and silencer using a spring puller, wire, or rope. 

7. Install the provided heat shield square where the plastic is closest to the silencer.

8. Reinstall the heatshield around the turbocharger using the original hardware.

9. Reinstall the oxygen sensor and plug it back into the wiring harness.(See Figure #7)

Big Core (Turbo Back) Exhaust Instructions - Figure 7

10. Reinstall the rear plastic fascia using the original hardware if desired.

Wipe off any fingerprints or markings using a soft cloth and mild detergent such as soap and water or glass cleaner without ammonia.  Once the exhaust heat cycles any oils left on the exhaust may permanently imprint.

If you received a stainless steel exhaust without the Blackout coating it is normal for the pipes to change color as they heat cycle.

The HMF Blackout exhaust will smoke and put out an odor for the first full heat cycle as the coating goes through its final curing process.  It is recommended to allow this process to happen in a well ventilated area.

All systems will produce a smoke out the end cap after a short initial heat cycle, this is the packing material bedding in and is completely normal.(See Figure #8)

Big Core (Turbo Back) Exhaust Instructions - Figure 8


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