Welcome.

Welcome to Bristol Core. We are an American manufacturer specializing in muffler packing for motorsport.

What we do...

If you are a rider or builder looking for high quality material to pack a muffler with, you've come to the right place.

Off road riding can be torture on muffler packing. We offer packing kits and materials designed for the heat and revs of two stroke (RaceTEX) and four stroke (Spec 19) motocross, ATV, UTV and adventure bikes.


Riding a big twin and need to repack? Maybe your muffler is getting too loud and what originally sounded great has developed a sharp "crack" sound.
You can rely on our high-end SPEC 19 for a packing system that will hold up to many, many miles of riding.

Sportbikes with aftermarket mufflers sound awesome, until the packing blows out and it starts sounding like a big empty tin can. We can help you restore the rip and roar with materials that will last.

If you need some assistance deciding what materials or kit will work best for your application, feel free to either call us at (585)-919-0302 or send an e-mail to info@bristolcore.com. We're available Monday through Friday 8am to 5pm Eastern.




Spec 19 15" Four Stroke Universal Kit RaceTEX 16" Two Stroke Universal Repack Kit
Price: $22.95
Sale Price: $19.95
You save $3.00!
more info
Price: $19.95
Sale Price: $14.95
You save $5.00!
more info
Spec 19 15" Four Stroke Universal Kit RaceTEX 16" Two Stroke Universal Repack Kit
FITMENT - This pillow will fill a four stroke muffler with a shell up to 4.25" in diameter (13.3" in circumference) and up to 15" in length including the end-caps if they are packable.

Cut to length pillow design utilizing our newest high temperature packing material for up to 1500F continuous duty.
Designed for extreme duty four stroke temperatures.
Compressed pillow designed for easy installation.
Contains 575 grams of Spec 19 packing material
FITMENT INFO - This packing kit will fill a silencer up to 16" long (including packable end-caps) with a shell circumference of 8" -10". This is NOT recommended for larger volume 2-stroke silencers, for example - current Yamaha, FMF 2.1, FMF Q Stealth - look for PN 14709

Pillow designed with adhesive tape flap for keeping it rolled tight during installation. Main pillow can be trimmed for mufflers shorter than 16" Kit contains two cap stuffer pillows. Easy to follow installation instructions. Long lasting muffler packing material. 100% Made In The USA Applications This kit can be used to re-pack any rebuildable muffler with dimensions that fall within those listed under Technical Specifications including mufflers for motocross, ATVs, UTVs, sport, touring, adventure and big cruisers.
RaceTEX 16" XL Two Stroke Universal Repack Kit Spec 19 19" Four Stroke Universal Kit
Price: $19.95
Sale Price: $14.95
You save $5.00!
more info
Price: $24.95
Sale Price: $19.95
You save $5.00!
more info
RaceTEX 16" XL Two Stroke Universal Repack Kit Spec 19 19" Four Stroke Universal Kit
FITMENT INFO - This packing kit will fill a silencer up to 16" long (including pack-able end-caps) with a shell circumference of 11" to 12". Examples are FMF 2.1's, FMF Q Stealth, '11-20 YZ 250. This is NOT recommended for smaller volume 2-stroke silencers, look for PN 14567.

Cut to length pillow design utilizing our newest high temperature packing material for up to 1100F continuous duty.
Long lasting two stroke packing.
Compressed pillow designed for easy installation.
Contains 450 grams of RaceTEX packing material.
FITMENT - This pillow will fill a four stroke muffler with a shell up to 4.25" in diameter (13.3" in circumference) and up to 19" in length including the end-caps if they are packable.

Cut to length pillow design utilizing our newest high temperature packing material for up to 1500F continuous duty.
Designed for extreme duty four stroke temperatures.
Compressed pillow designed for easy installation.
Contains 725 grams of Spec 19 packing material