12.25" FULL open  top 

TBS XR Race Inserts are crafted from billet aluminum in an array of sizes.  Meant to change when boost is activated, a smaller opening boosts quicker and a bigger opening produces more boost on the top end.  A quick way to tune your blower at the track, these inserts are available only for the race series blowers.

Available in:

• 11"
• 10"
• 9"
• 8"
• 7"
• 6"
• 5.5"
• 5.35"
• 4.50"

Description

TBS XR Race Inserts are crafted from billet aluminum in an array of sizes.  Meant to change when boost is activated, a smaller opening boosts quicker and a bigger opening produces more boost on the top end.  A quick way to tune your blower at the track, these inserts are available only for the race series blowers. With the understanding that all race applications and engine combinations are different, it  is not a "one blower fits all" industry anymore.  In the early years, blowers were being custom built for specific applications.  This process was not only expensive but also time consuming.  With this understanding,  TBS found the need for interchangeable inserts to allow for easy customization of the inlet opening of the supercharger.  Incorporated into all TBS Race Blowers, the use of a TBS Insert now allows you to tailor your blower boost to your specific application.  By changing the inlet opening of the supercharger, it allows you to better match blower boost to the fuel curve or track conditions. The larger openings will result in higher boost and efficiency at higher RPMs.  Meanwhile, the smaller openings will result in increased boost down low, but will start to restrict the air flow at the top end.  Now you, as the tuner/racer, have a choice on how the blower needs to work and won't be stuck on what the manufacturer feels you need.