Total Performance Intake Valve

$ 4.00$ 29.95

SUMMER SALE – 50% off

The Total Performance Intake Valve is designed to increase air flow into your air box and carburetors.

Total Performance Intake Valves come in two styles; Knobby and Low-Boy. Choose style, then choose color, then choose quantity.

Order a template (under PACK drop-down) for easy installation of the Low-Boy model.

Replacement filters also available here.


Total Performance Intake Valve

SUMMER SALE – 50% off
from now until July 31, 2024

The Total Performance Intake (TPI) Valve is designed to increase air flow into your air box and carburetors in a controlled manner.

Racers and tuners as well as many trail riders have known for many years that opening up the air box in order to flow more air makes more horsepower. This is usually called “ventilating” or “gutting” the air box. They also know that more air means that the engine will be running leaner exactly the same as installing a smaller main jet.

Only one thing was missing, and that was the ability to go back to the richer jetting required for colder weather or lower altitudes. What did they do about this? They tried to tape or stuff foam rubber in the openings they had created. All of this was very messy and imprecise. Much of the time they were either too rich or too lean or they had to start changing main jets in order to be jetted correctly.

There must be a better way. There is!! It’s called a Total Performance Intake Valve. The TPI Valve can be opened completely to the leanest position or closed completely to the richest position or any position in between.

The Total Performance Intake (TPI) Valve gives you a range of two to four jet sizes of adjustment providing you use the recommended number of valves in your air box.


For more information on airbox modifications, read: Airbox, Friend or Foe?

The TPI “Knobby” Valve is 1 1/2″ diameter and 1 1/2″ high.

The TPI “Low-Boy” valve is a flush mounting version which is 2 5/8″ square overall.

TPI comes with black filters.

Extra filters are available in Black for Knobby and Black and Red for Low-Boy.

A cutting template is available for the Low-Boy Valves.

TPI Low Boy – Adjustable Intake Valves

Speed shops all across the snow belt are delighted with the results they’re seeing installing the new TPI Low Boy adjustable intake valves from Thunder Products.  This tight-clearance version of the adjustable TPI valves first previewed in the September 2002 issue of SnowTech Magazine has proven to be even more popular than the original version.

The TPI Low Boy mounts into the airbox and allows you to open or close the added intake area to provide “air jetting”; more or less air intake surface area with the sliding “gate” on the valve.

The installation of TPI Low Boys into the new MX Z 800 REV airbox provides an increase of up to five horsepower.  They run with the valves open down to about –10 F, close one off at that temp, and close off both valves at –20 F.

We’ve also heard from some mountain riders who have been adding the Low Boy valves to the RX-1 Mountain intake to provide added airflow when the stock intake starts to become restricted with snow.  You can install TPI Low Boys on the cover. This provides an increase in airflow, requiring larger main jets and some other tweaks to compensate, with the result being an engine that is “way more responsive”.

We have also seen excellent results using the Low Boys on the new Arctic Cat twins, integrating the TPI Low Boys into power-up performance packages for many models.

We’ve even found the Low Boy valves to work extremely well on four-stroke dirt bikes; we installed one into the airbox on a four stroke Honda enduro bike and immediately realized more power, easier starting, more tractability, and less stalling.  The possibilities are endless!

Ask for the Low Boy valves at your favorite speed shop or contact Thunder Products directly at 320-597-2700.  They present an attractive option to permanent airbox modifications and provide the tuner with yet another option in increasing the airflow characteristics of the engine.

Technical Articles published on TPI Valve

Knobby Valve

Low-Boy Valve


Additional information

Weight N/A
TPI Valve



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  • Total Performance Intake Valve
  • Total Performance Intake Valve
  • TPI Valves
  • TPI Valves
  • TPI Low Boy Adjustable Intake Valves
  • Total Performance Intake Valves
  • Total Performance Intake Valves

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