About Rennen ITB’s by JSR

Precision engineering for air-cooled Porsche 911 performance

Rennen ITB’s by JSR specializes in the design and manufacture of high-performance Individual Throttle Body (ITB) systems for air-cooled Porsche 911 engines. Our Elliptical Roller Barrel throttle bodies represent the pinnacle of precision engineering, combining advanced design with meticulous craftsmanship.

Every component is CNC machined from EN-AW 6082-T6 aluminium and finished with a durable hard anodized coating. This ensures not only exceptional performance but also long-lasting reliability under the most demanding conditions.

Our Engineering Excellence


Precision Manufacturing

All parts are CNC machined from high-grade EN-AW 6082-T6 aluminium to exact specifications.


Tapered Throttle Bodies

Optimized taper from air horn to cylinder head maximizes airflow efficiency.


Hard Anodized Finish

Durable hard anodized coating provides superior wear resistance and corrosion protection.


Complete Systems

Every system includes throttle linkage, rod ends, and fuel rails - ready to install.


Elliptical Roller Barrels

Our unique elliptical roller barrel design ensures smooth, progressive throttle response.


Custom Solutions

We offer custom bore sizes and configurations to match your specific engine build.

Performance You Can Measure

Our ITB systems have been proven on the dyno time and time again. Customers consistently report significant power gains, improved throttle response, and that unmistakable sound above 4,000 rpm that makes the air-cooled Porsche 911 so special.

Whether you're building a street car, a track weapon, or a full race engine, Rennen ITB’s by JSR systems deliver the performance and reliability you demand. Our systems are compatible with engine sizes from 2.7 to 4.0 liters, with options for both 2-stud and 3-stud cylinder heads.

Let's Build Something Special

Contact us to discuss your project. We're here to help you achieve your performance goals.