The FAST innovative manifold system that features interchangeable runners that allows you to move the power band to what is perfect for your application.
The amazing thing about the new FAST intake was the ability to adjust the runner length and tune the intake to the needs of your specific engine combination. Long runners make more power at lower engine speeds, while short runners enhance power production higher in the rev range. Displacement and cam timing also play a big part in which runner length works best.
FAST Adjustable LSXR Intake
Long vs. Medium vs. Short
For the test on the three different intake runner lengths that the longest runner (blue) offered the best average power up to 6,500 rpm. In truth, the results were not surprising given that the test engine was a stock LS3 with a cam. We all know how well even the stock (long-runner) LS3 intake does in this rpm range, to say nothing of the original 102mm FAST LSXR.
FAST didn’t design the medium and short runners for stock or mild applications (they had that covered), but rather for the high-rpm and/or increased displacement applications. It is nice to know that with a simple runner change, the effective operating range of the intake can be adjusted to suit your performance needs.