Blacktop ITBs on a Silvertop: Complete Conversion Guide
Want better throttle response from your 4AGE? Installing Blacktop ITBs on a Silvertop is a proven way to do it. The stock Silvertop setup relies on an AFM, limiting your ability to run open throttles. But with the right changes, you can switch to a MAP sensor and open up performance gains.
Let’s break down how this conversion works, what parts you need, and why it makes such a difference.
Why Run Blacktop ITBs on a Silvertop?
Silvertop 4AGE engines use a Mass Air Flow (MAF or AFM) sensor. This sensor must measure air before it enters the engine. As a result, running open throttles is not possible with the stock ECU.
On the other hand, the Blacktop 4AGE uses a MAP (Manifold Absolute Pressure) sensor. It reads vacuum pressure from behind the throttles. This allows you to run open trumpets and get that crisp, responsive throttle feel.
By installing Blacktop ITBs on a Silvertop, you bypass the limitations of the AFM system.
Differences Between Silvertop and Blacktop ITBs
Here’s what sets them apart:
- Sensor Type: Silvertop = AFM, Blacktop = MAP
- Vacuum Ports: Blacktop ITBs include built-in vacuum ports for MAP
- Throttle Size: Blacktop ports are around 5mm larger
- Physical Fitment: Both ITBs share the same bolt pattern
- Gaskets: Use a Blacktop gasket for proper sealing
- Airbox Compatibility: Silvertop airbox won’t fit on Blacktop ITBs
How to Install Blacktop ITBs on a Silvertop
- Mount Blacktop ITBs on the Silvertop head. The bolt pattern matches.
- Use a Blacktop gasket to ensure proper port alignment and seal.
- Install a MAP sensor with vacuum lines from the ITB ports.
- Add an Intake Air Temp (IAT) sensor to replace the AFM’s air temp reading.
- Swap to a Blacktop ECU, or use a standalone ECU if tuning is planned.
- Use a conversion harness to adapt the Blacktop ECU to the Silvertop loom.
- Double-check wiring, vacuum routing, and TPS calibration.
Performance Tips After the Swap
- Port-matching the intake side of the Silvertop head to match the larger Blacktop ITBs can help flow.
- You may need to tune the ECU after installation, especially if running a standalone unit.
- Open trumpets need filtration—consider mesh filters or air horns with socks.
- Enjoy the aggressive sound and improved throttle feel!
Final Thoughts
Installing Blacktop ITBs on a Silvertop transforms your 4AGE. It removes airflow restrictions, increases throttle response, and prepares the engine for more aggressive tuning. Yes, it takes effort—but the performance gains are worth it.
Have photos or a build log? Share them and inspire other 4AGE fans!
