The diverter valve (DV) spacer, a simple modification designed to enhance the sound of turbocharged engines, has garnered a reputation for causing boost leaks. This article investigates these claims, examining the spacer’s design, analyzing performance data, and ultimately debunking the myth of inherent boost leaks caused by DV spacers.
Examining the Diverter Spacer Design
The DV spacer is a straightforward component, typically constructed from metal with O-rings to ensure a tight seal against the turbocharger housing. Its primary function is to relocate the diverter valve piston, altering the airflow path and creating a more pronounced whooshing sound when the valve releases pressure.
A detailed examination of a typical DV spacer reveals flat mating surfaces designed to flush-mount against the compressor housing, further reinforced by the O-ring seals. This design aims to prevent any unintended air leakage. The spacer also incorporates a well for the DV piston to sit within, seemingly improving the seal compared to the flat surface of the turbocharger housing.
Visually, the DV spacer exhibits no inherent design flaws that would predispose it to boost leaks. The robust construction and sealing mechanisms suggest a component designed to maintain pressure integrity.
Data Analysis and Boost Leak Investigation
To further investigate the claims of boost leaks, real-world data was collected and analyzed. Boost pressure curves were recorded with both a stock diverter valve and a DV spacer installed.
The data reveals no discernible difference in boost pressure between the two configurations, indicating that the DV spacer is not causing a measurable boost leak. Fuel economy also remained consistent, contradicting anecdotal reports of significant drops in MPG. Further comparisons using a GFB DV+ in conjunction with the stock DV also confirmed consistent boost pressure maintenance with the spacer installed.
Reinterpreting Diverter Valve Behavior
While the data disproves the theory of spacer-induced leaks, another explanation for the perceived boost loss emerged. Data logs revealed that the engine control unit (ECU) frequently opens the diverter valve during steady-state cruising and even during moderate acceleration.
This unexpected DV behavior, venting air at seemingly inappropriate times, can easily be misinterpreted as a boost leak, particularly when accompanied by the audible whoosh of a DV spacer or aftermarket blow-off valve (BOV).
Conclusion: The Diverter Spacer Exonerated
The evidence strongly suggests that the DV spacer is not inherently prone to causing boost leaks. The perceived boost loss often attributed to the spacer is more likely a result of the ECU’s complex diverter valve management strategies, misinterpreted as a malfunction. The DV spacer, designed for sound enhancement, appears to function as intended without negatively impacting performance. The myth of the leaky Diverter Spacer is debunked.
