GPI Gen 5 LT VVT Phaser Limiter Plug Only - 4 Degree Lockout (2022 LT1 / L86 / L83 | 2020 - 2024 Corvette C8) - SLUG4-2022
4° Phaser Limiter Plug for 2022+ LT Engines & C8 Corvette
The GPI SLUG4-2022 Phaser Limiter Plug provides a controlled 4-degree lockout for Gen 5 LT engines, including the 2022 LT1, L86, L83, and 2020 - 2024 C8 Corvette. This plug-only option is designed for shops and builders who already own the dedicated GPI phaser tool and spring lock tool. Limiting phaser travel to 4 degrees helps stabilize camshaft control - crucial for aftermarket cam installations and high-RPM durability.
The Gen 5 LT Cam Timing Problem
Through extensive testing during countless LT cam installs, GPI identified a recurring issue: unpredictable and excessive camshaft timing movement at higher RPM and elevated oil temperatures. The symptoms observed include:
- Uncommanded cam timing retard
- Discrepancies between commanded vs. actual cam position
- Worsening timing drift as oil temperatures rise
- Up to 8 - 10 degrees of unintended cam retard
- Noticeable drop in top-end power after repeated pulls
These issues are especially problematic for performance builds where piston-to-valve clearance and precise timing control are critical.
The GPI Solution: 4° Controlled VVT Movement
The SLUG4-2022 limiter plug restricts phaser travel to a safe 4-degree window, eliminating the uncontrolled timing sweep that plagues Gen 5 LT engines. This limited range maintains drivability while offering enough cam authority for performance applications.
- 4° maximum cam phaser movement
- Prevents uncontrolled timing retard at high RPM
- Improves stability for aftermarket performance cams
- Directly addresses power loss at high temperatures
- Crafted specifically for new-generation LT engines and C8 Corvette applications
How Gen V VVT Works
Gen 5 variable valve timing uses ECM-controlled solenoids and oil pressure to advance or retard the camshaft. While excellent for stock fuel economy and power delivery, the wide factory VVT window creates challenges when aftermarket cams are installed:
- Limited piston-to-valve clearance
- Unpredictable VVT movement under heat
- Difficulties achieving precise tuning
With the SLUG4 limiter in place, builders gain predictable VVT behavior and improved tuning consistency.
Performance Highlights
- 4-degree limiter for controlled VVT operation
- Stabilizes cam timing in high-RPM and high-heat conditions
- Compatible with 2022 LT1/L86/L83 and 2020 - 2024 C8 Corvette
- Ideal for performance camshaft upgrades
- Plug-only version for experienced shops and builders
Quick Specs
- Compatibility: 2022 LT1 / L86 / L83, 2020 - 2024 C8 Corvette
- Limiter Range: 4 degrees
- Included: Phaser limiter plug only
- Tools Needed: GPI phaser tool & spring lock (not included)
- Part Number: SLUG4-2022
FAQs
Why would I choose a 4-degree limiter instead of a full lockout?
Some camshafts and tuning strategies benefit from retaining limited VVT movement. A 4-degree limiter offers excellent stability while preserving drivability and low-end response.
Is this plug compatible with the C8 Corvette?
Yes. The SLUG4-2022 is specifically designed to support 2020 - 2024 C8 Corvette valvetrain architecture along with the 2022 LT1, L86, and L83 platforms.
Why Buy from Beefcake Racing?
Beefcake Racing offers expert guidance and proven LT valvetrain components. Whether you're dialing in a street-friendly cam or building a high-RPM track setup, our team ensures you get the right parts the first time.
Call 1-855-827-7223 or email sales@beefcakeracing.com.
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