My heads/cam LS1 is underperforming — I still have the stock LS1 intake and stock injectors. What's holding it back?
Likely both. Speedway's point is that heads and cam only pay off when the whole airflow path and fuel system keep up:
- Intake: an aftermarket intake paired with heads and cam "really wakes up" an LS1. The factory LS1 intake — and even the better LS6 or TBSS factory intakes — have limits. Also make sure the intake's port shape matches your heads (cathedral vs rectangle).
- Injectors: more airflow needs higher-flow injectors to match. Stock injectors can run out on a heads/cam combination. Size them with the fuel system calculator.
- Throttle body and exhaust: a suitably sized throttle body and headers/cat-back complete the airflow path.
- Tune: a custom tune for air/fuel and timing is essential after these changes.
Confidence: medium — sources disagree or are limited; check the sources below.
Community discussion
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Sources
- 5.7 LS1 Engine Upgrades: Build Recipes for 400 HP-700+ HP — Speedway Motors