ENGINE · 1989-1995
LT5 tuning
LT5 — GM / Lotus-engineered 5.7 NA V8 DOHC (Corvette ZR-1 C4). V8 NA DOHC 32v (only DOHC GM V8 ever), 5.7 L, 375-405 HP stock. Cars: Chevrolet Corvette ZR-1 (C4 1990-1995) — the only model that ever shipped with LT5.
Engine specs
| Engine code | LT5 |
|---|---|
| Configuration | V8 NA DOHC 32v (only DOHC GM V8 ever) |
| Displacement | 5.7 L |
| Production years | 1989-1995 |
| Stock power | 375-405 HP |
| ECU family | GM PCM 7747 (older) → |
Tuning stages on LT5
| Stage 1 | +15-25 HP |
|---|---|
| Stage 2 | +30-50 HP (headers + intake + tune) |
| Stage 3 | +200+ HP (supercharger — uncommon, expensive) |
Conservative real-world estimates. Actual results depend on hardware health, fuel quality, ambient temperature, and the specific calibration written.
Services available on LT5
Common DTC codes on LT5
Brands running LT5
Workshop workflow
- Read the LT5 ECU via OBD or bench using your existing flasher (KESS3, AutoTuner, MPPS, Trasdata, FRF).
- Open Softechpro V5 and drag the .bin / .ori / .hex / .s19 / .frf onto the workspace. The GM PCM 7747 (older) variant is auto-detected.
- Pick the service tab and apply Stage 1 / 2 / 3 / DPF OFF / EGR OFF / AdBlue OFF as required.
- Save patched .bin — the outer CRC is recomputed automatically.
- Flash via your existing flasher. Adaptation reset via OEM scan tool if required.