TECH NOTES
No forum folklore. Just the numbers.
Real problems from the aftermarket, worked through in detail — no product required to read them.
RPM & Signal Conditioning
TACH-SIG-01 · READ: 7 MIN
Is a Pull-Up Resistor Enough for an LS Swap Tach Signal?
Why a bare pull-up resistor wires your PCM's tach output directly to the dash harness, and what a proper signal conditioner does differently.
SIG-TYPE-01 · READ: 7 MIN
Why Coil Negative, Coil Positive, and Square Wave Aren't Interchangeable
Three genuinely different tach signal families, and why a "universal" adapter tuned for one of them only ever half-works on the other two.
Power Switching & PWM
PWM-FREQ-01 · READ: 6 MIN
What Frequency Should You Run for Holley PWM Fuel Pump Control?
Why the standard 20–50 Hz tuning recommendation is hard on pump motor windings, and what a hardware translation layer fixes.
PWM-GEN-01 · READ: 7 MIN
Do You Need PWM at All? Pumps, Fans, and Why It's Worth the Trouble
What PWM actually is, and the concrete reasons it helps a pump (fuel heating, aeration, longevity) and a fan (inrush current, noise) — plus when a relay is the better call.