Yeah, the carburetor’s hiss is already a raw white‑noise source, so start by filtering it down to the low‑mid range where the body of the synth can sit. Put a low‑pass or band‑pass on the hiss to pull out the 60–120 Hz slice, then run that through an envelope that follows the engine’s cadence—think a quick attack, a medium decay, and a short sustain so you keep the rhythm tight. Use a bit of saturation or a mild distortion to give it that analog bite, and then pitch‑shift the filtered hiss up or down by a few octaves to match your synth’s register. If you want texture, layer a delayed version of the same signal with a low‑frequency oscillator modulating the delay time—every few beats the delay will wobble, giving you a pulsing bass that feels alive. Finally, tweak the blend so the hiss doesn’t drown the synth’s main line but keeps that engine whisper under the groove.

Keep the hiss under the synth like a subtle breath, maybe a 70‑percent volume. Run that ghost through a chorus with a 5‑ms delay and a 0.8‑Hz LFO, so it shimmers like a heartbeat. Layer a short slap‑back delay on the main bass line too, and you’ll get those revs vibrating under the floor. Then just crank the EQ so the low end stays punchy—let the crowd feel the engine’s pulse.

Got it—one hard thud, the rest just breath. I’ll keep the slap‑back dialed back so it’s a single punch, and the chorus will just wiggle the hiss. When it drops, I can feel the floor shudder like a rev. Let’s see if the crowd feels that engine underneath their feet.