Cook the pasta in a large pot of salted boiling water for 8–10 minutes until al dente. Drain and rinse with cold water.

Combine the drained pasta with half of the dill pickle juice in a large mixing bowl and toss. Let sit for 5 minutes, then drain excess juice.

In a medium bowl, whisk together mayonnaise, sour cream, remaining dill pickle juice, and Sriracha. Season with salt and pepper.

In a large bowl, combine pasta, cheddar cheese, sliced dill pickles, fresh dill, and white onion. Toss to distribute ingredients.

Pour the dressing over the salad ingredients and fold gently to coat everything.

Cover and refrigerate for 4-6 hours or overnight before serving.