Yep, I went through two engines in my Lightning (in 25000 miles)... same noise. :( Never raced it either. Luckily, they were both replaced under warranty. On the 3rd engine, I said F*CK IT!!!! I put every bolt-on I could find on it. Had it at about 504RWHP. Damn thing ran like a top. 15,000 HARD...