I have an intake, chip and exhasut. I have run a few Z28's, none that were heavily modded. I didn't lose to any untill I was past 4th gear. My shift into 5th is where I the Z28's start to catch up. I raced a 1999 Z28 with a moded exhaust, and intake. I had 4 people in my car vs. his 1, and we still were head to head untill 4th gear. I say about 90mph is where the z28 starts to pull on my car. Later Chris