This customer wasn’t satisfied with the audible knock he had from his previous overzealous tuner. He drove in from Virginia and we installed our Purple Belt Performance Package. This car now makes 491 whp and 518 wtq on 93 octane pump gas and 597 whp and 551 wtq on E46 fuel. Best of all, the tune is safe and solid, with no knock whatsoever. We do it right.