Originally Posted by semtex

Are you referring to the HKS Legamax muffler? If so, I don't think you'll get much of a gain. If you're looking for a good gain, try the HKS Hi-Power cat-back exhaust. In any case, there's a thread for the Legamax. I don't know if you've seen it yet. HKS LEGAMAX Premium muffler for 370Z will be released later this year