Quote:
Originally Posted by Montaver
AFAIK the US spec 718 has the same exhaust restriction as they didn't want to have different engine tunes for different exhaust back pressures. It basically has a some differences to the interior construction of the filter, but I havnt seen a definitive answer. The 718 exhaust valves also stay closed for noise regs in the lower rev range (until around 4k). The 718 still has a fantastic induction sound but a much quieter exhaust compared to the 981 (which is loud and absolutely glorious). Luckily the GPF style section on USDM cars is not emissions monitored so it can be removed. Soul, Fabspeed etc. all have versions of the over axel pipes which remove the restriction.
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You are correct on the OPF/GPF, mostly the same but not monitored. I have Akrapovic over axel pipes on the way and they were cheaper than both SOUL and Fabspeed’s stainless steel pipes. They open up a lot of sound. Otherwise, even stock the car sounds absolutely glorious - induction, engine, and exhaust sound through the range is nothing short of incredible, albeit a bit quiet.