Ive read alot of threads stating there wasnt much performance gain in aftermarket exhaust for the lexus v8s in the gs 430 and gs 460,possibly because they are not true duals? I see the dyno #s posted on the isf a/m exhaust and they seem significant. I know the gs motors are not as performance orientated,or they have been ecu detuned for smooth power?

Im wondering if a exhaust cutout would be more beneficial for this type of car,Dont think many lexus drivers want a loud car.but it would be nice to have a elec cutout you could use for spirited driving once in a while. Where would be the best location to place a cutout with these motors,I know exhaust velocity and backpressure come into play doing things like this in order to achieve the best power?