Originally Posted by LastResort
You'll make a number of people happy with this idea, as it's been asked a number of times. Really, I think it's quite a trick idea, giving you streetability of a cutout, plus additional performance.
quiet manners on the street, whenever you're not at max boost and the ewg is venting. very similar to the cutout-equipped car with a nice quiet axleback and a cat still in the pipe.
at wot you get BETTER VE gains than the cutout car since you are not only dumping to atmosphere, you're doing it from BEFORE the turbo hotside.
otoh, you would still give up SOME performance by having the turbine gasses pass through the "restrictive" turboback exhaust (that the cutout does not do), since the turbo shaft's energy is a function of mass flow rate and pressure differential across the turbine, and one would assume that there is some additional pressure seen at the turbine outlet. then again, all of the wastegate gasses are subtracted from that post turbo exhaust pipe, so that acts to reduce the pressure seen there. it's probably close to a toss-up.
I suppose this would also address boost creep issues, as those only happen at WOT, correct?
the vta ewg def. takes care of that, whereas putting a cutout on a creeping car is going to make it worse.