I just installed the custom made polished SS front pipe to my HKS midpipe. I took a drive and was shocked what a difference removing the precat can make. It was a lot louder too. Excellent pull between 2000 to 4500 RPM But on second gear at about 5000 RPM the car started jerking and almost cuting off-- like something was preventing it from reving. I was quite dissapointed as this cut my power down and slowed me from reaching the magic 7K fast. Is this the boost cut or what? I have just ordered for a Greddy BCC.