I got my Tanabe Y pipe from my favorite UPS truck this morning so I immediately got to work getting rid of that nasty stock pile of restriction and in with the beautiful new Y pipe. The car already has Berk HFCs installed so this mod was more to tie in the HFCs to the rear of the exhaust because I personally believe the largest restrictions in the OEM exhaust are the factory cats and the Y pipe.
After the stock Y pipe was removed, I didn't realize that the Berk outlet diameter was almost an inch larger than the oem Y pipe so that was killing my gains. The exhaust diameter in the OEM piece also had varied diameters, the smallest point of the Y pipe measured 1 1/2"!
My measurements for the inlet and outlet diameters of the stock Y pipe are as follows:
Cat to Y pipe: 1 3/4" for both inlets of the OEM y pipe
Y pipe to axle-back: 2 1/2"
Tanabe Y Pipe diameters:
Cat to Y pipe: 2 1/4" for both inlets
Y pipe to axle-back: 2 3/4"
Just to make a point, the diameter of the inlets for the Tanabe Y pipe match the Berks... Now look at that restrictive OEM piece.
Comparison of the two at the smallest point of the OEM Y pipe:
And Installed:
In Car Conclusions:
With the ECU reset and the Tanabe Y pipe in, I felt a huge jump in power not only in the top end, but mostly the mid-range. The car just pulls so hard now that I feel the exhaust is very well rounded with the exception of the rear muffler section. The sound actually changed more than I was expecting; the tone is much deeper and less raspy, adding a bit of volume past 4k rpm. However, the exhaust is still fairly quiet under 3k rpm which is great for those who are interested in being low key when cruising but really letting the car sing up top. Fit and finish was excellent as well with nice welds and a very smooth merge at the end of the Y pipe.
I highly recommend the pairing of HFCs with an upgraded Y pipe for those that want to get rid of the two most restrictive areas of the OEM exhaust. Videos to come later!