In my case stacking was too complicated. I was worried about blowing up my engine while getting the fuel system, cooling and tune dialed in. Not to mention, the power gain wasn't worth the trouble or risk IMO. The faster you spin the supercharger (stacked) the farther out of it's efficiency zone. Therefore if you make 4 lbs of extra boost (stacked) it takes a lot of the additional power to spin the supercharger and your IAT's go up taking away more power as well. I saw very little gain at the 1/4 mile. I ran an ever so slightly faster time when I cooled the car for hours but at a slower mph. The hot lapping I did that night was a touch slower than with just the 178. So, the 1/8 was faster, 0 to 60 faster, but the 1/4 was the same without sitting with ice on the motor for an hour. I only ran the one night stacked. I decided it wasn't worth the risk and it wasn't going to speed me up in the racing that really matters to me. Based on my one night stacked, at sea level, with and without ice, driving 1 1/2 hours each way to the track my conclusion was. From red light to red light the instant power felt great. The boost was huge at 14.7 AFR's, not being tuned for such high boost at part throttle the engine was in danger. It would cost a lot of money and time to get it right. Do what you want. The differing opinions are partially due to the differing usage of our cars and differing altitudes. I'm sure there's more but I've said enough already. It's your decision. If you don't know what your doing, stacking the pulleys is going to be risky. We don't want you to come back in a couple of months with a thread asking where to find a new engine.

Les