Phimosis

The resized pulley spins the s/c slower and makes less boost, which makes less horsepower. That setup up is safer, but it is not what they advertised to the public when they started accepting deposits on the kit.

The cash flow generated by the number of preordered kits was based on numbers that looked very impressive. If they later come back and say, "well the setup we were intially selling wasn't safe, so we are going to give you a kit that makes 50% less power for the same price," are you going to be satisfied?

I think most people would not.

I posed this question/statement to Stillen's sales team: A 108 whp increase is roughly 50% lower than what I was expecting based on Stillen's press release of +155 whp. Even with the pulley revision, I was expecting 140ish. But 108?

The response received from Stillen: "Please keep in mind a couple of key points: Your baseline dyno was performed on your car as it was received at our facility - with STILLEN Gen. 3 intakes. headers, high flows and a CBE on the car. Our press release compares a completely stock vehicle with a supercharged vehicle with a CBE. A 370Z with our Gen 3 intakes, headers, high flows and CBE will usually achieve an increase of 50 HP over baseline. So if you take 50 HP from your baseline of 312 your real baseline would be about 262 HP. Compare that to the 422 and you have an increase of 160 HP. Obviously some of that increase can be from the headers and high flow cats but those two parts would typically provide 20 HP on a supercharged vehicle (the supercharger replaces the Gen 3 intakes so it isn’t accurate to account for them on the baseline). Therefore the supercharger and CBE would be providing you with about a 140HP increase not 108 as you state."

I dunno. The dyno graph is post #976 on this thread (and reposted below). It says that the power made after modification with supercharger is 422.4 whp (at 68 degrees F ambient) and before modification it was making 315.5 whp (at 75 degreesF). Quick math with a calculator says that the increase in whp is 106.9 and the increase in torque is 51.4 lb/ft

The graph with the new pully is also quite different than what RCZ has resulted from post #930 in this thread. In his dyno graph, the car reaches 300 lb/ft torque at 3,800 rpm (at 99 degrees F). The graph in my post (#976) with the revised pulley shows 300 lb/ft of torque being reached at a higher 6,200 rpm.

I suspect the difference is because centrifugal superchargers do not make make much boost at low rpm. Think of a hair dryer with it's motor spinning at 3,600 rpm (60hz ac x 60 seconds = 3,600 rpm). It makes very little air pressure. But, spin it at 60,000 rpm and it would make real boost. So I am thinking the revised pulley is killing the midrange as their press release advertises 343 lb/ft of torque @ 5,800 rpm compared to the 306 lb/ft @ 7,200 rpm seen in post #976 with the new, revised pulley, as well as the car making no increase in power over baseline at 3,000 rpm or lower.

I have posed that question to Stillen and asked if something can be done to rectify the situation. I am awaiting response.