Yes.
Both actually. If you add more fuel, you need more O2. The PDR HX35 comes on about as fast as the stock and smaller HY35. I tried the PDR turbo before I upgraded the injectors and PE to a Comp and couldn't tell the difference as far a spool lag. As far as boost, yes, major improvement! Maybe the HX40 could put out more, but for the power I'm looking to get, the PDR HX35 is the catalyst to the kick in the pants more fueling adds. Piers is very easy to work with too. Give him a call. He is a wealth of information!