I had a boost lag issue on my SL 55 and i ordered a Johnson CM30 pump and had my shop install it. After install i realize I still had the same problem so I lifted the car and looked to see if everything was installed right. In the picture there are 2 pumps, one on right is the new Johnson CM30 pump but I noticed there's another pump on the left, a slightly bigger pump, can anyone tell me what the other pump is for? Does the bigger pump have anything to do with my boost lag?