Loss of boost??

[Ryan03termi]

Im new to svtp and this would be be my first post on here. Well i just did my first mods to my cobra a couple weeks ago. I installed a bassani off road x pipe and a borla catback. I seemed to notice when i did a few pulls that my boost seemed to be dropping off. Why is that? Im currently on the stock pulley also.

 

[JuStAkId]

Im new to svtp and this would be be my first post on here. Well i just did my first mods to my cobra a couple weeks ago. I installed a bassani off road x pipe and a borla catback. I seemed to notice when i did a few pulls that my boost seemed to be dropping off. Why is that? Im currently on the stock pulley also.

Lack of back pressure