Getting FLP put on next weekend and wanted to know if Borla flows alright with the plate totaly blocked off. I use to have MAC with no cat and the think was loud as hell. Back fired all the time. Question is does borla flow worse then any other cat back, when the plate is closed. I know there are two pipes coming off the bolra to the driver side exhaust tip, instead of normal mufflers that have two pipes coming off the muffler to each side. Does this mean it would flow the same or close?

 

I have a Borla with the same MAC setup and mine sounds just fine. Doesn't hardly pop at all. Anyway back to your question. I don't think that there is that much difference between it being open and blocked off. I ran mine fully open and fully closed at the track this summer and seen no difference at all. Same trap speed and same ET. So the Borla still flows really good even when it's blocked off. I don't think that any other exhaust is going to out flow it enough to make a difference. Like I said above I ran the same with open headers and with it blocked off. So it still flows pretty good even when blocked off. The only change I noticed was sound. Hope this helps.

 

TTT

 

I dyno'd my car with the Borla open and closed and put out about 3 more HP and TQ with the Borla completely capped. I also have FLP's and I was using the OR pipes. #'s in the sig.