I have a 02 with the 4.7. putting headers on the new motor. I have read the stock y pipe is restrictive. What exactly makes it that way? the size? the bends? taking it to exhaust shop but would really like to be able to tell him what i want.

 

 

Someone has a picture of the factory Y and the Magnaflow Y and the factory one looks crimped with a giant pair of pliers compared to the Maggy

 

Any Y pipe IMO is somewhat restrictive. Just think about it, you are channeling the airflow from two pipes into one. But as said above 2x, the OEM y pipe is kinda crushed together to fit into one pipe

 

You DON'T want this:

Stock



You WANT this:

Maggy



My four year old niece could tell you which one flows better...

 

Could you ask youre niece what magnaflow muffler to pair with this?

 

^^^ LOL

For whats its worth, I vote for Magnaflows over Flowmasters.