Engine 1991 Smog Pump Question

Ptstew

Member
Sep 21, 2017
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I have a 2002 FFR Cobra replica with a stock 1991 5.0L Mustang engine. One of the FFR supplied cats has broken and is not made anymore. The car is smog exempt so I plan on replacing the cats with j-pipes. These pipes do not have ports for smog pump air. If I don’t want to remove the pump can I either plug the hoses to the cats or leave them open to the atmosphere without adversely affecting the engine?
Thanks.
 
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Can you reroute the belt?



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You can't really block the hose (will build some pressure) and leaving it open will make noise that will be annoying
 
I have heard of X and H pipes. Was J pipe a typo, or what were you referring to?
In the Factory Five cobra setup, the stock exhaust manifolds are reversed, left to right and right to left, and the j-pipes go from the front discharging manifolds to the side pipes. The left and right exhausts are completely independent from each other so there is no X or H pipe.
 
I wondered if something unusual was going on. I have seen and read about engine swaps where reversed manifolds were used (like a 350 in a Chevette), but forgot what that pipe was called.
For sound quality and a bit of torque, is there room under a Factory Five Cobra for even a H crossover pipe?
 
I wondered if something unusual was going on. I have seen and read about engine swaps where reversed manifolds were used (like a 350 in a Chevette), but forgot what that pipe was called.
For sound quality and a bit of torque, is there room under a Factory Five Cobra for even a H crossover pipe?
The exhaust exits to the two side pipes right behind the front wheels. There is really no place to connect them. Thanks.