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For anyone who has been following my upgrade of a '76 'Sud berlina to a 16V powertrain (keeping the stock Bosch fuel injection), I am now in the process of sorting out the exhaust. I am keeping the inboard front disc brakes and would like to install the best possible system. Does anyone have any suggestions? Here are a few questions:

• Is the crossover exhaust the best performance idea? How much HP and Torque does it add? I thought that the original Ansa system was supposed to be a major improvement. Does the crossover make the car sound better or worse? Technically, it should result in better performance due to superior pulsing of the cylinder output.

• What pipe diameter is best for this system?

• My engine came from a German car (engine I.D. #: AR307470002855). I'm not sure if it had a catalytic converter on it as standard. Does anyone know? And do I need to keep the cat due to the Bosch F.I., meaning is the computer looking for an 02 sensor and will not run correctly if I eliminate the cat?

• If a cat is required, I will probably use the super free-flow 8100 series from www.randomtechnology.com What diameter in/out would work best with the rest of the system?

• Is anyone familiar with the original Ansa system? The expert at the U.S. Ansa warehouse told me that he can match a resonator (if needed, or replaced by the cat?) and muffler to a new one in their catalog if I can give him the dimensions from the original system.
 

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  • From what I've heard the crossover exhaust makes the exhaust note a little busier.
  • For a road going 16v, I think no bigger then 2 1/4"
  • There is no difference in the FI on cat, and non-cat cars. The only difference is the cat. The o2 sensor goes before the catalytic converter so it doesn't matter..
As for the last 2 points I have no idea.

lenus.
 

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Has anybody got any advice about exhaust diamiter for a 1.7 16V engine, would 2 1/4" pipe into a 2.5" out twin tip muffler be to free flowing, or would the engine be able to maintain correct back pressure?
 

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Cross exhaust gives better torqe because it compines the the back pressure of 2 different cylinders at every stroke. Thats why the sound is a little bit different...
 
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