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Does removing Catalytic Converter increase Power/Torque?

Discussion in 'The Garage' started by Firestarter7140, Apr 6, 2007.

  1. Firestarter7140

    Firestarter7140 Newbie

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    Hey i have a 91' K5 with a T.B.I. 350 an i was wonder does anyone knows if when you remove the catlyitic converter does it actually help because i've heard it increases power, i've heard it doesn't, and i've heard that it actually decrease power. Does any one know which is true and is it even worth it? (It doesn't have be legal)
     
  2. vortec

    vortec 1/2 ton status

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    there are a lot of variables to consider, such as other engine mods, but, assuming the cat is the most restrictive part of the exhaust (many monolithics are not as bad as the old pellet type), removing it will most likely net hi-rpm hp gains because of improved flow and higher air velocity. this is often at the expense of low-end torque, because exhaust scavenging is hurt. some backpressure is needed to reflect the lower-pressure pulses traveling through the pipes and manifold to aid in removal of exhaust gasses from the chambers. pipe bends, surface texture, temperature, etc. create a very dynamic environment in the exhaust system. crunching some numbers with pvnrt (PV=nRT) can explain and quantify some of the mess.

    my k5's old cat was gutted, and when i replaced it for inspection, my low-end grunt improved just a little. on my other truck, when i got higher-flow exhaust, my top speed improved significantly, but my off-the-line suffered a tad. that has been remedied, though.
     
  3. Firestarter7140

    Firestarter7140 Newbie

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    its pretty stock but has a power chip, i doubt this matters but it also has a 2 in. lift an 33in tires which i am looking to improve on when i have more money. i will also probally do any cheap mods i can to improve the engine
     
  4. sled_dog

    sled_dog 1 ton status

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    a 91 K5 would have the old pellet style cat. Those things are pretty crappy on flow. I am not a big pusher of dumping Cats myself. A high flow unit can be bought cheap on Ebay, still function and add very little restriction to the exhaust.
     
  5. vortec

    vortec 1/2 ton status

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    cats are getting as cheap as mufflers, in come cases. my exhaust guy charged me $75 installed (i don't have a welder) for my magnaflow cat. my dynomax muffler on the pickup cost more than that before installation. i like the way my k5 drives now better than with the gutted stock cat. plus, it's a little quieter and sounds less "farty". still sets off car alarms, though.
     
  6. Firestarter7140

    Firestarter7140 Newbie

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    would removing the muffler do any thing for me?
     
  7. sled_dog

    sled_dog 1 ton status

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    make it really loud. Mufflers in stock applications aren't really that restricting.
     
  8. vortec

    vortec 1/2 ton status

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    x2:waytogo:
     

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