Hi Flow CAT

[smoka_9]

If any one can give me good inf on a high flow CAT it would be appreciated. I am looking to purchase one to compliment the 2.25" exhaust piping and Hotshot Header.

[smoka_9]

I have done some shopping around and have narrowed it down to two choice Carsound(32.95 @ ebay) or Xtreme Flow(99.99). Has anyone heard anything about either of these? Any feedback would be appreciated.

[miamisl2]

or you could hollow out your stock cat with a broomstick and put on an o2 simulator if you have an obd2 car. much cheaper and better. though illegal.

[ratpak07]

if you hollow out your cat , you lose torque(valuable foor take off) the back pressure gives you more torque, i dont kow why, it just does

[miamisl2]

hollowing out the catalytic converter is going to give you more flow and power. backpressure gives you more low rpm power (usually made by bends), skinnier exhaust tubing will also give you better low rpm power because you're rasining the velocity of the exhaust gases exiting your engine, but at high rpms the exhaust gases wont be able to get out as quickly becuase there is much more exhaust and the piping just isnt big enough, so you're going to lose power there... with bigger piping and no bends, youre gonna gain high rpm power but loose low rpm power because now you can scavenge much more exhaust gases by volume, but the velocity is decreased.

dont make the assumption that low rpm power is torque. torque is how you rate a motor in ft lbs.... horsepower is just a rating that is come up with using a forumla for torque at a certain rpm. you could loose a couple ft lbs at 2k rpms and gain 5 at 4k, every motor has its peak, but it'd be wrong to measure torque using only a certain part of the powerband.

i have no catalytic converter, no resonator. just a straight 2 1/4" pipe from the exhaust manifold to a moroso spiralflow muffler under the car with no bends, except for a turndown at the tip. i also have a cc collector insert inside the piping where the cat used to be to quiet it down, its kind of like a tube with two circles around it and a bunch of holes in it. anyway, i used to have that setup with one bend and no morosso muffler, car sucked off the line but ripped from 3500 rpm and shifted damn hard, but i couldnt chirp the tires from a powerbrake for sh**, proving my low rpm power was suffering. after putting on the muffler, and getting rid of the bend (you'd think i have no backpressure), getting smaller diameter tires, and turning down the fuel pressure a bit, the car takes off very nicely off the line and still shifts almost as hard (meaning it still feels like my high rpm power is almost as good) as when i didnt have the muffler at all, and the car will peel out easily.