catillatic converters

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It depends on what type of cats you're talking about. If you're referring to the stock set-up of four cats on the H-pipe, this is more restrictive than the after-market set up of one cat per pipe offered by all the exhuast companies. The gain with no cats is negligible according to many dyno sheets I've seen. Call me a tree hugger, but I would much rather pump cleaner air into the atmosphere than worry over a couple of horsies.
 
It is not nearly as much as the first sets of cats that came out back in the day. As long as they function properly on a mostly stock stang, they are not hurting you much. A set of equal lengths and some muffs would get you a few ponies.

To be technical it is a federal offense to tamper with any functioning emissions device with the intention of defeating it. Not that I think you will spend time in a federal prison.
 
if your tryin to get the look of cats, you could always weld on heat shields. I toyed with the idea of doing that, but i think in the end i'm going to have some hi-flow cats clamped or welded in. From what i've seen, there isn't much performance lost and its nice to have the piece of mind that you aren't breaking any laws.
 
These are all valid points in mentioning that my car is stock. however, I just recently bought a 331 engine, which my avatar suggest, and I am putting it in soon. After I put everything in, including a vortech supercharger and a tremec TKO6 transmission, I am going to work on exhaust and my friend urged me not to put cats on because I would loose significant horsepower.
 
According to Ford:

"It is illegal to remove either the converters or there substrate from street-driven vehicles. Converters can be removed only when legal replacements are being installed or when the vehicle is operated only off-road. Removing the specially coated ceramic monolithic honycomb material that fills the insides of the OE catalytic converyters or the converters themselves is not recommended, because the reduction in back pressure confuses the computer and hurts the engine's low end torque output. Although some sources have claimed an increase of 10 horsepower when the converters are removed from the system (for off-highway-only operation), the V-8 Mustang's production converters are recognized as being minimally restrictive."

Most of the time you will see higher trap speeds at the track but virtually the same times.
 
willys1 said:
and theres no cheap materials inside to melt and clog anymore
last time i checked, cats used precious metals, not cheap stuff. :)

i agree that some of the newer cats dont use the traditional honeycomb design - dont know much about them though.
 
Without the cats you get poisoned, with them you just suffocate. What fun is that? I like the smell of burned gas, makes the late model cars seem more 60's muscle car like.

I read somewhere that the stock cats take up 10hp on a 300RWHP car. So if your going to push over 400RWHP and are going to drive on the street, get some high flow cats.

I think most people change to high flow cats for a different exhaust sound. High flows and O/R pipes will usually make the exhaust louder.
 
Following the link posted, cats are bad for global warming because of the high N2O emmisions according to the EPA! Now if we can come up with some sort of nanofilter that can gather the N2O, store them and use them as a constant N2O feed system to the engine :D
 
Everything fun is illegal. There's a law against everything immaginable. Go do what makes you feel good about the car. Offroad exhaust sounds many times ballzier than any catted setup and gives you that deep bass roar that the cats muffle and tone down. Weld some heatshields to your OR exhaust to satisfy the local police or get a mac prochamber that looks like a big catalytic converter (even has an airtube hookup for some inexplicable reason) then make friends with the local inspection station. I've had some dealership inspector bust my *ss about a fully catted, FI, all stock car. Next year I passed with a carbed car missing the charcoal cannister and EGR at a station where I have a lot of work done a month before. Nuff said.
 
HISSIN50 said:
last time i checked, cats used precious metals, not cheap stuff. :)

i agree that some of the newer cats dont use the traditional honeycomb design - dont know much about them though.
The regular cats that Bassani uses are made overseas and use cheap material inside the cats.Thats what melts and clogs.