I hate to add to this already long debate, however anyone who cares even somewhat about our environment and what environment your kids will live in.......should go rent the movie "An Inconvienent Truth".

Its about global warming (based on collected data) and I think it will change the way you feel about pollution.

 

Not quite about the Cat's but I figure it's close enough to ask here:

Do "crinkles" effect exhaust flow as much as they do intake? I found some DIY kits at a local Crappy tire (stainless, pretty cheap). Their 30, 45 bends are smooth, but the 90 bends have some rinkles on the compression side.

So is it worth it to go to a muffler shop and get mandrel bent smooth pipe?

 

most shops do crush bent seem to work fine for me

 

In regards to inconvenient truth, its a great movie, but catalytic converters don't help with carbon emissions, and that is what contributes to global warming .

Cats stop Nox, and prevent smog, which contributes to athsma and acid rain.

Did you know that all of the marble sculptures in Florence Italy have been replaced with fakes so the acid rain doesn't dissolve the stone?

If you go to the Hurst castle in California on the coast, you can see real marble sculptures outside because the air coming out from the pacific is clean enough not to dissolve the sculptures.

Grave stones are all made of granite now because the marble ones are being dissolved.

Random facts about using a catalytic converter, and these are some of the reasons it is a sensitive topic.

 

The whole reason for cats from what I understand is because of the inefficiency of the engine to burn all of the fuel that is injected (cleanly). So the cat is made to burn off the remaining fuel and whatever byproducts...
What my buddy and I would like to experiment with is a combination system of vapor fuel injection with high octane gasoline and H20 injection. The vapor fuel would burn cleaner and hotter, and if timed right the water injection would turn to steam instantly. Steam expands many times the rate of gasoline....thus creating a massive gain in power, and it would keep the engine cool enough (from the superhot explosion that the vapor fuel produces) so that the engine doesn't melt under heat pressure. But this is all in theory and has not been tested. But...if this system were to work it would basically eliminate the need for smog equipment and catalytic converters. In order to experiment with this, we'd need an engine we don't care if we hydrolock, and we'd have to rebuild that engine before we started to experiment so that it would withstand the steam expansion. Anybody got comments about such a crazy idea? Could it work? Call me an idiot if you wish.

Meanwhile...unless you're engine burns so clean that it doesn't put out any smog...keep the cats on. One tip...Jacobs electronics makes ignition systems which cause your fuel to burn a lot more efficiently.

 

Do some searching on WMI, its used to keep EGT's down on forced induction motors.... not 100% of what your talking about but similar....

A cat also changes the chemical makup of the exhaust to emit differnt gasses, the main reason its used. Actually if your putting too much fuel down the tailpipe you can ruin a cat, so it not really for unburnt fuel... just to reduce the NOX emmissions...

 

this is also why diesels dont need cats, they actually DO burn at over 2x the efficicency of their spark plug using cousins. Want an evironmentally friendly vehicle? Buy a DIESEL AFTER 2007...

A variant of the rotory engine could also be put into use sometime soon that actually uses photoignition, which is going to be even MORE efficient...

 

That's not true...

Have any docs to back that up?


Steam may expand with more force, but not with more volume.

 

AFIK all diesels come with cats now...