alfadriver said:Knurled. said:In reply to Rufledt :
"Modern cats" are actually a lot smaller than the 70s and 80s converters. One funny side effect of having faster computers, and wideband oxygen sensors, is there is no longer a big swing across stoich. The computers are fast enough and the sensors accurate enough that they can control to precisely stoich, cylinder by cylinder with only one sensor in some cases. What this means is the converter no longer has to be an enormous brick to handle being loaded up with hydrocarbons and CO2, and then flush it all out with oxygen when it swings lean, and so on.
If you want to update the emissions controls on an older engine, start with the engine management.
Yea, big yea. Add an accepted universal catalyst with a WB controlled MS to your classic car, and you will be doing a LOT of good. I'd add making sure the PCV system is working and sealed, and that the fuel system has some kid of vapor control that the engine gets to burn. None of that is overly complex, but it will be SO much more effective.
Bonus is that you will enjoy the car better, since you won't be fighting a CO headache and your clothing won't smell like unburt gas.
Most people see my engine bay on my integra and wonder why I have all the emissions components still on it and working, as much as I enjoy a fun to drive car that makes cool noises, going the extra effort to have a cat, functioning EVAP system and the creature comforts make the experience even better for me.
It seems explaining to them, "I hate the associated smells and makes me nauseous" gets people understanding why it isn't a bad thing to keep those components in at the expense of total peak power.