Cats or no Cats
Race Director
Joined: Oct 2004
Posts: 10,089
Likes: 14
They aren't complaining about SO2, which I agree is really the objectionable smell, and is only present on catted cars. What they're complaining about is the aroma of partially burned hydrocarbons. I don't find that smell objectionable, and neither do most gearheads, but some people do.
Team Owner
Joined: Aug 2003
Posts: 38,314
Likes: 35
....
Either way you slice it, the so-called high flow cats are a bad choice. On the one hand, they don't do a good job of reducing the already relatively benign HCs because their efficiency is low, and on the other hand they do nothing to reduce NOx (none of the so-called high flow cats are 3 way). And on the third hand, they really don't help performance much if at all either. Just a waste of good money.
Either run with the OEM cats, or do without. Both are better choices than the so-called high flow cats. In my opinion, running with the OEM cats, even relocated if necessary, is the best choice. They have negligible effect on power output, but they do a good job of reducing NOx, the real villian of auto pollution. They keep you legal too, if you don't relocate them. If you do relocate them, they still do their job of reducing NOx, but won't light off as quickly and will allow increases in the relatively benign HC emissions during warm up, but still less than the other alternatives of no cats or using the so-called high flow cats.
Either way you slice it, the so-called high flow cats are a bad choice. On the one hand, they don't do a good job of reducing the already relatively benign HCs because their efficiency is low, and on the other hand they do nothing to reduce NOx (none of the so-called high flow cats are 3 way). And on the third hand, they really don't help performance much if at all either. Just a waste of good money.
Either run with the OEM cats, or do without. Both are better choices than the so-called high flow cats. In my opinion, running with the OEM cats, even relocated if necessary, is the best choice. They have negligible effect on power output, but they do a good job of reducing NOx, the real villian of auto pollution. They keep you legal too, if you don't relocate them. If you do relocate them, they still do their job of reducing NOx, but won't light off as quickly and will allow increases in the relatively benign HC emissions during warm up, but still less than the other alternatives of no cats or using the so-called high flow cats.
It would also be very dificult, if not impossible for him to use his original catalytic converters in series with long tube headers.
He'd have to cut them off and weld a flange to them, so that they would mate to the header flange. And then to an X pipe. And then they'd have to tuck underneath the car somewhere in order to provide adequate ground clearance.
Burning Brakes
Joined: Mar 2003
Posts: 1,030
Likes: 0
From: Pittsburgh PA
They aren't complaining about SO2, which I agree is really the objectionable smell, and is only present on catted cars. What they're complaining about is the aroma of partially burned hydrocarbons. I don't find that smell objectionable, and neither do most gearheads, but some people do.
You know, it does smell richer. However, the color at the exhaust pipe is perfect, the LTFTs are fine and WOT AFR is 13.1. Maybe the nose is more sensitive than numbers.
