DEC Catalytic Converter Users
06-09-2012, 07:11 PM
#16
Rennlist Member
I talked to the DEC guys on the phone several years ago. My recollection is that they concurred DEC aftermarkets have less life than the stock cats on the 951, which is pretty hard on cat life.
06-09-2012, 09:59 PM
#17
Addict
Rennlist Member
Rennlist Member
I don't know, but would suspect in many cases the difference is simply the certification and labelling procees (and associated cost).
This dec aftermarket has a little honeycomb stuffed into the dump tube (no bulging canister like the factory) so clearly less catalyst material than stock -- although maybe equally effective compared to less efficient 80's technology? The main cat is about the size of the factory cat, but I wonder how much of the exhaust actually passes through that at low load...?
This dec aftermarket has a little honeycomb stuffed into the dump tube (no bulging canister like the factory) so clearly less catalyst material than stock -- although maybe equally effective compared to less efficient 80's technology? The main cat is about the size of the factory cat, but I wonder how much of the exhaust actually passes through that at low load...?
Here is a slide presentation on the cat situation: http://www.arb.ca.gov/msprog/aftermktcat/amcatpres.pdf
And here is a list of exempted converters: http://www.arb.ca.gov/msprog/aftermk...xemptcat09.pdf
I think our cars fall in the “1995 & older” “PC-1 pre OBD II PC” category (PC = passenger car).
The waste gate (WG) pipe, where the small honeycomb (mini-cat) sits, is only flowing air when the WG is open and that should only happen near max boost (for each rpm). Even then, it will take many seconds to heat up the pipe and the mini-cat to make it function.
In post #11 you were saying: “Since a good portion of the exhaust goes through the WG during the test ...”
Why that? I don’t think there is any flow in that pipe during CA smog testing (WG and its control healthy).
Laust
06-24-2012, 03:03 AM
#18
Rennlist Member
Thread Starter
I went in on CARB’s website http://www.arb.ca.gov/msprog/aftermk...ftermktcat.htm and as far as I read it, you are right. They “just” want certified tests to exempt them from exclusion from the California market and then they issue an Executive Order like this: http://arb.ca.gov/msprog/aftermkt/de...o/D-280-72.pdf
Here is a slide presentation on the cat situation: http://www.arb.ca.gov/msprog/aftermktcat/amcatpres.pdf
And here is a list of exempted converters: http://www.arb.ca.gov/msprog/aftermk...xemptcat09.pdf
I think our cars fall in the “1995 & older” “PC-1 pre OBD II PC” category (PC = passenger car).
The waste gate (WG) pipe, where the small honeycomb (mini-cat) sits, is only flowing air when the WG is open and that should only happen near max boost (for each rpm). Even then, it will take many seconds to heat up the pipe and the mini-cat to make it function.
In post #11 you were saying: “Since a good portion of the exhaust goes through the WG during the test ...”
Why that? I don’t think there is any flow in that pipe during CA smog testing (WG and its control healthy).
Laust
Here is a slide presentation on the cat situation: http://www.arb.ca.gov/msprog/aftermktcat/amcatpres.pdf
And here is a list of exempted converters: http://www.arb.ca.gov/msprog/aftermk...xemptcat09.pdf
I think our cars fall in the “1995 & older” “PC-1 pre OBD II PC” category (PC = passenger car).
The waste gate (WG) pipe, where the small honeycomb (mini-cat) sits, is only flowing air when the WG is open and that should only happen near max boost (for each rpm). Even then, it will take many seconds to heat up the pipe and the mini-cat to make it function.
In post #11 you were saying: “Since a good portion of the exhaust goes through the WG during the test ...”
Why that? I don’t think there is any flow in that pipe during CA smog testing (WG and its control healthy).
Laust
