Clearly the factory size converter with the outdated ceramic innards will not work with a large turbo. It is simply too small and restrictive. This has been proven – ATT will not spool with a factory kitty. Emissions attempting to do this cause vehicles in other testing bays to ALSO fail from the smoke cloud.
This leaves me with a problem to solve as the engine is already built with the ATT and emissions are due. The OEM kitty ate too much antifreeze and oil and died from this contamination. Roto rooter did not help as the 3” banks exhaust had to go away when the 4” exhaust arrived. With the rear heater hoses there isn’t a good place to mount a gutless 3” kitty. Not sure that factory is as far back as mine is/was.
So in the junkyard of mine I came across a 4” kitty that fell off a 2008 Duramax. Kitty is larger in diameter but has more or less 4” in and out. The flanges were replaced with welds so the falling off problem with our rough roads will not happen again.
This 2008 design has spun metal vs. the ceramic substrate design. This translates into less restriction as the metal is thinner than the thick walled ceramic design. It can also take higher temperatures without melting. In fact raw diesel vapor is fed to it to burn the soot out of the DPF. It also means more room between the elements for soot to blow through rather than plug it up.
So we have a modern 4” ‘spun metal’ kitty on a 4” exhaust. A special tune was used and emissions passed. (Snap test.) :thumbsup:
Here is the good news! The regular tune runs just fine with this 4” kitty in place. So an A Team Turbo is running emissions legal with no effect on performance as far as I can tell. Of course I am limited by my precups and am only using 17PSI of boost max.
I suggest that the 4” performance converter that is spun metal would also work well. Duramax exhaust parts should be common as some owners regularly have trouble with them falling off. So testing one of these 4” kittys with 6.5 turbo, diamond, precups at higher boost would be in order. Even limited to 17 PSI of boost is a victory for a better turbo!
Some places like CA do not allow used converters to be installed and have to have an EO number for an new aftermarket converter used. Good luck getting the Magnaflow 4” spun metal converter through CARB or being in compliance if it is. I’ve not looked it up. :skep:
This leaves me with a problem to solve as the engine is already built with the ATT and emissions are due. The OEM kitty ate too much antifreeze and oil and died from this contamination. Roto rooter did not help as the 3” banks exhaust had to go away when the 4” exhaust arrived. With the rear heater hoses there isn’t a good place to mount a gutless 3” kitty. Not sure that factory is as far back as mine is/was.
So in the junkyard of mine I came across a 4” kitty that fell off a 2008 Duramax. Kitty is larger in diameter but has more or less 4” in and out. The flanges were replaced with welds so the falling off problem with our rough roads will not happen again.
This 2008 design has spun metal vs. the ceramic substrate design. This translates into less restriction as the metal is thinner than the thick walled ceramic design. It can also take higher temperatures without melting. In fact raw diesel vapor is fed to it to burn the soot out of the DPF. It also means more room between the elements for soot to blow through rather than plug it up.
So we have a modern 4” ‘spun metal’ kitty on a 4” exhaust. A special tune was used and emissions passed. (Snap test.) :thumbsup:
Here is the good news! The regular tune runs just fine with this 4” kitty in place. So an A Team Turbo is running emissions legal with no effect on performance as far as I can tell. Of course I am limited by my precups and am only using 17PSI of boost max.
I suggest that the 4” performance converter that is spun metal would also work well. Duramax exhaust parts should be common as some owners regularly have trouble with them falling off. So testing one of these 4” kittys with 6.5 turbo, diamond, precups at higher boost would be in order. Even limited to 17 PSI of boost is a victory for a better turbo!
Some places like CA do not allow used converters to be installed and have to have an EO number for an new aftermarket converter used. Good luck getting the Magnaflow 4” spun metal converter through CARB or being in compliance if it is. I’ve not looked it up. :skep: