Strategies to keep cats from melting

[Torinate]

Here is what I’ve found for the passenger side cats.

FR3Z-5E212-B
Passenger stock cat GT

KR3Z-5E212-C
GT500 stock cat

Interesting g to see the part numbers are almost the same. I’m wondering if the difference with letters is model year specific.

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[shogun32]

Interesting g to see the part numbers are almost the same.

you can't read anything into part numbers. But given the chassis is the same and the pickup points for the exhaust ports are the same across the 5.x engine family, the liklihood of an easy swap is pretty good but by no means guarenteed.

 

[shogun32]

Stock Gen3 coyote: Commands .85 lambda at low rpm and .82 at high rpm. COT cannot command richer than .72 (combustion stability limit).

So if the EPA is perfectly happy with .75 or so on a SC motor, why would they care about guys slapping a SC on a Coyote and needing to likwise override the .82 to be more like .75? I mean they are trying to preserve the CAT functionality, no? The EPA should be giving LUND et. al. a medal.

Ford Performance has a slap-a-SC-on-your-Coyote kit which I'm sure uses .75'ish values.

 

[IamCDNJosh]

Interesting info Mike, I'm wondering what the values are on the FP/Roush cals?

 

[engineermike]

Looks like Roush Phases 1 and 2 are identical Lambda, starting at .85 at low rpm and .72 at high rpm. COT will not allow less than .70, so it looks like they're using the OEM-style FI strategy to stay out of COT.

 

[Dave2013M3]

I think as this progresses there will be more EPA friendly cats being made available. In Cali its not only EPA friendly but CARB friendly, meaning 50 states. Also, here in Cali we get a 7yr. 70k mile emissions warranty regardless what the manufacturer says. So if you are running a smog friendly blower with the factory warranty you should be covered. Or just prepare to pay every few years to replace these cats. You want to play you have to pay.

Not trying to piss on people who like to run blowers, but thats the beauty of factory blown vehicles. The cats are covered under warranty if they fail.

 

[shogun32]

Not trying to piss on people who like to run blowers, but thats the beauty of factory blown vehicles.

private party blower solutions cheat (if you prefer, cost-shift) by failing to provide an end-to-end system. Instead of tacking on another 2 grand for CATs that will keep up, they just suggest the buyer take a risk of the undersized factory equipment breaking, or run 'off-road' smog systems.

Most FI kits already require pumps, injectors, and other items, so adding CATs is no big leap.

 

[IamCDNJosh]

Looks like Roush Phases 1 and 2 are identical Lambda, starting at .85 at low rpm and .72 at high rpm. COT will not allow less than .70, so it looks like they're using the OEM-style FI strategy to stay out of COT.

Interesting, so for as much crap as the Roush/FP cal gets on this site it seems like they knew what they were doing (now the design itself of the gen 3 coyote blower is certainly up for debate).....

 

[engineermike]

Here is what I’ve found for the passenger side cats.

FR3Z-5E212-B
Passenger stock cat GT

KR3Z-5E212-C
GT500 stock cat

Interesting g to see the part numbers are almost the same. I’m wondering if the difference with letters is model year specific.

In the parts diagram the gt500 drivers side is separate from the header, which is different from the gt. The cost of this quickly jumped over $3000, and that’s assuming it bolts to the resonator.

 

[engineermike]

Interesting, so for as much crap as the Roush/FP cal gets on this site it seems like they knew what they were doing (now the design itself of the gen 3 coyote blower is certainly up for debate).....

I’ve said before that the roush cal, while lacking in a few areas, is a well-organized strategy with a lot in common with the predator. I’d guess that the same person either worked on or was consulted for both. It’s not oem quality, but has a lot of characteristics of a stock cal.

 

[Torinate]

Yea, the cats aren’t cheap. I didn’t look at the drivers side only passenger as I knew it was separate and not attached like the drivers side. Didn’t realize on GT500 the header and cat are separate on both side! Interesting. That would facilitate a much easier replacement for bad cats at the dealerships and alleviate the welding part of replacement.

$3k is stupid money!

 

[engineermike]

I smoked a drivers side cat and replaced it myself. This is the one integral with the manifold. The job was surprisingly easy.

If the predator PS cat won’t bolt directly to the gt header then it could approach $4000!

 

[shogun32]

$3k is stupid money!

cheaper than an EPA fine and court time... It's all relative. Unless the bends and pulse timing is all wrong bolting GT500 headers and cats to a Coyote would seem to be the easy answer. Then all you have to deal with are couplers at the resonator.

 

[Torinate]

cheaper than an EPA fine and court time... It's all relative. Unless the bends and pulse timing is all wrong bolting GT500 headers and cats to a Coyote would seem to be the easy answer. Then all you have to deal with are couplers at the resonator.

I’m not entirely convinced they’re not the same cats.

 

[engineermike]

I’m not entirely convinced they’re not the same cats.

Interesting thought since they’re both controlled to the same max temperature. My guess is the material is the same. I don’t know if the cell count, thickness, or diameter of the catalyst is different though.

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