Long tubes w/ Kooks green cats - no tune?

[Mike2019SCrew]

Title, basically. Livernois rep is telling me I don't need a tune revision on my 22 Whipple 5.0 when installing 2m headers with Kooks cats welded in. I'd just like some confirmation...

EDIT: I can't spell.

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[dolsen]

Really the only thing the tune does is change the parameters of the oxygen sensors. Since the cats are further downstream, the exhaust, and therefore the cats, cools off more and doesn’t burn off all of the gas and emissions quite as well (there’s more to it than that but I cannot remember all of the details) and it’ll throw an O2 code. It’s possible their initial tune desensitized the sensors enough to not throw a code

 

[Mike2019SCrew]

Gotcha. I was under the impression that a tune revision was helpful if not necessary due to the increased flow of the long tubes - not simply to get rid of the CEL (which most tuners won't do anyway).
If a revision isn't necessary, that certainly makes my life easier!

 

[dolsen]

Gotcha. I was under the impression that a tune revision was helpful if not necessary due to the increased flow of the long tubes - not simply to get rid of the CEL (which most tuners won't do anyway).
If a revision isn't necessary, that certainly makes my life easier!

I’m not well versed in tuning specifically, but I believe the tuning has more to do with just shutting off CEL’s by increasing the tolerance allowed with the oxygen sensors. The real increase comes from the increased efficiency of expelling exhaust. Most long tubes will increase exhaust scavenging which I think is more of a Venturi effect causing the exhaust gases to escape more quickly.

I have an intermediate level of knowledge with exhaust and exhaust gases, so I could be wrong, I’m simply explaining how I understand it

 

[Davidwnuc]

i can not confirm either side, but
i think you would benefit from a dyno tune with the addition of the headers. you will be changing how much air is getting moved. but NEED, probably not.
you could search around for previous gen examples and see what has been done?
i bet you find arguments for both sides.
let us know how it goes. i have a roush supercharged truck and would be interested in the results.

 

[TheGoatman]

This guy did a good job going through it

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