Exhaust Education

[SoulJacker]

Hello all, would anyone care to take the time to teach me or steer me in the right direction on learning the vocabulary of the exhaust system of our stingers and the aftermarket applications? So the stock exhaust system has the parts labeled on every kia parts website. What confuses me is when I start seeing the aftermarket parts like primary downpipe, secondary downpipe, midpipe, HFC downpipe, primary cats, secondary cats, etc lol. I'm confused because I don't see that terminology on the stock diagram. For example, I understand HFC is the high flow cat but is that also considered the primary cat. Appreciate all that took the time to read this and answer.

 

[AusStinger]

Here's the terminology I'm familiar with.

The first pipes exiting the turbos are called the primaries and contain the primary ( metal ) cat converters.

Next comes the secondaries ( or down pipes ) which contain the second pair of cats ( ceramic ).

Next are the mid pipes which contain the resonators.

And last are the rear mufflers ( AKA axle back ).

 

[G70LEbyAdoom]

Here's the terminology I'm familiar with.

The first pipes exiting the turbos are called the primaries and contain the primary ( metal ) cat converters.

Next comes the secondaries ( or down pipes ) which contain the second pair of cats ( ceramic ).

Next are the mid pipes which contain the resonators.

And last are the rear mufflers ( AKA axle back ).

You pretty much nailed it. That's about it exhaust wise. The 22+ have a valve somewhere near the exit to make the sound and flow rate variable, but that's the only part not mentioned. (Side note, I Believe the Australian stingers ALWAYS had the exhaust valve in it, from 18+)

 

[Redleg94]

You pretty much nailed it. That's about it exhaust wise. The 22+ have a valve somewhere near the exit to make the sound and flow rate variable, but that's the only part not mentioned. (Side note, I Believe the Australian stingers ALWAYS had the exhaust valve in it, from 18+)

US Spec 22+ 3.3 Stingers have a valve in the outer exhaust tail pipes (iow after the mufflers) on both sides that open when the car is in sport mode.

 

[G70LEbyAdoom]

US Spec 22+ 3.3 Stingers have a valve in the outer exhaust tail pipes (iow after the mufflers) on both sides that open when the car is in sport mode.

Yes, Those are the ones.

 

[SoulJacker]

Here's the terminology I'm familiar with.

The first pipes exiting the turbos are called the primaries and contain the primary ( metal ) cat converters.

Next comes the secondaries ( or down pipes ) which contain the second pair of cats ( ceramic ).

Next are the mid pipes which contain the resonators.

And last are the rear mufflers ( AKA axle back ).

Thank you! So the high flow cat is the primary downpipe?

 

[G70LEbyAdoom]

Thank you! So the high flow cat is the primary downpipe?

Correct

 

[SoulJacker]

Really appreciate everyone's input in this thread. I read somewhere it's not advisable to change the primary downpipe maybe secondary downpipe due to the possibility of a blown head gasket is this true?

 

[G70LEbyAdoom]

Really appreciate everyone's input in this thread. I read somewhere it's not advisable to change the primary downpipe maybe secondary downpipe due to the possibility of a blown head gasket is this true?

No, Primary downpipes will not blow the head gasket. An extremely aggressive tune will. You may have some oil blow by with catless downpipes, but not HFC's

 

[SoulJacker]

Thank you! Now the full exhaust systems available for our cars only go back to the secondary pipes? For example, the borla S type system?

 

[G70LEbyAdoom]

Thank you! Now the full exhaust systems available for our cars only go back to the secondary pipes? For example, the borla S type system?

Most of them are this way, yes, however you can also get system from companies such as IMR America, which also make their own in house Primaries and secondaries.

 

[Daniel @ K8 Stinger Store]

The order from the turbos is going to:
primary -> secondary (aka mid pipes) -> catback.

Feel free to send me a message if you need some help making a decision on a part to go with, I would be glad to help out.

 

[SoulJacker]

Thank you all for the input, I really mean it. Once I got my stinger back from the delearship I'm looking to put at least one mod in to start lol.

 

[GennyGuy]

No, Primary downpipes will not blow the head gasket. An extremely aggressive tune will. You may have some oil blow by with catless downpipes, but not HFC's

You can still have blow by with HFCs. They are not all the same cell count. A higher cell count should equal less blow by. But you can have 200 cell HFC or an 800 cell HFC (these are random examples, actual cell counts may vary).

 

[G70LEbyAdoom]

You can still have blow by with HFCs. They are not all the same cell count. A higher cell count should equal less blow by. But you can have 200 cell HFC or an 800 cell HFC (these are random examples, actual cell counts may vary).

Good point.

 

[SoulJacker]

You can still have blow by with HFCs. They are not all the same cell count. A higher cell count should equal less blow by. But you can have 200 cell HFC or an 800 cell HFC (these are random examples, actual cell counts may vary).

What do you mean by cell counts?

 

[G70LEbyAdoom]

What do you mean by cell counts?

"The number of cells in a catalytic converter always refers to the number of cells per square inch. For example, a 100-cell cat has 100 cells per square inch, while a 200-cell cat has 200 per square inch. While a standard cat often contains 400 or more cells, 100 to 200 cells are more generally used in motorsport."

 

[GennyGuy]

"The number of cells in a catalytic converter always refers to the number of cells per square inch. For example, a 100-cell cat has 100 cells per square inch, while a 200-cell cat has 200 per square inch. While a standard cat often contains 400 or more cells, 100 to 200 cells are more generally used in motorsport."

Think of the cells like mesh or chainmail armor. The more cells or mesh you have, the harder it is for something to get through. In this case what's being prevented from flowing through is exhaust gasses, etc. Most catless downpipes will have 0 cells, so all of the gases pass through. As you increase the cell count, less passes through. So less oil blow by as well.

 

[SoulJacker]

Very interesting, I'm learning so much since I've owned this car lol. So a higher cell count is better to prevent blow by? Blow by is the fuel and oil by products from combustion aka carbon build up? A lower cell count means meaner exhaust sound?

 

[GennyGuy]

Very interesting, I'm learning so much since I've owned this car lol. So a higher cell count is better to prevent blow by? Blow by is the fuel and oil by products from combustion aka carbon build up? A lower cell count means meaner exhaust sound?

"Better" is going to be subjective to your goals.