Optimal CAI and Cat-Back Combination for Power

[Squatting Dog]

Yeah, because it would be a hai (hot air intake) instead of a cai (cold air intake)

 

[pirate air]

I didn't see it. My baaaad.. Personally, this is the way I would go.. Package deal, cai and tuner.. That way if there is anything wrong, only one person/company to deal with.

here ya go! you can get the lid for it too.
http://www.fordraptorforum.com/f77/5-star-intake-power-core-100-000-mile-filter-3322/

 

[Deinonychus]

If you got an optimal tune for a CAI and later added a cat-back, wouldn't you need to upgrade your tune?
If that's not the case, it would seem logical to assume that an addition of a cat-back is a zero performance investment. All bark, no bite.

Can we state that an aftermarket cat-back is a performance enhancement? ... or not?

 

[SilverBolt]

If you got an optimal tune for a CAI and later added a cat-back, wouldn't you need to upgrade your tune?
If that's not the case, it would seem logical to assume that an addition of a cat-back is a zero performance investment. All bark, no bite.

Can we state that an aftermarket cat-back is a performance enhancement? ... or not?

A catback is zero performance increase. Sound improvement only. Long tubes and high flow cats will show nice gains.

 

[Hockster]

If you got an optimal tune for a CAI and later added a cat-back, wouldn't you need to upgrade your tune?
If that's not the case, it would seem logical to assume that an addition of a cat-back is a zero performance investment. All bark, no bite.

Can we state that an aftermarket cat-back is a performance enhancement? ... or not?

I cant say its a total no HP gain since they do reduce underhood temps some. I really dont think you would need to change your tune for a catback install. Now add headers and a catback and hell yes you will need to change the tune...

 

[Deinonychus]

A catback is zero performance increase. Sound improvement only. Long tubes and high flow cats will show nice gains.

Do you have any empirical evidence?

 

[SilverBolt]

Do you have any empirical evidence?

About 30 years worth.

 

[Deinonychus]

About 30 years worth.

In those 30 years did you ever have a before and after cat-back only dyno run?

Sorry, but I have a strong inclination toward empirical data.

 

[SilverBolt]

In those 30 years did you ever have a before and after cat-back only dyno run?

Sorry, but I have a strong inclination toward empirical data.

Absolutely. In modern cars/trucks the restriction in the exhaust is at the manifolds and in the cats. The catbacks actually flow quite well. If you are relying on a chassis dyno for your "empirical data" your results will be anything but empirical. An engine dyno is the only way to acurately measure and verify gains.

When attempting to see small gains in power a chassis dyno has far too many varibles to be accurate. Air temp, humidity, tire pressure, tire slippage, gear selection, etc.

Try this little test the next time you are on a dyno. Complete your baseline run and the shut the vehicle off. Remove the negative battery cable and discharge any residual voltage. Reconnect the negative cable and do another dyno run.

 

[Deinonychus]

Absolutely. In modern cars/trucks the restriction in the exhaust is at the manifolds and in the cats. The catbacks actually flow quite well. If you are relying on a chassis dyno for your "empirical data" your results will be anything but empirical. An engine dyno is the only way to acurately measure and verify gains.

When attempting to see small gains in power a chassis dyno has far too many varibles to be accurate. Air temp, humidity, tire pressure, tire slippage, gear selection, etc.

Try this little test the next time you are on a dyno. Complete your baseline run and the shut the vehicle off. Remove the negative battery cable and discharge any residual voltage. Reconnect the negative cable and do another dyno run.

The trouble with removing the battery cable (at least for computer run motors/transmission) is that you erase all the computer adaptives. Now the car would be trying to re-learn the tune.

It might be that the fundamental issue of erasing the adaptives would be "closed loop" operation, but I would be concerned that some open loop operation could be affected too. (my only dyno tune experience is with a 2005 Mopar with a larger motor that was further stroked and more cam, and my computer doesn't like it very much. It takes about 300 miles for the computer to allow a reasonable idle after a new tune or a battery disconnect.)

If I understand your position, you believe that the stock exhaust resistance is primarily in the exhaust manifold and the cats. Assuming that is correct, if you added headers and high flow cats, would the stock cat-back present itself as an opportunity to make better flowing (i.e., getting an aftermarket cat-back)