2004 - 2008 F-150

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  #16  
Old 03-01-2007, 02:58 PM
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Originally Posted by Tbird69
The stock manifolds are a compromise between power, performance and economy. The result is this design makes them very inefficient at moving the exhaust out of the motor. Installing headers improves the exhaust flow by giving each cylinder it's own pipe. A properly tuned header will actually pull the burnt gases out of the cylinder. The pipes come together at the collector which then connects to the exhaust pipe. All this helps the engine to run more efficiently and build more power. An air intake system with a proper header and exhaust can improve power and torque by 15% or more over stock.

So the S&B CAI I was looking at would increase my power... and then if and when i get the exhaust and tuner, plus headers i should be good to go( insert taco bell guy here)?
 
  #17  
Old 03-01-2007, 03:51 PM
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Originally Posted by DTheobald
So the S&B CAI I was looking at would increase my power... and then if and when i get the exhaust and tuner, plus headers i should be good to go( insert taco bell guy here)?
Yep! Anytime you bring more into the engine you have to balance it by allowing that extra air out (if you want the most bang for your buck). A matched set of exhaust and headers will allow you to do that.

Think of the engine as a big air pump. If you install a bigger inlet, then you have to increase the outlet as well. Otherwise the extra air backs up and causes the pump to lose power.
 
  #18  
Old 03-01-2007, 04:26 PM
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What causes the exhaust to backfire or pop when letting off the accelerator?
 
  #19  
Old 03-01-2007, 05:31 PM
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Originally Posted by DTheobald
What causes the exhaust to backfire or pop when letting off the accelerator?
Unburned fuel/air mixture passes into exhaust system then ignites when it touches the hot exhaust.

 
  #20  
Old 03-01-2007, 06:25 PM
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Originally Posted by Droog
Unburned fuel/air mixture passes into exhaust system then ignites when it touches the hot exhaust.

How would you assure that this doesn't happen? i want to be able to rev the engine and not have the popping after math
 
  #21  
Old 03-01-2007, 10:25 PM
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Originally Posted by DTheobald
How would you assure that this doesn't happen? i want to be able to rev the engine and not have the popping after math
It's almost next to near impossible to do on the 5.4L IMO. . 5.4s don't like to be revved without a load on them, ie: not driving. My true dual Flowmasters pop when I rev it up, especially cold. However, I can go WOT all day long driving and they won't ever pop.
 
  #22  
Old 03-01-2007, 11:06 PM
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Originally Posted by DTheobald
How would you assure that this doesn't happen? i want to be able to rev the engine and not have the popping after math
As Thumper said it's pretty much impossible to do. Back in the old days you could manually lean out the fuel mix by turning a couple screws, but now it's all computer controlled. If you increase airflow the PCM compensates by increasing fuel to match. Some tuners allow you to connect a laptop to the truck and manually adjust things like fuel and timing. That stuff is best left to someone that is trained and knows what they're doing.
 



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