GEN 2 Is a 3" Exhaust Really Worth It?

Is a 3" cat back system alone worth $800 - $1400 without addressing upstream?


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xrocket21

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No, I'm having the SPD turbo adapters installed already.

According to SPD, "100% stock 2016 F150 3.5L Ecoboost with just SPD's adapters installed had an +21HP and +17TQ increase at the rear wheels! See dyno. A 100% stock 2017 F150 Raptor made +24HP and +43lbs of TQ at the rear wheels.
Kind of hard to read the dyno sheet, since it blurs out when enlarging.....but FWIW.. https://www.spdperformance.com/image/cache/catalog/ebay_connector/GO4AAOSwJ7RYUcl6_$_57-500x500.jpg


that was directed toward the other guy, but hell yeah!

I have em on mine.
 
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WillieFlo

WillieFlo

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The greater the diameter of an exhaust system, the slower the exhaust gasses move. Under some circumstances the exhaust flow can actually stall in an exhaust tract that too large for the engine. That's a bad thing.

I would believe that going from 2 1/2” to 4” could be detrimental, but I hardly think going from 2.75” to 3” will hurt, unless Ford Perf maximized it to be on the brink of stalling.....doubt it! Likely the exhaust was necked down for emissions reasons and the EPA.....
 

Ruger

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I would believe that going from 2 1/2” to 4” could be detrimental, but I hardly think going from 2.75” to 3” will hurt, unless Ford Perf maximized it to be on the brink of stalling.....doubt it! Likely the exhaust was necked down for emissions reasons and the EPA.....

Unless you're good at fluid dynamics, Willie, you're guessing. Why don't you take the guesswork out of this and contact Ford Performance with your conjecture. Ask them if a 3" system would stall, and while you're at it ask them if any benefit will be realized.
 

HoldenTX

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Unless you're good at fluid dynamics, Willie, you're guessing. Why don't you take the guesswork out of this and contact Ford Performance with your conjecture. Ask them if a 3" system would stall, and while you're at it ask them if any benefit will be realized.
Actually it would be much better for the AFE, Corsa, Borla etc. People to explain what engineering they did and the conclusions they came to when designing their products. Presumably Ford spends millions on engineering and has access to the latest and greatest flow modeling software and came to the conclusion that 2.75" was the best bang for buck. Saying a wider pipe will increase flow is like saying a firehose connected to the side of your house will let you water the garden faster than a regular garden hose. That could be true if the water pressure at your house would fill a firehose.
Anyhow, beyond the sound improvements I really haven't seen any of the aftermarket exhaust makers claim any scientific improvements. But I'd love to hear more from them on what they did to improve flow and how it was measured etc.
I've got a feeling everyone went with 3" because everyone else did....or maybe that was needed for the best sound.


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Ruger

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^^^I had a discussion with an AIRAID tech. He was quite informative and patient in explaining his firm's flow bench methodology. He did not, however, try to explain the math. For good reason - only an engineer would grasp it.

There's nothing wrong with calling AFE, Corsa, Borla, etc. and asking a tech your questions.
 

HoldenTX

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I'd love to hear more about AirRaids science. Don't get me wrong. I'd love to know I can get a performance improvement, I just haven't seen (in the limited amount of web surf research that I have done) and reason to think these offer any improvements beyond audio.
The other thing I'd like to hear is what these companies have done for the Gen2 Raptor specifically. The Raptor is designed differently than the regular F150...and different to other makes and models. So just because you made improvements on a Chevy Silverado with an exhaust doesn't mean the Gen2 Ford Raptor will see any gains. So what is unique about these exhausts that take into account the Raptors unique DNA?

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Quaesta

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I spoke to FP and was told there is no hp gain from either of their exhausts only sound differences.
 

HoldenTX

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I spoke to FP and was told there is no hp gain from either of their exhausts only sound differences.

I think FP uses Borla to make their exhausts, so that would presumably rule out Borla from offering any performance improvements.
 

GrayGhostDog1

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It does not matter what type of modern engine your ride has... V8, V6, 4-banger, etc. ... if there is some type of performance gain from an axle-back or catback, it is negligible in the hp/tq arena. Changing to those set-ups are just for sound... PERIOD. Most OEM exhausts are very quiet and they have been getting quieter every year. FOMOCO is not the only co. piping "fake" sound into the cabin of their rides. OEM's have been battling with keeping power to the ground due to power-robbing restrictions(catalytic converters and other do-dads that keep pollution in check), noise reducing components, and safety features... these things add more weight, too.

Do an axle-back? You want more volume... Do a catback? You are looking for even more volume... resonator, h-pipe, x-pipe changes? You are looking to change the sound characteristics and still a bit more volume. It's only when you start addressing things past that where you might net real performance gains and whether those modifications are ultimately worth doing.

Gen 2 Raptor will NEVER sound like a V8, no matter which exhaust option you choose... not saying that I do not like the sound of the Gen 2 Raptor. I actually really like the tone!
 
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