Stock CB with DP or stock DP with aftermarket CB

Which one provides more HP gains?

CB - catback
DP - downpipes

The consensus on this forum is the exhaust modifications are done mainly for sound, not performance gains. Most of the louder DPs throw CELs due to their free flowing cats. With CBs, they can be very loud if you remove the factory resonator, but they typically do not cause CEL issues.

I am leaving my factory DPs and resonator. I will add SPD Turbo Adapters and a Flowmaster muffler to give the truck a deeper growl on acceleration. I am leaving the factory tailpipes because the big flat black tips look good enough to me.

I would agree, probably not much difference but I think stock DP with a CB system might be a little more effective at reducing back pressure. Without changing the amount of air that can get in, i.e. CAI or some kind of forced induction, back pressure isn't really an issue.

Cat back will give you only sound change. Downpipe will give you a slight increase in hp and some sound change.

The key is turbo adapters and opening up that area for flow. And Tuning.

Turbo adapters have given the biggest gains from what I have seen on my dyno. Down stream in the exhaust hasnt made much difference in horsepower. A pick up of around 5-10 hp with downpipes has been what I have seen on our dyno before and after. Larger pipes and free flowing cats will make it run more effecently for sure (cooler exhaust temp) and change the sound a little.

Sigmoid said:

I would agree, probably not much difference but I think stock DP with a CB system might be a little more effective at reducing back pressure. Without changing the amount of air that can get in, i.e. CAI or some kind of forced induction, back pressure isn't really an issue.

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Sorry, just realized you were asking about a gen 2.

khcdave said:

Turbo adapters have given the biggest gains from what I have seen on my dyno. Down stream in the exhaust hasnt made much difference in horsepower. A pick up of around 5-10 hp with downpipes has been what I have seen on our dyno before and after. Larger pipes and free flowing cats will make it run more effecently for sure (cooler exhaust temp) and change the sound a little.

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How much HP gain have you seen on your Dyno from the Turbo Adapters? I saw the information on SPDs website, but I prefer to hear from an independent source. I considered their downpipes, as well, but I want to avoid CEL issues when I remove my tune to take it into the dealer.

TXRaptor said:

How much HP gain have you seen on your Dyno from the Turbo Adapters? I saw the information on SPDs website, but I prefer to hear from an independent source. I considered their downpipes, as well, but I want to avoid CEL issues when I remove my tune to take it into the dealer.

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Removing your tune to take it to the dealer is a waste of time. Dealers can't see what tune you have only how many times it's been flashed. Seeing 2 or 3 flashes isn't abnormal. But if you start taking your tune on and off all the flashes add up and it looks suspicious.

TXRaptor said:

How much HP gain have you seen on your Dyno from the Turbo Adapters? I saw the information on SPDs website, but I prefer to hear from an independent source. I considered their downpipes, as well, but I want to avoid CEL issues when I remove my tune to take it into the dealer.

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Picked up 18 at the wheels on my dyno. Bone stock on my dyno is about 335 to the wheels. With mpt tune, spd adapters and S&B intake it makes 396-403.

All the tunes I have tested make around the same power with the adapters. Adding down pipes got a 5-10 hp increase.

reaper1441 said:

Removing your tune to take it to the dealer is a waste of time. Dealers can't see what tune you have only how many times it's been flashed. Seeing 2 or 3 flashes isn't abnormal. But if you start taking your tune on and off all the flashes add up and it looks suspicious.

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Thanks, that makes sense. What about an issue that requires them to reflash your truck due to an update from Ford? Does that mean they cannot overwrite the MPT part of the tune?

---------- Post added at 08:04 PM ---------- Previous post was at 07:53 PM ----------

khcdave said:

Picked up 18 at the wheels on my dyno. Bone stock on my dyno is about 335 to the wheels. With mpt tune, spd adapters and S&B intake it makes 396-403.

All the tunes I have tested make around the same power with the adapters. Adding down pipes got a 5-10 hp increase.

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60-70 HP at the wheels translates to about ?? at the crank?

How much HP do you think the S&B adds?