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nastang87xx

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I'd say lets take a look at the real world and it doesn't matter 7/8 or 3/4 because we aren't making enough power to take advantage of that bigger diameter regardless of RPM. 1 3/4" will be perfectly fine for most of us mortals. Come back with that 7/8 nonsense when someone is making 1000 horsepower.
 
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The reason most coyote headers are 1-7/8 are because of the supercharger
 

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I'd say lets take a look at the real world and it doesn't matter 7/8 or 3/4 because we aren't making enough power to take advantage of that bigger diameter regardless of RPM. 1 3/4" will be perfectly fine for most of us mortals. Come back with that 7/8 nonsense when someone is making 1000 horsepower.
Multiple of our vendors say the 2" is better suited for 1000whp. 1-7/8 is better.
 

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I'm lost...what supercharger? You can add one sure but I'd say the majority of people buying headers honestly are full bolt on guys, not FI'ed.
What I'm telling you is that for this engine a 1-3/4" header is big enough. Its naturally aspirated. The reason most aftermarket headers are 1-7/8 for the coyote is because most people put a supercharger on them. If I was making a set for my GT350 voodoo myself I would make them 1-3/4" and step them to 1-7/8" a step header uses two sizes of tubing. Using both size of tubes can help depending on the rpm and power band and also depending on its aspiration. With the voodoo being high compression I myself if I made them for this engine would like to try 1-3/4 stepped to 1-7/8.
 

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Arh is arguably the best exhaust/headers you can buy for domestic v8s. Followed by kooks. Subbed. The x pipe on these necks down a lot. Looking forward to see the gains made.
Exactly, I know for a fact that the vipers racing headers are from arh.
 

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The reason most aftermarket headers are 1-7/8 for the coyote is because most people put a supercharger on them.
I'm not so sure about that...that's possibly the perception but in the real world? Out of all the 5.0's in my area, I know TWO guys with FI, one with a Paxton and another with a '13 RS3 both with factory cats. On the other hand, I can count probably a dozen NA Bolton guys with long tubes including myself. The only reason why I have 1 7/8" is because I was able to get them for much cheaper than the 1 3/4 when I bought them. Just ran into a good sale.

But 7/8" vs 3/4" doesn't really mean more power with FI either. It's a lot more complex than that. It's about overall power levels, desired application, compression, head design, and bore and stroke. FI vs NA is just a fraction of the entire equation.


What I'm telling you is that for this engine a 1-3/4" header is big enough. Its naturally aspirated...If I was making a set for my GT350 voodoo myself I would make them 1-3/4" and step them to 1-7/8" a step header uses two sizes of tubing. Using both size of tubes can help depending on the rpm and power band and also depending on its aspiration. With the voodoo being high compression I myself if I made them for this engine would like to try 1-3/4 stepped to 1-7/8.
I'm aware of the technicals regarding headers.

Anyway, going back to the original point though, I don't even know if a stepped header is necessary either. If you're really trying to squeeze out every ounce of realistic power, I'd start with the tune.
 
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I'm not so sure about that...that's possibly the perception but in the real world? Out of all the 5.0's in my area, I know TWO guys with FI, one with a Paxton and another with a '13 RS3 both with factory cats. On the other hand, I can count probably a dozen NA Bolton guys with long tubes including myself. The only reason why I have 1 7/8" is because I was able to get them for much cheaper than the 1 3/4 when I bought them. Just ran into a good sale.

But 7/8" vs 3/4" doesn't really mean more power with FI either. It's a lot more complex than that. It's about overall power levels, desired application, compression, head design, and bore and stroke. FI vs NA is just a fraction of the entire equation.

Just because someone buys and installs larger diameter tube headers doesn't mean they are making more power. As you know the 5.0 is a cross plane. The exhaust scavenging isn't as good as a flat plane. If the header tube is to big the scavenging velocity will not remove the burnt exhaust from the cylinder efficiently.
Your statement above is just arguing my comments I already said. I already said it depends on compression bore stroke cam overlap etc. I also said a boosted or psi engine can use large tube headers because the incoming volume of forced induction is grater. You wouldn't put a 1-7/8 or 1-3/4" header on a 8.0:1 engine without a power adder.


I'm aware of the technicals regarding headers.

Anyway, going back to the original point though, I don't even know if a stepped header is necessary either. If you're really trying to squeeze out every ounce of realistic power, I'd start with the tune.
Why would you tune before headers? That's ridiculous. The increased breathing will definitely change the efficiency of the tune. Don't bet your lunch against step tube headers. You'd be surprised in what you may find.
 

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Anyway, going back to the original point though, I don't even know if a stepped header is necessary either. If you're really trying to squeeze out every ounce of realistic power, I'd start with the tune.

+1 :thumbsup:
 

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Why would you tune before headers? That's ridiculous. The increased breathing will definitely change the efficiency of the tune.

Because you can update a tune super easy with just a datalog and email. Adding headers is quite a bit more involved, plus you get to see exactly what the headers offer in terms of performance gain by themselves.
 

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Why would you tune before headers? That's ridiculous. The increased breathing will definitely change the efficiency of the tune. Don't bet your lunch against step tube headers. You'd be surprised in what you may find.
How do you know what to find if you don't know what you're looking for in the first place? Baseline it. Tune it. Analyze the tune. Add a focused purpose build header based on the findings of the tune. I'm not saying don't get headers, just figure out what you're working with BEFORE you choose a header design. I'm sure ARH will do pretty much whatever you want too since you'll be FTM.
 

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There's two trains of thought here:

First one would be, "I am buying a header/part and I will tune around the header."

Second one would be, "I have baselined and I understand what my performance goals are and therefore I can build a header/part around my goals, not my goals around the header (or whatever performance part for that matter)."

The second sounds like a more focused strategy. But you're First to Market and it's your money so go for whatever you think is right. I'm just trying to offer suggestions or insight particularly since this is such a new platform. We have NO clue how it's going to respond.
 
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I'm baselining the stock engine. Then the JLT. Then the headers and tune. In the same day.
 
 




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