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I'm seriously considering adding Headers and a Tuner (Will get that regardless) to my current setup. As far as performance goes, I'm running a Mopar CAI, and Corsa Xtreme exhaust. My dilemma is a two pronged one. The things standing in between me and these headers are as follows 1. Will the HP & Torque added be too much to deal with on a daily basis both for myself and whomever I let drive my car under certain circumstances (I'm in college) 2. I'm currently averaging 15 MPG and I'm not exactly thrilled with that as it is, what should I expect my MPG to drop too under normal circumstances with the addition of said headers. As always, thank you guys for your opinions and advice :beerchug:
 

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What headers do you want to add and why?

It's not going to add any meaningful HP on your current set-up even with a tune. The stock headers flow very well for the stock engine and unless you start adding heads and a cam, you won't get anything from it other than a lighter wallet. You might even lose HP depending on what you choose.
 

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Agreed... Ddaddy is completely right. Headers are a support modification... alone (or with what you've already got) they won't net you a real improvement. A tuner will, but nothing you should be worrying about. But seriously, you're talking about a car that's about 370hp to start with. A custom tune might net you another 15 if you're lucky. Not a big deal. If you're in the habit of letting friends drive a 370hp car, what's 385hp?

Mine was 350hp stock. With my mods I should be somewhere just North of 400... maybe as much as 415hp. Can I tell the difference from stock? Absolutely. Is it any more "too much" than when it was stock? Not really. Anyone who's irresponsible at 415hp would have been just as likely to wrap it around a pole when stock.

It's not like it's a Hellcat or anything... <Grin>
 

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Like said, forget the headers. Not any gains unless you get a cam and even Shorties with a Cam produces little gain.

I dyno'd on a Dynojet 315 rwhp/ 338 ft-lbs completely stock with the Daytona. I put on the K&N 63 series CAI, Dynomax Superturbo catback and JBA High Flow cats. With the Diablo tune and those mods I dyno'd 337/368. With those mods and a custom 91 tune by Johan (Diablotoona) 343/379. With the Hemifever 91 tune I got 346/382.

Good results over stock but not anything to be worried about with respect to daily driving. My mpg stayed the same. Did not improve but did not get worst. IMO the High Flows gave the car the most improvement out of those mods back then.
 

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Discussion Starter #5
Thanks for the info guys, I'm kind of at a crossroads now, what should I get next instead of headers? I'm about to sell my bike, and would want to put roughly 2k, if not less, into my car. What should I do?



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Dude, get the headers. You will be happy with them. Forget about dyno numbers. Your car will thank you for letting her breathe easier. So install the headers but get a tune as well. Like said above, not much in the hp number gain, but the stock manifolds on the 5.7L are terrible and anything you do in the future will need to have breathing room, which is exactly what some shorties will do for you car.

Here's a few side by sides:







 

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Thanks for the info guys, I'm kind of at a crossroads now, what should I get next instead of headers? I'm about to sell my bike, and would want to put roughly 2k, if not less, into my car. What should I do?



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My advice, get the Diablo tuner and pocket the rest for a latter date if your in college. A lot of performance modding depends on what your ultimate goals are for the ride HP wise. Having a goal for HP/TQ in mind helps and can definitely save you $$. There are also plenty of cosmetic mods you could do.:beerchug:

With regards to the shorties mentioned above, google and/or search the threads about performance gains at the track or on a dyno for the Eagle 5.7L. You will not find any good data for stock vehicles that put on shorties. It will all be the butt dyno results. IMO they have to justify the cost some way. I put on Shorties along with my MM Custom Cam and only gained 22 RWHP with both. The shorties did nothing for performance. I just went to Longtubes and got the gains that are expected.
 

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Thanks for the info guys, I'm kind of at a crossroads now, what should I get next instead of headers? I'm about to sell my bike, and would want to put roughly 2k, if not less, into my car. What should I do?
My advice, get the Diablo tuner and pocket the rest for a latter date if your in college. A lot of performance modding depends on what your ultimate goals are for the ride HP wise. Having a goal for HP/TQ in mind helps and can definitely save you $$. There are also plenty of cosmetic mods you could do.:beerchug:
Sounds good...
 

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I'm a little confused with all this talk about headers not gaining any HP. I know the SRT8 stock exhaust manifolds are basically shorty headers so it's pointless to replace them with anything other than long tubes, but the 5.7 stock exhaust manifolds, or logs as some like to refer to them as, are obviously restrictive and poor flowing. How could a properly designed shorty header, like JBAs, not gain anything? They're better flowing, have bigger primary tubes (well duh the logs have pretty much none), better collecting at the mid-pipes and if you get the coated ones should help keep engine temps down. I don't see how that wouldn't equate to additional HP?
 

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It does equate to an increase in HP if you get a good tune with them. Plus you get a nice change in tone from the engine. I personally couldn't get into the 13s until I installed shorties. I went from 14.0 to 13.7 on shorties and an updated tune alone. No other mods were done between those races. A cam came next and that shaved another two and a half tenths off my time. So new headers, whether long or short are definitely necessary if you plan on more engine work with the 5.7L.


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Good point. I assumed everyone knows a tune will always net you the most HP from any new mod but I can't assume everyone knows that. I have a set of JBA titanium shorty headers sitting in my garage waiting to be installed. I already have a catback and JBA hi-flow mids so I'm hoping the installation cost will be worth it because if I gain nothing I'll be pissed lol.
 

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I'm a little confused with all this talk about headers not gaining any HP. I know the SRT8 stock exhaust manifolds are basically shorty headers so it's pointless to replace them with anything other than long tubes, but the 5.7 stock exhaust manifolds, or logs as some like to refer to them as, are obviously restrictive and poor flowing. How could a properly designed shorty header, like JBAs, not gain anything? They're better flowing, have bigger primary tubes (well duh the logs have pretty much none), better collecting at the mid-pipes and if you get the coated ones should help keep engine temps down. I don't see how that wouldn't equate to additional HP?
With the stock Eagle 5.7L you may gain 5-8 rwhp. The reason many state there is no difference is with a 370 hp factory rated engine, you will not feel the 5-8 rwhp. You can get the same increase in hp by putting on High Flow JBA cats. There are many who have put on shorties and went to the track and saw no difference in their times. Like I said above, I put on the Shorties with a custom grind cam and only gained 22 rwhp. IMO that came from the Cam because I already had the High Flows on.

This is with the stock engine. The manifolds may be a little restrictive but the cost to buy and put on shorties unless you do the work yourself does not give you a good bang for the $$. High Flows just bolt right up to an aftermarket catback and can be done in the garage by most.
 

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Discussion Starter #13
My personal goal is ~450-475 HP at the crank. But all of this talk about pipes is confusing me, are headers only worth the money if I'll be doing further engine work? But alone they aren't worth the cost


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Good point. I assumed everyone knows a tune will always net you the most HP from any new mod but I can't assume everyone knows that. I have a set of JBA titanium shorty headers sitting in my garage waiting to be installed. I already have a catback and JBA hi-flow mids so I'm hoping the installation cost will be worth it because if I gain nothing I'll be pissed lol.
There is only a couple of ways to find out. Go to the track and get your best time before and after install or get a before and after dyno. I prefer using a dyno to measure performance increases with mods. If you use the same dyno, same operator, do the run in the same gear with no software upgrades to the dyno and get as close to the same temps for both, you will be able to tell if the mod was worth the $$ or not. I have tried many on this Hemi and have lost $$ in the process. Good luck:beerchug:
 

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My personal goal is ~450-475 HP at the crank. But all of this talk about pipes is confusing me, are headers only worth the money if I'll be doing further engine work? But alone they aren't worth the cost


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Here is a link to my build thread. I hope that it will save some folks $$ if they plan to stay NA. Before the Longtube Headers I was at 450 Crank (With JBA Shorties and HF's) after the Longtubes were installed I reached around 485 on my last dyno. (412 rwhp)

The other option and the way I would have gone "if I had known and if it were available at the time" would have been the Eldebrock Supercharger. Simple/Moderate bolt on and 100 hp gain running 7 psi which is safe for the 5.7L.

http://www.chargerforums.com/forums/showthread.php?t=235713&highlight=
 
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