347 EFI Low Power

deathb4dismount

Crap, didn’t realize my crotch was in that picture
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You could nickel and dime 25ish hp with bolt ons. 80MM MAF, power pipe 75 MM TB, Systemax II and long tubes, but that wont feel like nickels and dimes to your pockets. Plus it still will drive like a car with a mismatched converter. Or you could take it to another tuner and magically make a friendly 20 more hp. Some Dynos are stingier than others. Was this on a Mustang Dyno or Dynojet? At the end of the day I'd take a hard shifting fun 320 HP over a wet noodle shifting 350HP. Spend the $$ on the converter then go from there.
 
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90sickfox

Wasn't a pretty sight...and I've got big hands
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I believed long tubes were always better until I read this article. There was another on in one of the popular mustang mags years ago, too. The shorties made more power in the streetable range due to exhaust scavenging. I'm sure that design and tube size had a lot to do with that. Wish I could find the old paper article.

 

General karthief

wonder how much it would cost to ship you a pair
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I believed long tubes were always better until I read this article. There was another on in one of the popular mustang mags years ago, too. The shorties made more power in the streetable range due to exhaust scavenging. I'm sure that design and tube size had a lot to do with that. Wish I could find the old paper article.

you better go back and read that article again.
When equipped with the long-tube headers, the power output of the 351W improved from 404 hp and 413 lb-ft to 420 hp and 429 lb-ft of torque. The long-tube headers improved the power output through the entire rev range,
keep in mind this is a larger 'air pump' so results will very with miss matched parts but over all long tubes win, sometimes the 'win' is small.
Oh, and the article stated '1" primaries ' but they are 1 5/8
Typo I'm sure.
 
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90sickfox

Wasn't a pretty sight...and I've got big hands
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you better go back and read that article again.
When equipped with the long-tube headers, the power output of the 351W improved from 404 hp and 413 lb-ft to 420 hp and 429 lb-ft of torque. The long-tube headers improved the power output through the entire rev range,
keep in mind this is a larger 'air pump' so results will very with miss matched parts but over all long tubes win, sometimes the 'win' is small.
Oh, and the article stated '1" primaries ' but they are 1 5/8
Typo I'm sure.
Yeah I read that. On that application it made power all across the board but if the design of the headers was different the result could be different. That's what the old paper article was saying. I found ( what I think is the article )but the link does not work.

Screenshot_20220712-201024_Chrome.jpg
 

96pushrod

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Yeah I read that. On that application it made power all across the board but if the design of the headers was different the result could be different. That's what the old paper article was saying. I found ( what I think is the article )but the link does not work.

Screenshot_20220712-201024_Chrome.jpg
Would be an interesting read if you can find it. Not often you see a short tube perform better.
 

90sickfox

Wasn't a pretty sight...and I've got big hands
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Would be an interesting read if you can find it. Not often you see a short tube perform better.
Now that I've had time to really think about it...I think the mid length won the challenge in all categories. It was probably due to design. Headers have come a long way over the years. The designs have definitely changed with newer technology and manufacturing processes. Back when that article was written the E cam was probably hailed as the best street camshaft.
 
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General karthief

wonder how much it would cost to ship you a pair
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Here is a thread from a past member that has been building headers for cars since the beginning, or close to. He likes the mid length type, mostly racing stuff but does get into street headers too.
 
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96pushrod

I think they're a little easier to get off
May 15, 2018
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Here is a thread from a past member that has been building headers for cars since the beginning, or close to. He likes the mid length type, mostly racing stuff but does get into street headers too.
It’s sad to see the only guy who made headers for rci pass away.
 
You could nickel and dime 25ish hp with bolt ons. 80MM MAF, power pipe 75 MM TB, Systemax II and long tubes, but that wont feel like nickels and dimes to your pockets. Plus it still will drive like a car with a mismatched converter. Or you could take it to another tuner and magically make a friendly 20 more hp. Some Dynos are stingier than others. Was this on a Mustang Dyno or Dynojet? At the end of the day I'd take a hard shifting fun 320 HP over a wet noodle shifting 350HP. Spend the $$ on the converter then go from there.
What i am ending up doing is porting my throttle body and intake manifold. I am receiving my valve body this week and will install that. I need to get my driveshaft balanced so when that happens I will put a 3000 or so stall in it. I should make 340ish to the wheels if my intake was truly the choke point and it should be based off of flow charts. Unfortunately no long tubes cause I am not about to deal with that pain on an Aod and then I would have to get new h pipe etc
 

TOOLOW91

If you're the village idiot what's that make me?
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What i am ending up doing is porting my throttle body and intake manifold. I am receiving my valve body this week and will install that. I need to get my driveshaft balanced so when that happens I will put a 3000 or so stall in it. I should make 340ish to the wheels if my intake was truly the choke point and it should be based off of flow charts. Unfortunately no long tubes cause I am not about to deal with that pain on an Aod and then I would have to get new h pipe etc
You guessing on the converter or did you actually talk to someone at one of the converter places ?
 
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Bullitt347

I have been doing it wrong this whole time
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Here is a thread from a past member that has been building headers for cars since the beginning, or close to. He likes the mid length type, mostly racing stuff but does get into street headers too.
George Klass made the headers for my race car. 2"- 2 1/8" stepped with a 4" collector. Not cheap, work great. Fit great, PITA to install.
 

TOOLOW91

If you're the village idiot what's that make me?
15 Year Member
Nov 29, 1999
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S.I.NY
George Klass made the headers for my race car. 2"- 2 1/8" stepped with a 4" collector. Not cheap, work great. Fit great, PITA to install.
Same with mine . Fit mint . They suck to install - for what he used to charge I think he should’ve offered stainless for a bit more
 
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