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Here's some thing kinda funny and wanted to know if this is true. I was at the shop talking to a guy there about getting long tube headers and an o/h pipe. The guy told me it's kind of a trade off. He told me with forced induction he has seen cars loose about .5-1.0 lb boost with headers and o/r set up but they did gain hp? Any one ever heard of this?
 

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i have long tubes an a vortech. now, i dont have before comparisons but im running 10lbs boost at 478HP and 403lbs TQ
 

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Yes this is what happens when you put long tubes on a boosted car.
 

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yup you got it. Car breathes easier, blower dont work so hard.
 

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why would you want to? Running less boost making more power is a good thing. Sure slap a smaller pulley on there but your gonna make power that will probably start pushing your luck.
 

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Your Resident Badass
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You could if you wanted, but I don't see why you want or need to.
 

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because once you start forging internals, you are able to run more boost. :)
 

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Bob The Mo'fukkin Builda!
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everyone has already said it:

less boost because of more exhaust flow and more power with the less boost. you're making everything more efficient
 

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thats why my tuner was surprised at the amount of boost/HP i got. he expected more
 

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Just think about how you measure boost. Where ever you have the most restriction thats where boost builds up. You free up your exhaust and flow more air then you will be less restrictive and lose boost pressure.

However your supercharger is still pumping out the same amount of air that it was before. You will still make a little more horsepower and say you're running less boost than that other guy with shorty headers.
 

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RIP Dennis
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Less Restriction = Less Boost = More Power
 

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When I went to longtubes I went from about 11.5 max psi to about 10.5 max psi. The low end torque suffered a bit but the peak hp went up. I went to a smaller pulley and brought the boost back up to 11.5 or so. Whoa - that made a big diff :) I got to the boost level I was at before long tubes but was now pushing much more air through the engine and making more power. I think that's the main advantage of long tubes - allows you to make more power at a given boost level.

I'm in "not too concerned if the motor blows" mode now so am willing to push it a bit further and have actually gone down a pulley size and see 12 - 12.5# boost now with the longtubes.


Here's some thing kinda funny and wanted to know if this is true. I was at the shop talking to a guy there about getting long tube headers and an o/h pipe. The guy told me it's kind of a trade off. He told me with forced induction he has seen cars loose about .5-1.0 lb boost with headers and o/r set up but they did gain hp? Any one ever heard of this?
 

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I Poop Entirely Way Too Much
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Less Restriction = Less Boost = More Power
Exactly. The headers create less restriction so more air can flow out and in turn more air can flow in. More air means more power. Air flow is measured in CFM, air restriction is measured in boost. Less restriction (boost) mean more air flow (CFM).
 

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Bob The Mo'fukkin Builda!
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don't want to destroy my engine as i'd be worried about a head getting damaged. already spend the 2 grand for heads and would be pissed if i had to buy a long block rather than a short block
 

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I Poop Entirely Way Too Much
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don't want to destroy my engine as i'd be worried about a head getting damaged. already spend the 2 grand for heads and would be pissed if i had to buy a long block rather than a short block
Why would the head be damage from more exhaust flow?
 

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this is why LT's are a very good mod for FI
on my Whipple gen 1, i have a 3.5 pulley which I rate at about 9 psi since its 10 with a gen 2.
i see about 7 psi on my gauge, i get about 449 rwhp/419 tq. i figure i lost a couple psi but picked up a few ponies.
less restriction and more power is what you want.
friend of mine with a terminator put in LT's, lost 3 psi but gained about 10 psi without retuning and no pulley change.
you dont gain a ridiculous amount of power but its better on your engine, and it sounds good too.
 
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