bigger TB=bigger performance???
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From: Arkansas
bigger TB=bigger performance???
as i understand it a 351 with SD will do better with a high flow air filter in original air box then with a injection kit because the injection kit is TOO high flow
if this is true then y would a bigger throttle body help it seems like if the engine performs best with a certain amount of vac. pressure then bigger throttle bodies would not help performance because just like the injection kit they would allow to much air in
maybe im gettin this all wrong? lets hear from the experts
if the TB lets in more air without letting in too much air could a custom built air box not do the same ... say one a little more open but not too much it would definalty be cheaper than a performance TB
if this is true then y would a bigger throttle body help it seems like if the engine performs best with a certain amount of vac. pressure then bigger throttle bodies would not help performance because just like the injection kit they would allow to much air in
maybe im gettin this all wrong? lets hear from the experts
if the TB lets in more air without letting in too much air could a custom built air box not do the same ... say one a little more open but not too much it would definalty be cheaper than a performance TB
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From: Medford, OR
The reason a high flow filter in the factory airbox is better than an open filter is that the open filter is sucking in hot underhood air instead of the cooler air inside the airbox. The inscreased flow is good, but the hotter air hurts your performance. That is why a lot of people will suggest a K&N filter in the original box with some type of thermal wrap.
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Joined: Jun 2004
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From: Mid-Missouri
Is this 351 equipped with a MAP or MAF computer?
Either way, the design of the engine determines the optimum air flow. They can't take in more air than they need if they are normally aspirated.
MAF is more flexible and can be programmed for performance add-ons more easily.
MAP is more limited due to the tables and the available input from the sensors, (MAP, ACT, CTS and 1 O2 sensor).
In short, you can't give these engines too much air unless you are forcing it in via a SC or a turbo. If that is the case, you'd have to use MAF computer and reprogram. I believe MAF also has 2 or more O2 sensors in the system to give more feedback to the EEC on the fuel/air ratio.
Changing the airbox or filter will reduce turbulance and allow better flow.
Cooling the air intake via a ram and remote airbox may increase power due to the cooler/denser air entering the combustion chamber. You may see a drop in mileage though if everything is not tuned properly. The computer will compensate for the cooler air by increasing the fuel injected into the chamber. The end result is a few more HP.
Either way, the design of the engine determines the optimum air flow. They can't take in more air than they need if they are normally aspirated.
MAF is more flexible and can be programmed for performance add-ons more easily.
MAP is more limited due to the tables and the available input from the sensors, (MAP, ACT, CTS and 1 O2 sensor).
In short, you can't give these engines too much air unless you are forcing it in via a SC or a turbo. If that is the case, you'd have to use MAF computer and reprogram. I believe MAF also has 2 or more O2 sensors in the system to give more feedback to the EEC on the fuel/air ratio.
Changing the airbox or filter will reduce turbulance and allow better flow.
Cooling the air intake via a ram and remote airbox may increase power due to the cooler/denser air entering the combustion chamber. You may see a drop in mileage though if everything is not tuned properly. The computer will compensate for the cooler air by increasing the fuel injected into the chamber. The end result is a few more HP.
Last edited by lmadore; Aug 5, 2004 at 02:13 PM.
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it is not MAF which is y i was thinking the TB would be a waste
but im still confused can i get a little more power with a little higher air flow or a little cooler and not loose the mpg's
but im still confused can i get a little more power with a little higher air flow or a little cooler and not loose the mpg's
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Joined: Jun 2004
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From: Mid-Missouri
Probably not a noticeable amount of power.
TB might give you a little more torque off the line but nothing worth what they cost.
Cooler air is usually better regardless of noticeable power increase.
Just make sure that the engine is tuned and not throwing codes. You probably won't see a decline in mileage unless you are alway getting on it to see if you can feel the difference in HP. More HP tends to make people push their vehicles harder. This causes decrease fuel mileage.
I installed a bunch of performance mods on my last truck. The problem was, I notice that my driving habit changed with the increased power and I seemed to be hitting the gas station a bit more often.
It's a trade-off.
TB might give you a little more torque off the line but nothing worth what they cost.
Cooler air is usually better regardless of noticeable power increase.
Just make sure that the engine is tuned and not throwing codes. You probably won't see a decline in mileage unless you are alway getting on it to see if you can feel the difference in HP. More HP tends to make people push their vehicles harder. This causes decrease fuel mileage.
I installed a bunch of performance mods on my last truck. The problem was, I notice that my driving habit changed with the increased power and I seemed to be hitting the gas station a bit more often.
It's a trade-off.
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