Kegger Mod question
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Rookie
Joined: Dec 2009
Posts: 50
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From: north carolina
Kegger Mod question
I done the kegger mod but havent put it on yet, waiting for tax money to buy the Hughes kit. With the mods i have and a superchip do yall think that i will lose any bottom end? If so what else should i get to help?
Veteran
Joined: Mar 2007
Posts: 419
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Dont know much about the kegger mod but there is another place that sells plenum plates that you might want to look at.Hughes is getting bashed a little bit for customer service.
http://www.apsprecision.com/menu.html
http://www.apsprecision.com/menu.html
Grand Champion
Joined: Nov 2004
Posts: 6,099
Likes: 6
From: Colorado
Some will argue that you might lose low end. Problem is, no one has any data to back that up because no one i've ever seen has done a before and after dyno of the kegger mod. The theory they are using to base this claim on is that if you make the plenum space bigger by cutting away the runner material during the kegger mod, you lose bottom end. They feel that as the plenum space gets bigger, your low end gets worse or power is moved up the powerband. So some will put a turtle, epoxy, or some other homemade item in the intake to take up space so the overall plenum volume is less. They all have reported good results with this, but again no before and after dyno tests to prove much of anything. Just a bunch of personal opinion. And that's all I have to offer to. My opinion after having done this mod was that I did not lose any low end. I feel it is actually better. But I admit that my opinion is scewed because the reason I had my intake off to begin with was because of a blown plenum gasket. So my before and after was a comparison of a blown plenum to a modded newly repaired plenum. All I know is, I have plenty of bottom end.
As far as if you lose low end because of more plenum volume, I personally believe the opposite is true. First, I once read an automotive science journal article about the impacts of modifying plenum volume and runner lengths on intake manifold designs. The focus of the article was on emissions control, but they did note that as the plenum volume increased, low end torque (they said from 1200 rpm to 2300 rpm) increased. As the plenum got smaller, low end dropped off, but top end power got better. They also indicated that the longer the runners, the better the powerband, but only if total runner length didn't exceed that needed to ensure smooth and matched air flow to the intake pulses. In otherwords, too much runner was as bad as too short of runners. There was a long discussion about adjustable plenums. One concept was basically a bladder in the intake that would inflate and deflate to decrease and increase the amount of space in the plenum. For low end torque, the bladder would be fully deflated, allowing the most plenum volume. As you got up into the power band, the bladder would inflate, restricting plenum volume, thus making more top end power. Another concept used adjustable partitions in the intake to increase and decrease the plenum space.
Secondly, consider the M1 and Airgap intakes. They have basically no plenum volume space. The main complaint with these intakes is - loss of low end.
Third, people say that they have improved their low end in the plenum style intakes by putting in a turtle or some other mechanism to take up space. Personnally, I don't think the decreased space is what is making them feel results, I think it is rather that whatever they are putting in the intake is usually shaped in such a way that it is promoting better air direction into the runners. This improved air flow is what is giving them perceived good results from the turtle, not the decrease in plenum space - in my opinion.
And last, consider that these trucks came factory with a large plenum intake to begin with. Why? If large plenums contribute to loss of low end, why would Chrysler have put that in a truck that weights over 5000 lbs with a small v8. I think the reason is they were trying to get as much low end torque out of these engines as possible, so they went with a large plenum intake manifold rather then another design.
I want to say too that when the great HankL used to talk about this topic, he would say the same thing, but i'd have to find some of his old posts before I quote him on that.
As far as if you lose low end because of more plenum volume, I personally believe the opposite is true. First, I once read an automotive science journal article about the impacts of modifying plenum volume and runner lengths on intake manifold designs. The focus of the article was on emissions control, but they did note that as the plenum volume increased, low end torque (they said from 1200 rpm to 2300 rpm) increased. As the plenum got smaller, low end dropped off, but top end power got better. They also indicated that the longer the runners, the better the powerband, but only if total runner length didn't exceed that needed to ensure smooth and matched air flow to the intake pulses. In otherwords, too much runner was as bad as too short of runners. There was a long discussion about adjustable plenums. One concept was basically a bladder in the intake that would inflate and deflate to decrease and increase the amount of space in the plenum. For low end torque, the bladder would be fully deflated, allowing the most plenum volume. As you got up into the power band, the bladder would inflate, restricting plenum volume, thus making more top end power. Another concept used adjustable partitions in the intake to increase and decrease the plenum space.
Secondly, consider the M1 and Airgap intakes. They have basically no plenum volume space. The main complaint with these intakes is - loss of low end.
Third, people say that they have improved their low end in the plenum style intakes by putting in a turtle or some other mechanism to take up space. Personnally, I don't think the decreased space is what is making them feel results, I think it is rather that whatever they are putting in the intake is usually shaped in such a way that it is promoting better air direction into the runners. This improved air flow is what is giving them perceived good results from the turtle, not the decrease in plenum space - in my opinion.
And last, consider that these trucks came factory with a large plenum intake to begin with. Why? If large plenums contribute to loss of low end, why would Chrysler have put that in a truck that weights over 5000 lbs with a small v8. I think the reason is they were trying to get as much low end torque out of these engines as possible, so they went with a large plenum intake manifold rather then another design.
I want to say too that when the great HankL used to talk about this topic, he would say the same thing, but i'd have to find some of his old posts before I quote him on that.