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  1. #1
    blownwhite03 Guest

    Question cutout =less boost

    anybody know if I put electric cutouts on with the radix if i will loose boost pressure?? in theory open up exaust, lose back pressure? add boost? what happens from longtube headers hi flow cats single camber flowmaster, to dumping out the bottom seems like the boost should be affected? anybody know magnuson well? magnuson MP112. Pulley sizes boost pressures. Can anybody give me definite answers (not just opinions) please?
    Last edited by blownwhite03; 03-27-2009 at 12:00 AM.

  2. #2
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    You won't really "lose" any boost as you will still be pushing the same amount of air. Running with a cutout may allow you to run with a smaller pulley.

  3. #3
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    Anything that improves the efficiency of the engine(make the engine breathe better/easier) will reduce the pressure in the intake, which reduces boost. That doesn't mean you are losing power, it means your engine is more efficient. That means more power. Your Radix moves a specific volume of air thru it per revolution. Think about the volume of the air you're moving thru the engine, not just the pressure. You want both.
    2001 ECSB 4x4, 5.3, Radix, 3.0 pulley, VHP Trucker cam, 216/224 .551/.551 115 lsa, 1.8 Crane roller rockers, 4L65E, Yank SC3000, 3.73, Cal-Tracs, HPTuners.

  4. #4
    blownwhite03 Guest

    Question ok...

    did you have a radix and cutouts? and on the dyno your saying that at a 3.3" pulley running say 8 pounds though exaust will make less hp then uncorked. how much more hp ? what would the 3.3" = in pounds with cutout. I was under the impression that boost = hp

  5. #5
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    Boost pressure is a measure of restriction in some ways.

  6. #6
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    I'm gonna try to explain this one more time. Any mod that increases the efficiency of your engine(heads, cam w/more lift/duration, headers, cutouts, CAI, etc.) will increase hp. It doesn't matter if you are n/a or FI. That basic principle still applies.

    You asked if adding a cutout will add hp to your setup. Since you have a flowmaster, I'll guess that it will add hp. Only a dyno will tell how much, every truck setup tests differently.

    You asked if it will change your boost level. If it does infact flow better thru cutouts than the flowmaster, then the boost pressure being measured in your intake manifold will drop. But you are still making more power due to the increased efficiency of the new setup. Remember, the Magnacharger is still spinning the same speeds as before, thus still moving the same amount of air, just with less restriction in the exhaust, so it's easier work for it.

    Now you say you want to get back to the 8 psi boost that you had before the cutouts. To do that, you need your Magnacharger to move more air(volume). To do this, you replace the pulley with a smaller diameter pulley. The typical steps are 1 psi increase per 0.1 inch smaller pulley. So, if you lost 2 psi after installing cutouts, go from your 3.3 to a 3.1 pulley, and you're back to 8 psi. Oh, and when you went from 6, back to 8 psi, you made even another gain in hp.

    Better?
    2001 ECSB 4x4, 5.3, Radix, 3.0 pulley, VHP Trucker cam, 216/224 .551/.551 115 lsa, 1.8 Crane roller rockers, 4L65E, Yank SC3000, 3.73, Cal-Tracs, HPTuners.

  7. #7
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    I like that ^^^

  8. #8
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    Thanks GG. You talking bout the truck, or the explanation?
    2001 ECSB 4x4, 5.3, Radix, 3.0 pulley, VHP Trucker cam, 216/224 .551/.551 115 lsa, 1.8 Crane roller rockers, 4L65E, Yank SC3000, 3.73, Cal-Tracs, HPTuners.

  9. #9
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    Now that you mention the truck....I'll say both. The new sig pic is way better too....remember, I thought you had a dually looking at the older pic...

  10. #10
    blownwhite03 Guest

    Thumbs up im back

    so what your saying is that you open it up ,boost drops, power go up . Ive heard also each smaller pulley 20 hp . I gotta get aboost gauge. in theory I got your drift thanks. hey GG post somthing cool not c#$p thanks got it less restriction means less boost not less hp ;

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