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Why does removing restrictor plate provide more boost but headers decrease boost?

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Old 07-31-2018, 08:06 PM
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badass1g
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Default Why does removing restrictor plate provide more boost but headers decrease boost?

I do not understand this theory. Shouldn't all things improving airflow increase your boost level? Such as an intake, exhaust, restrictor plate removal. Yet it seems that doing headers lowers boost levels? If someone was running around 600 hp on a supercharged C7, and they added headers. How much boost would they lose from the additional airflow?

Would they gain HP still even if they didn't pulley down or would the decrease in boost rob the new power from the headers?
Old 07-31-2018, 08:13 PM
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BrunoTheMellow
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Boost is pressure... Flowrate is what increases power. That's the CFM rating you see on the data sheets. Pulling the restrictor plate allows a bigger hole for air to go in. Putting long tubes allows a bigger hole for air to go out. Therefore more air flows through. More power.

Think about a garden hose. You open the tap to get more pressure, then you squeeze the end to keep the water pressurized. When you let go of the end, more water flows because you're restricting it less.

Last edited by BrunoTheMellow; 07-31-2018 at 08:14 PM.
Old 08-01-2018, 09:55 AM
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JHEBERT
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Exactly, but some people think lower boost equals less power. In fact, you could run at 19psi on a stock engine, then with heads/cam on the same combo make only 14lbs but still make over 100hp more. The engine (air pump) has become less restrictive to the blower, enabling more air/fuel through it.

Last edited by JHEBERT; 08-01-2018 at 09:55 AM.
Old 08-02-2018, 08:49 PM
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3 Z06ZR1
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I heard that but my results show more boost graphed
. Only change here was a new set of 2 inch headers w/tune. Gained boost and hp!
Not saying a cam does though they typically will show less boost but more power.

Last edited by 3 Z06ZR1; 08-02-2018 at 08:53 PM.
Old 08-06-2018, 08:45 PM
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Old 08-06-2018, 09:51 PM
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AZGASSER
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Originally Posted by BrunoTheMellow
Boost is pressure... Flowrate is what increases power. That's the CFM rating you see on the data sheets. Pulling the restrictor plate allows a bigger hole for air to go in. Putting long tubes allows a bigger hole for air to go out. Therefore more air flows through. More power.

Think about a garden hose. You open the tap to get more pressure, then you squeeze the end to keep the water pressurized. When you let go of the end, more water flows because you're restricting it less.
That is the best analogy out there. I am in medicine and teach young docs that pressure does not equal flow. We get fixated on boost but that is just a measure of back pressure of a system. The simple way to make more energy is more air in and more air out. The engine is just an air pump fueled by compressed gas.
Old 08-06-2018, 10:00 PM
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Originally Posted by 3 Z06ZR1
I heard that but my results show more boost graphed
. Only change here was a new set of 2 inch headers w/tune. Gained boost and hp!
Not saying a cam does though they typically will show less boost but more power.
Looking at the graph it looks like your boost was essentially unchanged from the header swap but your HP/TQ increased. This goes to show that you reduced back pressure and increased flow and increased HP/TQ. When you start down the mod path, you will find the next area of flow restriction with each changed. Remembering your posts, you opened inflow with the Haltech, then got the air out with better headers. Now increased the forced air in with the 2300. Curious to know what your boost change was between the two blowers.
Old 08-08-2018, 10:23 PM
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Originally Posted by AZGASSER
Looking at the graph it looks like your boost was essentially unchanged from the header swap but your HP/TQ increased. This goes to show that you reduced back pressure and increased flow and increased HP/TQ. When you start down the mod path, you will find the next area of flow restriction with each changed. Remembering your posts, you opened inflow with the Haltech, then got the air out with better headers. Now increased the forced air in with the 2300. Curious to know what your boost change was between the two blowers.
Max boost before and after the headers shows an .4 psi increase. The 2300 is shown here same dyno. I'm no rookie at this 11 years ago I put an A&A and headers on a Ls3 C6. Discovered larger headers flowed better for me.
The number is hard to see but it made 12.98 psi about 1.2 psi more 2300 to 1.7 spinning slower.

Last edited by 3 Z06ZR1; 08-08-2018 at 10:27 PM.
Old 08-08-2018, 10:43 PM
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AZGASSER
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Dude, even when someone agrees with you are a tool. The dyno graphs you show like the one above is absolute garbage. Get a scanner and a clean pic then talk. There is no scale for A/F or boost seen on there. Put that on the original graph then talk numbers that add to the conversation. I wish you could understand how to be a productive person on this forum instead of a condescending @#$#^. You are a small man with a small IQ.
Old 08-14-2018, 07:52 PM
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56985]Dude, even when someone agrees with you are a tool. The dyno graphs you show like the one above is absolute garbage. Get a scanner and a clean pic then talk. There is no scale for A/F or boost seen on there. Put that on the original graph then talk numbers that add to the conversation. I wish you could understand how to be a productive person on this forum instead of a condescending @#$#^. You are a small man with a small IQ.[/QUOTE]

What a jack *** and a tool! I just told you the difference so you get mad!
The scale is there the graph is there. The max boost is what you asked and it is there you are just too dumb to read it!
What a whimpy man you are!

Last edited by 3 Z06ZR1; 08-14-2018 at 10:51 PM.

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