Supercharged/Turbocharged The increase in air/fuel pressure above atmospheric pressure in the intake system caused by the action of a supercharger or turbocharger attached to an engine.

3" charge pipe question

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Old May 23, 2005 | 07:07 PM
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3" charge pipe question

Does the 3" piping really help add that much more boost on the V2 supercharger. I have the pipes already i am just wondering if it is worth the hassle.
Old May 23, 2005 | 07:21 PM
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Without porting that TB or at least putting a Pathfinder TB on there, you are basically doing nothing but creating a lag from the moment you hit the pedal to when it actually gets into the TB/Intake, probably not noticeable, but not really worth it.

The small azz TB is the problem.

Dixit
Old May 24, 2005 | 04:11 AM
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Originally Posted by BigDogJonx
Without porting that TB or at least putting a Pathfinder TB on there, you are basically doing nothing but creating a lag from the moment you hit the pedal to when it actually gets into the TB/Intake, probably not noticeable, but not really worth it.

The small azz TB is the problem.

Dixit

good thats what i was wanting to hear . I didn't feel like messing with this really
Old May 24, 2005 | 09:23 AM
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Unless you are having issues with the pressurized pipe making the Z32 MAF run like cr*p when cold on the charged side. (w/ Z32 JWT Program)

Then it's possible the 3" intake pipe may help relieve the pressure some due to the larger diameter.

I'll be testing this theory soon.
Old May 24, 2005 | 10:00 AM
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I was just wanting to do it because i didn't know if it would help to produce more boost
Old May 24, 2005 | 10:50 AM
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I know - I just posted that as an FYI for people doing searches in the future.
Old May 24, 2005 | 11:56 AM
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I think it will create more power or at least make sure my car will run right with the Z32 MAF....Im in the process as well..ill post pics when its all complete next week sometime....

3" charge pipe Cromex Coated, all T-bolt Clamps, Silicone Couplers // 370's, Z32 MAF, and JWT-ECU all put in at once
Maybe down the road sometime, Ill put in a Pathfinder TB
Old May 24, 2005 | 02:01 PM
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I am not sure if anyone figured out if the pathfinder TB works on 5th gens? If they did then that would certaintly persuade me to do the 3" pipe.
Old May 26, 2005 | 09:48 PM
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but doesn`t a 3 inch charge pipe cause more lag?

i`ve actually seen a few aftermarket kit that came with 3 inch piping but is it really ness.ry? even 2.25 piping has made way more than 300 to 400 horse.
Old May 27, 2005 | 05:39 AM
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Originally Posted by chris'smax
I am not sure if anyone figured out if the pathfinder TB works on 5th gens? If they did then that would certaintly persuade me to do the 3" pipe.
What do you mean by "works"? I have a Pathfinder TB on my 00VI (sans IACV, though) and it works just fine.

If you are talking about idle control, the Pathfinder IACV is mounted on the bottom of the TB just like the A33 IACV. It might take a different harness connector, but I bet it could be made to work.
Old May 27, 2005 | 05:43 AM
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Originally Posted by Donald199
but doesn`t a 3 inch charge pipe cause more lag?

i`ve actually seen a few aftermarket kit that came with 3 inch piping but is it really ness.ry? even 2.25 piping has made way more than 300 to 400 horse.
Yes, but not enough to notice. I sure couldn't tell any difference.

Larger piping will result in lower pressure drop from blower to TB, especially at high flowrates. Small piping works fine with turbocharged setups because you can almost always increase boost to make up for intake system inefficiency. You can't (easily) do that with a supercharger though, especially if you already have a SC pulley that is putting you above the blower rpm limit. So piping losses become much more important.
Old May 27, 2005 | 06:18 AM
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Originally Posted by Stephen Max
Yes, but not enough to notice. I sure couldn't tell any difference.

Larger piping will result in lower pressure drop from blower to TB, especially at high flowrates. Small piping works fine with turbocharged setups because you can almost always increase boost to make up for intake system inefficiency. You can't (easily) do that with a supercharger though, especially if you already have a SC pulley that is putting you above the blower rpm limit. So piping losses become much more important.

So stephen in my case it would be a bad idea to switch to the 3" because i don't have a option for a larger throttle body correct?
Old May 27, 2005 | 06:45 AM
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Originally Posted by chris'smax
So stephen in my case it would be a bad idea to switch to the 3" because i don't have a option for a larger throttle body correct?
3" piping with a sudden drop in cross-section area (such as at a small TB) can result in more pressure drop than a constant cross-section system that is less than 3". So, yes, it is probably pointless to go to 3" piping unless you can also increase the TB size.

When designing an intake tract, you want to pay attention to the things that cause pressure drop:

1. Sudden change in air momentum. This can be due to both a change in velocity, such as encountering a change in cross-section, and a change in direction. Elbows and lower angle turns should be made with as large a turn radius as possible.

2. Turbulence in the air flow. Air flow transitions from laminar to turbulent at a certain Reynolds number, and the Reynolds number is heavily dependent on air velocity.

3. Pipe friction losses. This is also dependent on air velocity, as well as being dependent on the volume to surface ratio of the pipe. A larger pipe has a larger volume to surface ratio than a smaller pipe, therefore friction losses will be lower with larger pipes.

Friction losses are also increased by transitions from pipe to coupling. The change in cross-sectional area may be insignificant, but the sharp free edge of a pipe within a coupling will result in losses. The fewer the number of pipe pieces and couplings you use, the better, and cut edges of pipes should be chamfered and smoothed as much as possible.
Old May 27, 2005 | 06:51 AM
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Originally Posted by Stephen Max
3" piping with a sudden drop in cross-section area (such as at a small TB) can result in more pressure drop than a constant cross-section system that is less than 3". So, yes, it is probably pointless to go to 3" piping unless you can also increase the TB size.

When designing an intake tract, you want to pay attention to the things that cause pressure drop:

1. Sudden change in air momentum. This can be due to both a change in velocity, such as encountering a change in cross-section, and a change in direction. Elbows and lower angle turns should be made with as large a turn radius as possible.

2. Turbulence in the air flow. Air flow transitions from laminar to turbulent at a certain Reynolds number, and the Reynolds number is heavily dependent on air velocity.

3. Pipe friction losses. This is also dependent on air velocity, as well as being dependent on the volume to surface ratio of the pipe. A larger pipe has a larger volume to surface ratio than a smaller pipe, therefore friction losses will be lower with larger pipes.

Friction losses are also increased by transitions from pipe to coupling. The change in cross-sectional area may be insignificant, but the sharp free edge of a pipe within a coupling will result in losses. The fewer the number of pipe pieces and couplings you use, the better, and cut edges of pipes should be chamfered and smoothed as much as possible.

Thanks for the schooling
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