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Old 08-09-2005, 02:27 PM   #1
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Default Why 3" pipein for intake mod on Boost?

Just thinkin out loud.. I can understand air velocity for N/A cars, thats why 3" maybe needed.

But wouldn't boosted car be different? I was thinkin of going with 4" ID pipeing ( whenever I get my other project done first ) since the velocity will still speed up when it gets compressed going into the TB opening.. the ID of the TB is bigger then 3" its somethin like just under 3.5" or something like that ( as I can fit a whole 3" ID filter opening into the TB on my car..

A smaller pipe would then reduce the amount of air being SUCKED into the TB then wouldn't it.. even though the Velocity maybe different
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Old 08-09-2005, 02:41 PM   #2
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3" is usually used cause thats the size of the throttle body (well close). 4" would be less restrictive and better for sc applications but you would need a 4 to 3" reducer and the 4" is tougher to route and make work?
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Old 08-09-2005, 02:41 PM   #3
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You have to look at the big picture with fluid dynamics. ADTR actually test 2.5", 3", and 3.5" pipes. The conclusions backed up my theory.

1. 2.5" is sufficient for flow on an L27 and an L36. Laminar flow is more important for these cars than supercharged, but laminar flow is more efficient in the high-flow demands of an L67.

2. The larger the pipe, the less laminar flow you get. Velocity helps with the laminar flow, and allows you to move the air more efficiently in the right direction.

3. A 4" pipe will NOT be as laminar as a 3", and based on flow calculations of the M90 and M62 at typical performance pulley sizes we run, none of us can outlflow a 3" pipe.
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Old 08-09-2005, 03:03 PM   #4
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Ahh.. thanx guys with them bling bling stars
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Old 08-10-2005, 12:48 PM   #5
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Not to add more to the ever constant discussion of intake pipes, BUT ......

http://www.weapon-r.com/store/agora....&ppinc=search2

They claim things like higher volume, laminar flow, venturi effect, etc ....

Any experts care to share their thoughts? Could one of these 3.5" pipes be beneficial on a L67 or am I just wishing and should stick with the AutoZone ricer pipe?
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Old 08-10-2005, 01:27 PM   #6
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Quote:
Originally Posted by griff1455
Not to add more to the ever constant discussion of intake pipes, BUT ......

http://www.weapon-r.com/store/agora....&ppinc=search2

They claim things like higher volume, laminar flow, venturi effect, etc ....

Any experts care to share their thoughts? Could one of these 3.5" pipes be beneficial on a L67 or am I just wishing and should stick with the AutoZone ricer pipe?
They went with a 3.5" pipe to gain back the cross-sectional area the lost by adding the inner pipe and standoffs. The concept works, the inner pipe isn't used to increase velocity DIRECTLY but that would be the end effect. The inner pipe/outerpipe arrangement improves laminar flow characteristics, which in turn increase velocity.

I doubt any cars shown on that site or their customers could outflow a 3" pipe if we can't with our L67'* that are pulley'd. Do the math on the cost of that intake, and I doubt the extra $$$$ is worth the unclaimed horsepower increase in that article.

In simpler terms, if a Honda can't outflow a 3" pipe to begin with, what'* the friggin' point in doing this? Bragging rights. Nothing more.


Quote:
AIR FILTER / COUPLERS / HOSES ALL SOLD SEPERATELY.

Made of 6061 Aluminum
Mendrel Bent
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Made to your spec'*

Charges:
Per Bend: $40
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8mm Nipple Welded: Add $22
10mm Nipple Welded: Add $23
15mm Nipple Welded: Add $25
1" Nipple Welded: Add $30

Per Aluminum Air Flow Sensor:
Subaru Air Flow Sensor Welded: Add $40 ( SENSOR 2 )
Nissan Air Flow Sensor Welded: Add $40 ( SENSOR 3 )
Ford Air Flow Sensor Welded: Add $40 ( SENSOR 3 )
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Toyota Triangle Air Flow Sensor Welded: Add $40 ( SENSOR 2 )

Polishing:
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Convert custom intake to Secret Weapon Configuration:
Add: $90

Please include 6 good pictures ( Multiangle ) with an measuring tape next to the OEM intake pipe.
Drawing of your desired configuration.
Size and location of nipple(*).
Type and Location of Sensor. ( If applicable )
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Old 08-10-2005, 01:40 PM   #7
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Ya know, I had this little voice in the back of my head saying "willwren is gonna say ....." and I was thinking it myself, I just had to have somebody tell me!

They quoted me an estimate of $225, my measurements, and no garrauntee of fit. If the gains would be worth it, I would jump, but I think that $225 will be best invested elswhere.
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