Velocity Stacks for Weber 40 IDF's |
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Velocity Stacks for Weber 40 IDF's |
NJ914Guy |
Mar 12 2011, 07:36 AM
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#1
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Member Group: Members Posts: 150 Joined: 30-December 10 From: Deptford, NJ Member No.: 12,546 Region Association: MidAtlantic Region |
My kit came with the Weber/Redline air filters but no velocity stacks. Does anyone have a good source for 40 IDF velocity stacks which will fit inside of the air filters? Will adding a short (est. 2" stack) inside the filter element make a real difference?
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nsr-jamie |
Mar 12 2011, 07:52 AM
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#2
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914 guy in Japan Group: Members Posts: 1,182 Joined: 7-November 07 From: Nagoya, Japan Member No.: 8,305 Region Association: None |
My kit came with the Weber/Redline air filters but no velocity stacks. Does anyone have a good source for 40 IDF velocity stacks which will fit inside of the air filters? Will adding a short (est. 2" stack) inside the filter element make a real difference? CB performance |
mrbubblehead |
Mar 12 2011, 10:14 AM
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#3
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Twodollardoug Group: Members Posts: 1,155 Joined: 17-December 10 From: calimesa ca. Member No.: 12,492 Region Association: Southern California |
aircooled.net
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NJ914Guy |
Mar 12 2011, 10:22 AM
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#4
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Member Group: Members Posts: 150 Joined: 30-December 10 From: Deptford, NJ Member No.: 12,546 Region Association: MidAtlantic Region |
Thank you for the recommended vendors. Do you believe that the stacks will add performance/increased drivability to the car?
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Jeffs9146 |
Mar 12 2011, 10:40 AM
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#5
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Ski Bum Group: Members Posts: 4,062 Joined: 10-January 03 From: Discovery Bay, Ca Member No.: 128 |
There was a thread a few years back that did a test on a dyno testing what affect changing the VS made to top end and bottom end power! I don't remember what the final out come was but it did make for an interesting read!!
Found it!! (IMG:style_emoticons/default/piratenanner.gif) Velocity Stack Testing by Jake I just took a closer look at the thread and it looks like the graph and photo links are no good any more! Maybe Jake could update his results here? (IMG:style_emoticons/default/aktion035.gif) |
URY914 |
Mar 12 2011, 11:50 AM
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#6
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I built the lightest 914 in the history of mankind. Group: Members Posts: 120,614 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
CB Performance are crooks when it comes to shipping costs. I'd go with aircooled.net.
You must have v.s. on the carbs. |
ripper911 |
Mar 13 2011, 07:36 AM
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#7
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corde pulsum tangite Group: Members Posts: 2,920 Joined: 25-April 10 From: Powder Springs, GA Member No.: 11,654 Region Association: South East States |
My set from redline is also Velocity stackless, how vital are they?
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J P Stein |
Mar 13 2011, 08:59 AM
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#8
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
I bought some from a local VW bug shop. A 0 on the hassle scale.
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jmill |
Mar 13 2011, 09:30 AM
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#9
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Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
My set from redline is also Velocity stackless, how vital are they? The air entering the carb is quite turbulent. Stacks smooth out the flow which results in an increase in velocity. More velocity = a denser air fuel mixture. Think forced induction on the cheap (it's no turbo or blower but it helps). It also cleans up the vacuum signal to the mains. They aren't vital but you will have some gains up top. |
ripper911 |
Mar 13 2011, 09:50 AM
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#10
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corde pulsum tangite Group: Members Posts: 2,920 Joined: 25-April 10 From: Powder Springs, GA Member No.: 11,654 Region Association: South East States |
off to the VW shop when I get a chance then!
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J P Stein |
Mar 13 2011, 10:36 AM
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#11
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
Tell these guys they are not "vital" or that lenght is not important.
Attached thumbnail(s) |
jmill |
Mar 13 2011, 10:53 AM
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#12
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Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
Apples and oranges. In a race car, where a few HP makes all the difference, they are "vital" to winning. Parked in my driveway that would be a squirrels wet dream. An aircleaner is more "vital" than a mm of stack height in a street car.
Tell these guys they are not "vital" or that lenght is not important. |
r_towle |
Mar 13 2011, 11:06 AM
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#13
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
with 40 IDF carbs on a slow velocity type 4 head, the short (1/2 inch tall) velocity stack that is built into the air cleaner base seems to be the right setup. Jake did quite a bit of testing on the proper heights to use and it certainly has alot to do with the camshaft and head setup you are running. Anything close to stock (heads, valves or camshaft) will actually experience a loss of power in the lower RPM range if the taller stacks are installed. As you add height (on the type4 motor) it moves the HP up in the rpm range and this is a high torque motor down low. Hard question to answer without knowing your specific setup and your intended use of the car. Rich |
gothspeed |
Mar 13 2011, 09:08 PM
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#14
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
There was a thread a few years back that did a test on a dyno testing what affect changing the VS made to top end and bottom end power! I don't remember what the final out come was but it did make for an interesting read!! Found it!! (IMG:style_emoticons/default/piratenanner.gif) Velocity Stack Testing by Jake I just took a closer look at the thread and it looks like the graph and photo links are no good any more! Maybe Jake could update his results here? (IMG:style_emoticons/default/aktion035.gif) +1 .......... I like graphs of 'real life' tests ........ (IMG:style_emoticons/default/smile.gif) |
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