TheSamba.com :: View topic - Carburetor Airflow Comparisons for the VW.

Thu Nov 19, 2009 4:21 am

Tom Bruch has kindly tested, recorded and compiled this Airflow Comparison Chart for most of the commonly used carburettors for the VW.

Please make comments and ask questions as you see fit.

Thu Nov 19, 2009 6:37 am

huge thanks to tom for sharing this info.

Fri Nov 20, 2009 12:50 pm

Very nice information!

I don´t understand this with the 28PCI FVEE "blended top" what does that mean?

I can see the choke has been taken out also, is this the complete choke with axle and all?

I´m thinking about taking the choke out of the carb´s on my Express motor, they are not in use anyway!

Fri Nov 20, 2009 1:59 pm

its crazy how close the carbs flow are in stock form to the stock hp configuration. when calculating cfm into HP.
can tom or someone say something about how to use thes flow numbers?
i mean a stock 28 pci can also do to 50 hp on a judson engine...

Fri Nov 20, 2009 8:52 pm

Peter

On the F-vee the choke is completely removed, all and any rough edges anywhere are streamlined, the acc. pump nozzle area is narrowed & airfoiled, even the air corr jet is rounded and streamlined, the throttle shaft narrowed a lot & polished. Anything to make the carb interior have non-turbulent, laminar air flow helps. Removing the choke on an otherwise stock carb is barely noticeable in improvement. Its like do the bigest restriction first, like the weak link of a chain. Do the venturi first.

Sun Nov 22, 2009 10:47 am

awesome info on the chart! i have dual zeniths and its nice to see the difference between the modified version and the stock. however (and i cant seem to find the link) but theres a guy on the 356 registry who bored his zeniths out to a 36mm throttle bore and id love to see the comparison side by side. if i recall correctly the Solex P-II was still ahead in overall CFM but the pure velocity of the zenith was far superior to the solex.

Mon Nov 23, 2009 12:07 pm

bvilletom wrote: Peter

On the F-vee the choke is completely removed, all and any rough edges anywhere are streamlined, the acc. pump nozzle area is narrowed & airfoiled, even the air corr jet is rounded and streamlined, the throttle shaft narrowed a lot & polished. Anything to make the carb interior have non-turbulent, laminar air flow helps. Removing the choke on an otherwise stock carb is barely noticeable in improvement. Its like do the bigest restriction first, like the weak link of a chain. Do the venturi first.

Okay thank you, and I´m allready planning to get the venturi machined bigger.

Sun May 01, 2011 4:03 pm

Folks have been wanting me to do a flow comparison between the Wolfsburg West kit parts and the original Okrasa parts. I got the setups done & here are the figures. In a nutshell the carbs are not quite as good but the manifolds have way more potential.

Note: The replica intake manifold are larger everyplace which increases theair flow. However, they need some T.L.C. work in the runners to get it all.

All tested by Tom Bruch (Bville Tom) on a Superflow 110 @10 H20 (4-28-2011)

Sun May 01, 2011 10:11 pm

bvilletom wrote: Folks have been wanting me to do a flow comparison between the Wolfsburg West kit parts and the original Okrasa parts. I got the setups done & here are the figures. In a nutshell the carbs are not quite as good but the manifolds have way more potential.

Note: The replica intake manifold are larger everyplace which increases theair flow. However, they need some T.L.C. work in the runners to get it all.

All tested by Tom Bruch (Bville Tom) on a Superflow 110 @10 H20 (4-28-2011)

Thanx Tom for taking the time to test these new components and share this information with the rest of the 36 world. As a side note, while visiting with Wolfsburg West reps at the Bug In today I found out there are more 36hp perfromance components being developed. Stay tuned to Vintage Speed and the Wolfsburg West newsletter for more announcements over the next few months.

A huge thanx to Tony and the crew for making modern performance available to 36hp drivers.........................

Burly

Mon May 02, 2011 6:45 pm

bvilletom wrote: Folks have been wanting me to do a flow comparison between the Wolfsburg West kit parts and the original Okrasa parts. I got the setups done & here are the figures. In a nutshell the carbs are not quite as good but the manifolds have way more potential.

Note: The replica intake manifold are larger everyplace which increases theair flow. However, they need some T.L.C. work in the runners to get it all.

All tested by Tom Bruch (Bville Tom) on a Superflow 110 @10 H20 (4-28-2011)

Got my work cut out for me now Tom. Before I do any other changes to my engine I'll tune the carbs and intakes to see what improves.

Tue May 03, 2011 9:54 am

Thanks for sharing Tom!