Thoughts on throttle bodies

Michael Gough mdg3369 at
Sun Feb 10 08:10:23 EST 2002

> So if the Audi TB is truly 38/52mm then according to my calculations...
> It should have an effective area of 64.4mm so even if the other TBs would
> fit - it still wouldn't make much difference, except in the way the car
> drives when you are off the throttle.  Seems the VR6 motor from VW uses a
> 65mm body as well?
> Just some musings...

Yes this is correct. Even using a "larger" (65mm) round TB is a waste of
time. I did the calculations one day, and though to myself, "Hey this thing
(the double butterfly progressive) is BIG" I also prefer the progressive
style TB to the round ones for ease modulation, not on-and-off like some.
In my EFI conversion I am going to be using the naturally aspirated intake
manifold (to clear the fuel rail) and the Digifant Fox throttle body which
is the exact TB as the N/A 5 cylinder, but it has a TPS sensor built in.
Swap the throttle body and I'm done! No worries about rigging up a TPS
sensor, or fuel rail clearance issues.

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