It Howls with small throttle bodies

[tom cloud]

>On Wed, 30 Oct 1996, Doug Robson wrote:
>
>> I installed an Autronic SMC computer and individual 50 mm throttle
>> bodies. Result 160-170 bhp  :(     ( sad face ).
>> I have recently had a set of 45 mmm bodies made with same diameter at
>> ram intake end but 45 at butterfly. result 205 bhp and more torque.
>> Drove it on track on Sunday and it howls. Im amazed at the difference of
>> 5mm makes. all other parts of the engine are unchanged since previous
>> set ( except bearings).
>
>I have an haltech E6 installed on my alfa. I used to run twin webers
>(36mm), but with the efi it is now running twin weber 45mm throttle
>bodies. I have to say that "takeoff" isnt that much fun (esp. up hills).
>It goes really well above about 3500rpm+, seems to get a lot of torque
>steer? as well if I hammer it.
>
>You wouldn't happen to know where I could get some chokes made up? I
>really want to choke them down to ~40mm, because this is the "Drive
>around" car (ie, I am not interested in the 2000rpm power band > 5000rpm).

Now I'm confused....  With my limited knowledge and cranial ability,
I thought that throttle size had little effect on FI.  I can see that
a larger TB gives less velocity and therefore less momentum and
mixture of the fuel/air, but can anyone 'splain to this ole boy
how to determine a TB size (talking normally aspirated).


Tom Cloud <cloud at peaches.ph.utexas.edu>