351 carbed problem

[George M. Dailey]

At 07:32 AM 10/2/96 -0500, you wrote:

>> For EFI stuff, the extra runner length and typical tiny throttle body
>>have more pressure drop than even a "small" carburetor.
>
>        [ snip s'more ]
>
>I'd like to hear some more 'bout this.  I bought the Holley Pro-Jection
>TBI and they say that unit has considerably less flow restriction
>than a comparable carb and that the requirement to size the cfm to
>the engine is relaxed for the EFI since the amount of fuel is
>determined by the electronics rather than vacuum and air flow.
>Is the above statement true for TPI and not TBI ??
>
>Tom
>
>Tom Cloud <cloud at peaches.ph.utexas>
>
>None of the opinions expressed here are mine or anyone elses
>
Let me step in and defend the ALL MIGHTY GM TPI. It's true that the TPI set
up does not flow 700 or 800cfm as the antiquated carbs do. But, with this
combination you simply don't need it, it gives 360ft-lbs of torque @ about
3,200rpm and one of the highest volumetric efficiencies of any normaly
asperated engine. One of the reasons the carbs were so big was because the
older engines had to be reved above 5 grand to get those high horse power
numbers the elders like to quote so much. With a wet intake manifold there
is a critical velocity to stay above to prevent a/f mixture seperation.
Don't forget, it's raw torque that makes the car go. Most (ALL) oem TPI set
ups are built to give you the maximum torque in region you need it most (low
rpm). Let me quote the last person I raced through the quarter (he had two
700cfm Holleys on a tunnel ram), "If we were racing accross the state, at
speeds above 130mph, I would have won .. you Son Of a ...!!" I couldn't hear
the last part due to my squalling tires.

GMD