First of all the simple answer:
No there is no limit.

First to address those people who follow the bigger orafice size is better law (hot rodder law #1).

A hole (orafice) will not flow any air at all without a pressure differential on each side of the orafice. For instance you either increase the relative pressure on one side, or lower the relative pressure on one side = bingo you have airflow. The rate of flow (known as CFM to hot-rodders) is primarily dependant on the difference in pressure on one side of the orafice VS the other side.
This means that you increase CFM by changing pressure. With a turbo/supercharger you can increase pressure on one side and increase CFM.
(note: this happens at the intake valve, NOT the throttle-body)

On the other hand, you can decrease the pressure in the chamber AND in the intake manifold by increasing the pull of the engine (vacuum producing capacity). The simple way to do this is simply increasing cubic inches.

CFM rating on carburetors etc. are based on 1.5 inches of mercury pressure drop (same as 0.7 psi below atmospheric pressure of 14.7psi or 29.93 inches of mercury). This means that an engine has to pull .7 psi at the throttle to flow enough air to equal the CFM rating of the carb or throttle body. This would leave about 14psi to feed the intake charge past the intake valve.

So does this mean that a little 500cfm two-barrel carburetor can flow over 1000cfm on the right engine?
ABSOLUTELY

The pull (vacuum) from the engine can be increased in several ways even without an increase in cubic inches. One of the biggest ways is through exhaust tuning or using the scavenging effect of headers to create a much much lower pressure in the chamber before the intake valve openning event.
Another way to increase pull is by changing the speed of the piston (other than RPM increase) at key points in the intake stroke cycle. The max piston speed is approximately midway on the piston stroke. Selection of crank-stroke and connecting rod length both affect the maximum piston speed. A faster piston speed will create more vacuum while the intake valve is open, and also create a stronger exhaust pulse for more scavenging effect. Valve events for intake & exhaust can be set to take advantage of this
(ie: Winston Cup).

A properly matched engine will put to shame your 330hp limit and silly calculations. Check out the real world.

Now for those that are screaming "hey wait a minute, that would increase CFM so the calculation is still correct"
Wrong again.

The amount of air and fuel consumed by an engine @WOT has no direct relation to power output at the crank or flywheel.

An example is in order.
Ok take your stock 305 and put in the junk long duration cam that lets a large percentage of air and fuel right out the exhaust due to excessive overlap. this means more air & fuel consumed but less power because less is burned in the chamber.

Another example,
This time two engines with identical camshafts and everything else except for the rods, crankshaft, and pistons. Even with equal cubic inches, the engine with the longer stroke would produce more power at the flywheel because of greatly increased mechanical leverage against the crank centerline.
The same amount of air & fuel can be burned in the chamber producing the same downward force on the piston, yet huge difference in power at the flywheel.
Leverage... check it out.

The engine that runs a longer connecting rod will also enjoy a leverage increase due to the rod/crank angle difference during the power stroke. Match this rod angle to your fuel burn rate to give you maximum cylinder pressure closer to the maximum leverage angle, and bingo = you have much more power.
one example: methanol burning engines.

Once again the stock TPI does not come into play because of any perceived reduction in CFM. By the way, what happened to Hot-Rod's calculation? they are physics experts aren't they?

Now as far as power to the rear wheels (the only thing that truly matters for performance), we have not even considered the increased leverage offered by the torque converter, transmission, or rear gears. It's starting to look like the TPI has little to do as far as limiting actual performance.

The TPI was a decent design in it's time that was shaped to produce good volumetric efficiency (& ramming effect) in the lower RPM range of the engine where a street car spends most of it's time. It works extremely well in the 3000-4000 RPM range where the shift recovery normally falls on a street car. A car that is set up to take advantage of this RPM range will perform great with a TPI.
The shape of a TPI will produce a curve in torque that peaks relatively low and falls off as RPM's climb. This torque fall-off is simply the characteristics of the TPI system and should not be viewed as any sort of limit.
A 400 cube engine will still have the potential to make more power with a stock TPI than a 305 cube engine (torque at a given RPM). Yes there are deminishing returns due to this fall-off at the higher RPM's. Even though torque at shift recovery is vastly more important to quick acceleration than horsepower at the top of the gear, it is very tempting to modify the stock TPI to reduce this high RPM fall-off.

Some people have limited success by simply upgrading induction parts to a larger size, but better results are achieved by changing their shape.
Shape is also a major factor on how many CFM's flow through an orafice of given size. A good induction shape will reduce the resistance to airflow and increase the velocity of the air.. thereby increasing CFM. This is a much better way of feeding an engine than simply openning up the orafice to a larger size which usually reduces velocity and can hurt CFM at certain RPM's in some cases.
A great example of improving orafice shape while maintaining it's approximate size:
Extrude Honing.

Even with CFM and leverage aside, there is still an even bigger factor to consider which also negates the theory of power limitation of a stock TPI. That factor is air density.
Even though you put a winston cup engine under the stock TPI you will reach some kind of limit on the dyno. This can be changed by modifying air density.
A big secret to getting the most from the TPI induction is the manipulation of air density. This is why it is so common for a well tuned TPI car to run 1/2 second faster in October than it did in July with only a difference in air density, and why an overly rich (the majority of cases) TPI car can gain up to a full second going from 90F degree air to 10F degree air. I have many many many vericom tests to back this up.

For you TPI owners. There are many tricks to increase air density in the TPI system, and if you look closely at the entire TPI you will see the factory has given you provisions that make this job easier.
Look in particular in the throttle-body and plenum areas.

hint #1 for runner ramming effect:
colder air is heavier with more momentum.

hint #2 for helmholtz effect:
pressure waves travel slower in denser air.


there goes your limitations. there goes your calculation. there goes Hot-Rod physics.

 

u should write a book.

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92' camaro
New 305 block TPI conversion, Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system.
Soon to come!!!
Procharger system 12lbs o boost.
Favorite quote: "where ever u go, there u are"

Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.

 

Hmmmmmmmmm something to think about...

 

So umm you gonna write something similar for TBI cars?

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

as you were told in the other reply, you should write a book. i'm moving to the tpi board where it should have more readers.

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ICON Motorsports

1st & 3rd