All dyno curves are at WOT.
Streeters are almost never at wot, unless the cam is just way too big; then they use up all their available throttle just to struggle off the line.
So you hear about the guy who bolts on a 340 top end and cam onto his 318 engine and he says it ain't so bad. What he doesn't tell you about, is the 3000 stall and 3.91s he's running, so he's never in that gutless sub-3000 rpm zone, to start with, and if his engine is lazy, the 3.91s don't squawk about it.
But put that same engine in front of a regular A833 with 3.55s, and suddenly she's a turd below 25 mph and it lays over on every "normal shift" on the primaries, just to to keep accelerating, at a reasonable rate.
This engine will respond completely differently with a matching to the 340 cam, boost in cylinder pressure.
Another thing you need to always keep in mind is that lo-compression engines cannot draw the cylinder pressure down sufficiently low enough,on the intake stroke, for atmospheric pressure to want to be eager to dive in there. And then with a long period cam, at low-rpm, the piston starts pushing some of the meager amount of air it got, back up into the intake. and the bottom-end torque takes a dive. Adding compression ratio at this point is a real game-changer. The air now being eager to get in there builds a good head of steam, and only the tail end gets pinched off as the piston charges up the cylinder.
To be sure, for a streeter, it's a somewhat delicate balancing act. But if your combo includes a manual trans and hiway gears, and lots of city mileage, it is well-worth it to crank the pressure as hi as you dare, with a small engine. The 360 will make more low-rpm torque inherently, and is less sensitive to the pressure loss at low rpm. And it usually makes more than the chassis can handle anyway. You hardly ever hear a guy come on FABO complaining about how gutless his 360 is off the line. But every 318 owner out there, has this as their number one frustration.And they all want to cam it bigger. and they all want to not put pistons in it. And they all don't understand that you can't make a silk-purse out of a sow's ear.
But I digress.
Max VE usually occurs with peak torque, which usually occurs close to 1500 rpm under the power peak. So if your cam peaks at 5000, then your peak torque might come in at 3500. And that means from 3500 back to the stall-rpm, VE is dropping off. And without changing the cam, just about the only way to get the torque up down there, is with more cylinder pressure.
So hang on where is 3500?
In first gear with 3.55s and 27s, 3500@zero-slip =32 mph.
Is this gonna be a problem? Well maybe yes and maybe no. If you have a 360 it will have plenty of torque to not require WOT, to accelerate briskly. But if you have a smaller engine, it might require WOT to keep up to that 360.
What about second gear?
32 mph is 2050 at light throttle/zero-slip. So with a 3000 stall TC no problem. But with a 2000, you are going no where fast with a lo-compression, small displacement engine. So it will have to back-shift to get moving.
So where is 3500 in second gear? That would be 55 mph.
If you take first gear to 5000, then the Rs will drop to 2950 in second. And there is your engine struggling again, from 51mph at WOT all the way to 55mph before it starts marching up the horsepower curve. So,if you don't want your engine to be struggling from 51/2950 to 55/3500, you are gonna need more cylinder pressure, or a high-stall TC.
OK so lets look at it another way; when is the lo-compression engine actually alive? Answer; from 32 to 38 mph in first gear, and from 55 to 60 and beyond to 71 mph. Then comes the 2-3 shift.
So there you go; the low compression engine from zero to 60mph,by the numbers is doing ok for 11 mph, the rest of the time it varies from lazy-dog to lazy pony....... unless you put a hi-stall on it. Which doesn't actually take the laziness away, it just lets the engine not be in the lazy-zone, at take-off, ...... but doesn't solve the problem in second gear, until the stall is something like 3500.
But the thing I want to stress is all the above is happening at WOT. In the real-world I'm gonna guess that 95% or more of the time, my engine is at sub 3000 (2800 even). And the reason is because with 180psi,and being a 360 it makes mountains of low rpm, Part-Throttle torque, and with 355s she doesn't need any more rpm to accelerate briskly.In fact, the 230* cam in it today is a compromise to reduce the cylinder pressure, simply because I did not know that I could run higher than 180psi. I thought I was already pushing it. then I come to FABO and hear about some of you pushing 200 and more, still on pumpgas.So if this 230* cam ever dies,then I will likely back up a size or maybe two even, and let the pressure climb close to or into the 190s.
It's like Rusty said; his low-compression 400 is gonna be fun strictly because it has the cubes. It doesn't need the pressure nor even want it; because the surplus will just go to heat, mechanical trouble, or tirespin.
Really, IMO, its the 318s and smaller that need to run on the edge. That might include the lo-C 340s