3.09 gear set with 3.23's
and elevation.
It's really hard to beat a properly working Torque convertor for off-the-line jump.
Every TC has a an internal torque-multiplying feature that at stall may be as high a 1.8 to 1. And this automatically diminishes to in the neighborhood of 1.1 with speed and rpm.
So on the starting line,in first gear at zero mph,and at WOT, the 3.23s could behave like 5.81s. A few feet out the ratio is automatically reducing towards say 1.5 at peak torque and maybe 1.3 at shift rpm. It's like having an automatic planetary super low gear.
Below is a snapshot of what your engine's power curve MIGHT look like. That build sorta mirrors mine, except I have OOTB Eddie heads and ~180 psi pressure.
Ok so with 3.23s and a 2.45 low gear, out of the gate, it will feel like
3.23 x 2.45 x 1.8=14.25... whereas the 2.33 4-speed will feel like
3.23 x 2.33 =7.53
Ok so say you have a 3000 stall; look on the graph and find the power at 3000, I get 210hp; which is 367 ftlbs torque. Multiplying that by 14.25, you get 5237 available ftlbs on the start line
To get that from the 4-gear, you would need
5237/7.53= 695 ftlbs which is impossible for this engine to generate.
Lets move to the torque peak, I'll go with 4800rpm.
So if your TC ratio is 1.5 then
437 x 1.5 x 2.45 x 3.23=5190 ftlbs available, and the 2.66 still can't touch it. This is why the factory almost always gave the 340 4-gear cars more rear gear. Let's try 3.55s
437 x 2.66 x 3.55=4127 still no contest. Lets try the 3.09 low
437 x 3.09 x 3.55=4794 getting there.
Let go to peak power, say 5700rpm and 437hp =400 ftlbs.
with the automatic;
400 x 1.30 x 2.45 x 3.23= 4115 ftlbs available. and the 4-gear is
400 x 2.66 x 3.23= 3437, while the 3.09 is
400 x 3.09 x 3.23= 3992, closing the gap. And with 3.55s
400 x 3.09 x 3.55= 4388 badaboom!
Like I said, in first gear, combo for combo, it's really hard to out accelerate an automatic. The auto will be way out in front, even with the 3.09 x 3.55, until after the torquepeak has flown by.
I have an engine combo similar to yours, and I do have the 3.09 x 3.55 combo. I don't really need the 3.55s, but they work well with my GVod. If I didn't already have it, I would put the 3.23s back in.
So that leads to the final question; What's wrong with either; your combo, your stall, or your TC itself.
What is your actual cranking cylinder pressure ,
and elevation.
It's really hard to beat a properly working Torque convertor for off-the-line jump.
Every TC has a an internal torque-multiplying feature that at stall may be as high a 1.8 to 1. And this automatically diminishes to in the neighborhood of 1.1 with speed and rpm.
So on the starting line,in first gear at zero mph,and at WOT, the 3.23s could behave like 5.81s. A few feet out the ratio is automatically reducing towards say 1.5 at peak torque and maybe 1.3 at shift rpm. It's like having an automatic planetary super low gear.
Below is a snapshot of what your engine's power curve MIGHT look like. That build sorta mirrors mine, except I have OOTB Eddie heads and ~180 psi pressure.
Ok so with 3.23s and a 2.45 low gear, out of the gate, it will feel like
3.23 x 2.45 x 1.8=14.25... whereas the 2.33 4-speed will feel like
3.23 x 2.33 =7.53
Ok so say you have a 3000 stall; look on the graph and find the power at 3000, I get 210hp; which is 367 ftlbs torque. Multiplying that by 14.25, you get 5237 available ftlbs on the start line
To get that from the 4-gear, you would need
5237/7.53= 695 ftlbs which is impossible for this engine to generate.
Lets move to the torque peak, I'll go with 4800rpm.
So if your TC ratio is 1.5 then
437 x 1.5 x 2.45 x 3.23=5190 ftlbs available, and the 2.66 still can't touch it. This is why the factory almost always gave the 340 4-gear cars more rear gear. Let's try 3.55s
437 x 2.66 x 3.55=4127 still no contest. Lets try the 3.09 low
437 x 3.09 x 3.55=4794 getting there.
Let go to peak power, say 5700rpm and 437hp =400 ftlbs.
with the automatic;
400 x 1.30 x 2.45 x 3.23= 4115 ftlbs available. and the 4-gear is
400 x 2.66 x 3.23= 3437, while the 3.09 is
400 x 3.09 x 3.23= 3992, closing the gap. And with 3.55s
400 x 3.09 x 3.55= 4388 badaboom!
Like I said, in first gear, combo for combo, it's really hard to out accelerate an automatic. The auto will be way out in front, even with the 3.09 x 3.55, until after the torquepeak has flown by.
I have an engine combo similar to yours, and I do have the 3.09 x 3.55 combo. I don't really need the 3.55s, but they work well with my GVod. If I didn't already have it, I would put the 3.23s back in.
So that leads to the final question; What's wrong with either; your combo, your stall, or your TC itself.