A&Q about 350Z
Q:
Yes and no, maybe, one perhaps and a yeah.
Horsepower is a useful measurement, however it has come to be associated with the wrong parameter of a vehicle's performance. Its like the light bulb analogy. A 100w light bulb is something we understand and we assume that one brand of 100w light bulb will put out the same light as the next, but most people couldn't tell you how many amps it draws or why. They just accept "100w" as gospel truth. In truth, the actual number of lumens (and what color they are) are very different between brands and affect the actual light you get. Horsepower is very similar. The general public hears "150 hp" and assume that it is an indicator of how much "light" they'll get. In truth, they're all different colors and lumens.
If people could really understand the HP/TQ relationship they would see how (although hp is a valuable number) the shape and contour of the torque curve is the real tell tale line. On desktop dyno, I don't even have the simulator plot the HP curve anymore; I have it plot IMEP, BMEP, or VE. When I look at a torque cuve I can guess where the HP is since its just a matematical derivation.
True, however, those numbers are based on the ENGINE's RPM. If have a 2:1 first gear ratio, you've now doubled the torque, but halved the RPMs. If you plotted the corrected RPMs to reflect OUTPUT SHAFT RPM on a graph, it would look the same as the original. This is the main reason that chassis dynos are tested with the tranny in what ever gear is 1:1 or closest. Its corrected for a generic rear axle ratio and tire size, but the difference is minimal. Having said that, if you tested your car on a chassis dyno with 3.42 gears, then retested the same car after a 4.10 swap, the curves would be slightly shifted.
You are correct with using gear ratios to make things look good at the output shaft, but they would drive very differently. If you took a high-strung race engine and geared it way down to get the torque multiplied enough at low RPMs, you would have several problems (and these are very fine points, but applicable nonetheless) First, the gearing would have to be very close for the race engine's narrow torque curve peak. Second, you would have to have 15-20 gears to get your top speed RPM below 40,000
Third, although the lower gearing would be beneficial to improve the torque on the low end, race engines make tons of torque... way up high in the band. That gearing you chose to make stump pulling torque would let the engine spin through its effective torque band way too fast.
Multiplying the torque isn't as important as keeping the engine in its most effective powerband for the greatest amount of time. If I have time later I'll post some graphs of dyno charts with some gearing options and you'll see that the gearing and engine have to be matched or else it just won't be a useable machine.
Good counter point
A:
Curtis is right, many people just talk horsepower btu more important is the shape of the torque curve and where it is in the rpm band.
One thing to add though. On a dyno, torque is usualy measured and horsepower then calculated. On what most of us usually see on a chassis dyno is called an inertia run, where the gigantic drum underneath the floor is accelerated and the computer calculates rate of acceleration and the weight of the drum and some other junk to come up with a hp number the plugs that into the hp-tq formula and comes up with torque. So on an engie dyno when you don't use a transmission, you are actually measureing torque and calculating horsepower. On a Chassis Dyno doing an inertia run, you are calculating hp and then calculating torque, the computer will get the rpm figures from the engine (plug wire) so everything is calculated. So there is no way to fool hp/tq numbers through gearing in the normal chassis dyno inertia run.
A:
Legionofone, How about stock-block and commercially available fuel as regulators? In that case, you should look into pulling tractors. Lots of I-6's there.