Originally Posted by CarEXPERT
ChrisV, so you mean that the bigger and more powerfull the engine, a automatic would be good for drag racing?
A small engine requires a manual right ChrisV to be the best at racing?
generally, due to the fact that the smaller the engine, the higher it has to rev to make power, and automatics are gennerally not suitable for high rpm use (for example, teh modded AOD in my V8 RX7 was probably close to it's operational limits at teh 7500 rpm the 302 could rev to) Smaller engines also have narrower pwerbands, so they need more gear ratios to keep them in the optimum powerband, and automatics with enough gears are expensive and relatively heavy. Large engine cars don't need to rev as high, nor do they need as many gears to get the job done, so are not affected by the drawbacks teh automatic might have, and can take advantage of the performance advantages inherent in the automatic: faster shifts, mor power handling capability due to the design of the planetary gearsets, etc.
See a lot of what's happened in the sports car world in thinking manuals are more sporty is that in the early days, sports cars needed manuals to work right in road racing. Small engines had more power sucked out of them by the early autoamtics, which also overheated in racing use easier. But more importantly, small engine road race cars had VERY narrow powerbands. In order to keep the engine in the right powerband at any point on teh race track, the race builders needed to match the gearsets to the weight of the car, teh powerband of the engine, and the track itself (tight tracks needed more gears spaced closer together, longer tracks needed a bit wider spacing, and there were differneces for tracks with lots of elevation changes vs tracks that were fairly level). This meant that race teams would arrive at a track with multiple gearsets that they would swap out in practice to get the best combination. This is relatively easy to do in a manual gearbox using standard hypoid gearsets. But it's virtually impossible to do with the automatic box on site. Same for at-track repairs in an endurance race.
Often gearboxes were built by a few manufacturers (such as ZF, Getrag, Coletti, hewland, etc) and they could have one case and hundreds of gearsets available to match any concievable combination.
So, sports cars and road racing cars had manual transmissions for completly practical reasons. It had nothing to do with manuals being more fun, more sporty, or require more skill or give more control over the car in operation. But since sports cars had them, and sports cars were fun, the average person mistakenly equated the manual transmission as the REASON sports cars were sporty and fun.
Drag racers were concerned with getting to the end of the quarter mile quickest. Engine mods to make more power were and are very common. But the number of different kinds of cars isn't as great, only the level of prep. Torque rules them. And automatics handle more torque, and provide faster and more consistent shifts. With valve body mods to increase pressure, and higher friction bands and internal clutches, and torque converters that locked up or stalled properly, automatics transmitted as much power to the ground, shifted faster than you can manually, and allowed teh engine to continue to make power through the shift wihtout damaging the trans or risking a missed shift, as would happen powershifting a manual (where you hold the throttle to the floor while shifting as fast as you can). While heat buildup is still an issue, the cars aren't raced for hours at a stretch so overheting isn't as much of a problem. And multiple gearsets aren't an issue, as a drag strip is a straight stretch. Only differnce is traction and altitude. Any matching of gears and engine and car weight can easily be done with interchangeable final drive gears in the differntial, and fine tuned with tire diameter.
For STREET use, a mildly modded automatic is a perfect match to a powerful V6 or V8 engine, as it allows smooth commuting, and yet delivers full performance of the engine when you want it. In autocross, it meant one limb per control: steering wheel, shifter, brake, and throttle.
Like in this car: http://mywebpages.comcast.net/cvetters3/rex1.MPG