[TheBoostCreep]

I would like to say that nobody knows for sure that the lower pulls were done in fourth gear. This seems to have been just a guess followed by consensus. With that in mind, and even if those plots were included in the set to be considered, the numbers quoted for the car would still be the peak number over a great many pulls.

The reason for discrepancies in power including the very low graphs could be many. The car may have experienced false or real knock conditions and pulled timing. The sensors which the Dyno uses for correction factors may have been misplaced or not set up yet. The conditions may have actually changed. I could go on for hours on the subject but let me just say that I am a dynamometer owner operator and a realistic pessimist.

Most chassis dynamometer shops do not provide more than three pulls for a baseline reading. This will lead to customers being all over the set you see here. People will be upset and others will be happy. The happy people will probably post their numbers and further reinforce the idea that all of these cars should make one hundred seventy wheel horsepower. The low reading cars may have even had it in them to generate higher numbers if given the chance to do as many pulls as what you see here.

None of this matters because Dynamometer readings truly are just to make changes and see the results. Accuracy and precision are the two classic factors here which seem to cause endless online debate. What this means is that we can never know for sure how cars stack up against each other on different days and in different places, but it means that we can know when we've made an improvement to a car in a controlled environment.

I have a little story I have come up with to explain the importance of horsepower and torque. Hopefully it will make the concepts clearer and illuminate the importance of both.

One day the two twin brothers Romulus and Remus decided to have a race in their little radio Flyer wagons. For purposes of this conversation they weigh the same, so do the wagons, and the radius of the wagon wheel and tire is exactly 1 foot. These boys enlist the help of the neighborhood kids and the challenge is set forth. Only one tire may have force applied to it, for they are new, made of alloy,and very nice.

Romulus believes that more torque is always better so he enlist the help of a kid who is carrying a 10 pound sledgehammer. Due to safety concerns everyone else must stand clear when this boy imparts his force to the tire by hitting it at an approximately tangent line on the tire. Because of the weight of the hammer, he is only capable of swinging the hammer once per second against the tire. This mathematically gives us a torque reading/polar moment of 10 pounds per foot. Romulus is very impressed with this performance and get sucked back to the back of the wagon with each hit. He is very pleased. Grass is flying!

Remus loves science, and he is very much into drag-racing. So he decides to enlist the help of four neighborhood children. He hands them out a set of croquet mallets which are much lighter than the sledge hammer. With the much lighter mallets, the children are capable of standing in line and taking turns. Each child imparts a 6 pound force to the tire and can do so in half of one second and then get out of the way for the next child. While perfecting this technique in the back lawn of his parents house, Remus starts to doubt his wisdom, he doesn't feel like he is getting pulled back as hard as he can see his brother is, and he senses that his brother is feeling more acceleration. But they have the timing down and every half second he gets another pulse, although a small one.

Finally, they lined up to race. After two seconds Remus, although he's not getting pulled to the back of his cart, is starting to leave Romulus behind. Romulus is feeling the pull as his sledgehammer powered wagon sets him back to the back with every hit. But he is losing the race.

The reason for the discrepancy between what the two boys feel and what they experience is the difference between horsepower and torque. By taking time into account we are able to quantify and study the effects of our decisions, and predict the results of this race. This is in spite of what our Butt Dyno would tell us about the situation. And this is why chassis dynamometers are so wonderful.

After two seconds in the race, mathematically, in Remus's case, the four hits from the neighborhood children have imparted a moment sum of 24 pound feet to the wagon which Remus rides. Romulus has only seen 20 pound feet in terms of an additive of moments over the same two seconds. This is the crux of the difference between horsepower and torque. Horsepower and torque truly are mathematically linked.

Horsepower equals torque multiplied by the rpm divided by 5252. This is what makes a turbocharged Honda quick and fast but not incredibly torquey, and also why turbo diesel trucks feels so damn good. It is also why they are useful, for later that afternoon in the sandbox the results were different.

Hopefully my drivel is worthy of your readership, and now back to our regularly scheduled debate.

Thank you James Watt!