Found this link and thought it was interesting.

http://www.charm.net/~mchaney/homedyno/dynokit.htm

I might just have to try this out. It uses RPM change over time calculations to calculated Torque/HP. This could be a cheap way to see differences before/after of performance mods to your car. Provided your accurate with the parameters required such as weight, gear ratio, temp, humidity etc.. Seems like it would be less accurate than G-Tech when comparing one car to another but more accurate in calculating actual performance differences before/after mods on a specific car where the basic parameters haven't changed. What do you think?

 

I've looked into it, but I don't like some of the assumptions that it makes. IMHO, it is more accurate to do something like this:

http://forums.audiworld.com/vag/msgs/457.phtml

 

Poor man's calculator:

http://www.tnmotorsports.com/dyno.htm

Just gotta go hit the 1/4 drags to get the numbers...

Anyone have the H.P. formula?

 

OK, just did a quick check and

hp = weight * speed * speed * speed / 12812904

where weight is in pounds
where speed is in Mile Per Hour

Horsepower is a measure of the force required to accelerate a weight to a known speed in a know distance.


Spinning your tires will lower your "effective" HP as well as bad shifts.

 

Awhile back, a gentleman by the name of Watt (the same gent who did all that neat stuff with steam engines) made some observations, and concluded that the average horse of the time could lift a 550 pound weight one foot in one second, thereby performing work at the rate of 550 foot pounds per second, or 33,000 foot pounds per minute, for an eight hour shift, more or less. He then published those observations, and stated that 33,000 foot pounds per minute of work was equivalent to the power of one horse, or, one horsepower.

ask.com: http://web.ask.com/redir?bpg=http%3a...;qte=0&o=0

Horsepower is the rate of doing work

Torque * RPM

Horsepower = ------------

5252

Same torque and increased rpm (incrreased rev limit = more power)

Torque is what moves you. However, if the redline is increased, you can avoid shifting and keep the torque multiplication of the lower gear.

 

How is this better (other than being cheaper but does less) than a Gtech Pro Competition?

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