EvoTillIDie

iTrader: (1)

Hey everyone I was looking at some of the dyno charts on here & with a little bit of common sense I could understand it. But I want a full understanding of it. So I was wondering if any expert on here would be able to help me learn how to read them? A VIDEO would be extremely helpful. Thanks in advance !

ampire

iTrader: (12)

A dyno chart shows the amount of power and the amount of work an engine generates at a given rate of revolutions per minute.


Horsepower is a function of torque over time (power = work/time). Horsepower = Torque (lb/ft) * RPM / 5252.
In this case 5252 is a constant approximating 1 lb/ft of torque in 1 minute. Therefore on a dyno chart, horsepower and torque curves must always cross at 5252.

The vertical axis is the amount of torque or the amount of horsepower (sometimes shown on same side or torque on one side horsepower on the other) and the horizontal axis is the engine RPM.

Peak power and torque are the highest numbers each curve will reach. However its not all about the peak power.

ranmas2004

iTrader: (2)

This^

I'm no expert but I've learned something on the way. Here is my graph before and after 17 degree timing advance on 2002 Maxima.

Mods: Cattman Headers, y-pipe, 3" exhaust, Stillen UD Pulley, NWP Spacers (5 piece), Custom Short Ram Intake, Spec Stage 2 Clutch, Fidanza flywheel......



Although peak numbers are about the same......the are area under the previous curve is pretty big. THIS TOTALLY changed the car and the way it drives now!!! So much more torque and power. So peak numbers not everything.......

Hope this helps....

EvoTillIDie

iTrader: (1)

Thanks, it really does, another question, so when doing a dyno I'm guessing you rev the engine out all the way for each gear *a little bit on redline* all the way up until 5/6th gear to see how much torque & horsepower you're getting? Or do you short shift to let's say 4th gear then that's when you go wot on the dyno to get your numbers?

ampire

iTrader: (12)

They go to 4th gear and then WOT (to a really high mph) since 4th gear is usually ~ 1:1 gearing.

As he said above, area under the curve is what really matters. Heres my Mustang's dyno with ~300whp peak



and heres some random person's s2000 with ~300whp peak



Note that my 4.6 3v v8 has a much flatter curve and produces more average power at any given rpm despite having the same peak power.

This is because the S2000 has a higher rev limit, it has a 2.2 liter F22C1 which produces power by increasing the rate at which it does work rather than increasing the amount of work, it has a higher rev limit, being able to reach low 8k rpm.

This is like being able to do less work at any given time but able to do it with greater frequency, as I said above power = work * time.

EvoTillIDie

iTrader: (1)

Thanks! These respnces are really helping me. I want to start learning and becoming an expert in reading & doing these myself. Also I see some dynos have more than one line. I'm guessing these are the runs per tune after trying the initial setup?