# Dyno



## MasterJetti08 (Mar 1, 2012)

Can anyone explain to me how to read a dyno sheet? Maybe post a pic of one and explain it to me or something. Ive looked at them before and I don't really get what I'm looking at.


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## mldouthi (Jun 26, 2010)

Blue line = torque curve
Red line = horsepower curve

x axis (horizontal) = RPM range
y axis (vertical) = hp (left), torque (right)


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## MasterJetti08 (Mar 1, 2012)

Ok so when they say it makes x amount of horsepower or torque at y ammount of rpms, the horsepower or torque ammount is taken from the highest point of the curve and then they just follow that straight down to see what rpms it was at when it made that?


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## Zoolook_ (Mar 17, 2012)

MasterJetti08 said:


> Ok so when they say it makes x amount of horsepower or torque at y ammount of rpms, the horsepower or torque ammount is taken from the highest point of the curve and then they just follow that straight down to see what rpms it was at when it made that?


Usually the highest point. 

But what this curve really tells you in the optimal point to change gears for either.


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## MasterJetti08 (Mar 1, 2012)

So how do you read he curve? I get how to find the max horsepower and torque. I don't get the rest.


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## TylerO28 (Jul 7, 2008)

Once you notice the line dropping, you want that to be your shift point. In order to continue building that power. Most people think redlining is going to get you ahead, but most cars start losing power that high...so it'd be best to shift before that line drops


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## MasterJetti08 (Mar 1, 2012)

Oh ok yea I figured that out just by driving. My Jetta makes much better power if I shift just before 5000 rpms then if i go higher. If the curve is more steep does that mean faster acceleration or what?


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## mldouthi (Jun 26, 2010)

MasterJetti08 said:


> Oh ok yea I figured that out just by driving. My Jetta makes much better power if I shift just before 5000 rpms then if i go higher. If the curve is more steep does that mean faster acceleration or what?


Steeper line means a faster increase in power, not acc.. Such as a car with a big turbo will have a big spike in power when the boost comes in were as a properly sized turbo or supercharger will give you a more linear curve. These given as examples.


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## MasterJetti08 (Mar 1, 2012)

Ok so you want a more linear right? Cause that would indicate more power all around instead of just in just one specific area?


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## jaja123 (Jan 17, 2011)

TylerO28 said:


> Once you notice the line dropping, you want that to be your shift point. In order to continue building that power. Most people think redlining is going to get you ahead, but most cars start losing power that high...so it'd be best to shift before that line drops


Hmm but if you shift too early your next gear may drop you out of the powerband. And at least for my car I made peak hp at the 6200 redline when I dynoed it. But my torque does drop when your past 5k and torque is what your butt dyno feels and its very noticeable when I rev past 5k(I still shift near redline though if I want max acceleration). Im still a little confused about hp vs torque vs acceleration.


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## MasterJetti08 (Mar 1, 2012)

Same here. I guess that is another question I should ask. What exactly is torque? I've never fully understood that.


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## itskohler (Jan 7, 2011)

Google it...


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## MasterJetti08 (Mar 1, 2012)

Why use google when I have the vortex?


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## itskohler (Jan 7, 2011)

Ugh. :facepalm:


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## mldouthi (Jun 26, 2010)

This is horsepower in relation to torque.

This is also the reason that the hp and tq curve on every dyno crosses at 5252 rpm. 












Power is the rate at which the torque is doing work. Technically, power = torque * rotation rate, but usually some constant is included to correct for a convenient choice of units. (stolen from some googled website)


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## itskohler (Jan 7, 2011)

mldouthi said:


> *(stolen from some googled website)*


 Funny how that works...


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## MasterJetti08 (Mar 1, 2012)

Yea...do you actually understand what that means? Cause I sure as hell don't...hence why I didn't google it...


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## itskohler (Jan 7, 2011)

Found this within 1 minute of a Google search...


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## mldouthi (Jun 26, 2010)

MasterJetti08 said:


> Yea...do you actually understand what that means? Cause I sure as hell don't...hence why I didn't google it...


Simplified, hp is a made up number derived from tq, and tq is rotational force.


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## thygreyt (Jun 7, 2009)

in reference to the other comment on the downpipe thread: yup.. the 2.5 is becomming more and mroe active! which is awesomeee!! 

in regards to this:

a book i read once defined TQ and HP as simple as this:

torque is how hard the car pulls, horsepower tells you how long that pull will last.

for example: a TDI has LOTS of TQ but low hp: 236ft-lbs of torque, yet only 140 hp.

it can be translated as: it will pull REALLY strongly, but it will only last a moment. the longer you rev it, the lesser it will pull.


also, in a dyno you are more interested on the area under the curve instead of the peak torque.

i suggest you read more. Tons of things can be apreciated on a torque graph (as mentioned, hp is a derivate of tq)


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## MasterJetti08 (Mar 1, 2012)

I guess that makes sense. I will have to look more into it.


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