Ok. There is a difference in HP readings with the mustang dyno,dynojet fwd, dynojet awd & dyno dynamics. What is the margin of error between them? Which one has the most legit numbers?

 

All dyno numbers are bullshit. Which number is legit is kinda like which religion you think is best - it's very difficult to argue with someone who thinks differently from you.

Add on to the fact that almost all dynos have an option for a "correction factor" (often SAE, but not necessarily so) and you get a situation where it is pretty easy to lie with numbers, regardless of what dyno you are using.

My experience
Dynojet - "old" style (baseline)
Dynapack 2-4% less
Dynojet - "new" style 2-4% less
Land+Sea DynoMite Eddy current, new style 10-11% less
Mustang MD200 - 14-16% less
Land+Sea Water brake dyno 14-16% less
Dyno Dynamics - 17-19% less.

Dyno Dynamics numbers will vary a lot compared to other dynos according to how tight you strap the car down. Tire deformation, increased losses, etc.

Dynapacks also particularly seem to have larger differences at larger power outputs. Possibly the lack of wheel interface? I don't know.

Hope that helps.

 

that helps somewhat. But what about the difference beteween dynojet awd and front wheel drive? Is there a difference?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blundar &raquo;</TD></TR><TR><TD CLASS="quote">All dyno numbers are bullshit. Which number is legit is kinda like which religion you think is best - it's very difficult to argue with someone who thinks differently from you.

Add on to the fact that almost all dynos have an option for a "correction factor" (often SAE, but not necessarily so) and you get a situation where it is pretty easy to lie with numbers, regardless of what dyno you are using.

</TD></TR></TABLE>

Couldn't of said it any better than this.

 

So another words should I bump up my numbers (dynojet) or take my numbers with grain of salt then?

 

Dynojet numbers will be among the highest out there. Vehicle weight and 1/4mile traps speak a lot louder for me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blundar &raquo;</TD></TR><TR><TD CLASS="quote">Dynojet numbers will be among the highest out there. Vehicle weight and 1/4mile traps speak a lot louder for me.</TD></TR></TABLE>

I agree. I've seen some dynapaks read a lot higher than dynojets though... but there are a ton of factors. So yes, it's just a big pissing match.

Butt dyno ftw.

 

my numbers are UNcorrected

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blundar &raquo;</TD></TR><TR><TD CLASS="quote">Dynojet numbers will be among the highest out there. Vehicle weight and 1/4mile traps speak a lot louder for me.</TD></TR></TABLE>




That's the real way to tell. Who cares what the number is when the car runs well?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike93eh2 &raquo;</TD></TR><TR><TD CLASS="quote">my numbers are UNcorrected </TD></TR></TABLE>

HAHA, that's like saying you have the smallest dick and being proud of it
Uncorrected gives the highest HP

Like blundar said who gives a expletive about HP and torque as long as the dyno can measure them with precision (not accuracy) as this is what is important in tuning an engine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">HAHA, that's like saying you have the smallest dick and being proud of it
Uncorrected gives the highest HP

Like blundar said who gives a expletive about HP and torque as long as the dyno can measure them with precision (not accuracy) as this is what is important in tuning an engine.</TD></TR></TABLE>

oh.. i thought corrected was the ones that give the highest horsepower?

 

One important factor is that the numbers are more easily fudged on Dynopacks, Dyno Dynamics, and Mustang Dynos because there are a lot of user inputs than can be changed to affect the numbers. Not near as likely to happen on a dynojet. I definitely agree though, the track numbers don't lie. When it's all said and done, i dyno is just a tool. If all your tuning is done on the same dyno, then the number it spits out is almost irrelevant.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">
Uncorrected gives the highest HP
</TD></TR></TABLE>

What are you talking about? Correction Factor increases Dyno numbers 99% of the time son.

Unless the correction factor is like a .98 or something...I can count how many times that has happened on 1 hand, and I've dyno'd hundreds of cars.

 

When it's cold, uncorrected is higher, when it's hot, uncorrected is lower. The corrections correct for a "standard" day, with i think is around 70 deg. F

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">When it's cold, uncorrected is higher, when it's hot, uncorrected is lower. The corrections correct for a "standard" day, with i think is around 70 deg. F</TD></TR></TABLE>

But it also corrects for Barometric Pressure and Humidity...

 

Right, but at a given dyno, the main thing that changes the corrections is air temp.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">One important factor is that the numbers are more easily fudged on Dynopacks, Dyno Dynamics, and Mustang Dynos because there are a lot of user inputs than can be changed to affect the numbers. Not near as likely to happen on a dynojet. </TD></TR></TABLE>


i can show you many dynojet runs that are fudged. in fact, ive seen several different dj's weather stations go haywire, and add all sorts of stupid correction.

While there are more inputs on dynopacks, dd's and mustangs, you can still easily fudge dynojet numbers too

As said before, it really is only a tuning tool, ive used many different kinds of dynos, they they all have advantages and disadvantages.

you can not compare dyno charts between the manufactures, they will all read different.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Suprdave &raquo;</TD></TR><TR><TD CLASS="quote">

What are you talking about? Correction Factor increases Dyno numbers 99% of the time son.

Unless the correction factor is like a .98 or something...I can count how many times that has happened on 1 hand, and I've dyno'd hundreds of cars.</TD></TR></TABLE>



maybe up by you, but down here in the south east, this time of year, my correction factors are less than 1.0.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mase &raquo;</TD></TR><TR><TD CLASS="quote">

maybe up by you, but down here in the south east, this time of year, my correction factors are less than 1.0. </TD></TR></TABLE>

Why would your correction factors be less than 1 when it's pretty much the same temperature the entire year. If I dyno'd a car RIGHT now...while it's snowing and 30 degrees outside...it would be less than 1...but how often is someone going to Dyno a Car when it sucks this bad outside.

 

This has turned out to be a pretty informative thread. I guess track numbers mean more than dyno numbers.

 

maybe you can answer this question. Do dynojets awd read slightly differently than the fwd dynojets in you experience since you have the awd one?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Suprdave &raquo;</TD></TR><TR><TD CLASS="quote">

Why would your correction factors be less than 1 when it's pretty much the same temperature the entire year. If I dyno'd a car RIGHT now...while it's snowing and 30 degrees outside...it would be less than 1...but how often is someone going to Dyno a Car when it sucks this bad outside.</TD></TR></TABLE>

We do it all winter But our CFs are ALWAYS much bigger than 1. I have seen anywhere from 1.19 to 1.36 here in CO

 

I don't think I have EVER had a correction factor over 1. It is almost always under one, my uncorrected numbers are always higher on the particular dyno I use. I guess it just depends where you are located.

 

Jesus, 1.36! lol That's gotta make one feel like a hell of a tuner! haha

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Jesus, 1.36! lol That's gotta make one feel like a hell of a tuner! haha</TD></TR></TABLE>

People get disappointed with track times real quick after seeing corrected numbers lol. That's why I like to leave off the CF... with the dyno dynamics, people get disappointed with the numbers they see if they compare to other dynos, but then they wonder why they trap so high

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Drkaccrd &raquo;</TD></TR><TR><TD CLASS="quote">Ok. There is a difference in HP readings with the mustang dyno,dynojet fwd, dynojet awd & dyno dynamics. What is the margin of error between them? Which one has the most legit numbers?</TD></TR></TABLE>

What are you getting at? As has been said they (dyno's) are just tools to measure power and are NOT comparable. You CAN'T really compare runs from the same dyno done on different days. Best used to determine if the changes made during that session have improved power (among other factors that are measured) or not.

ALL too often folks try to compare their numbers to other folks in bench racing fashion to try and determine whose car is faster or what not... hooey. Don't get caught up in that stuff... just shows how much you don't know.

So... what is it you really want to know?