Home > About > Robs Blog > From the Vault – The great Dyno mass debate

Street Commodores 5/3/2009

Dynamometer, rolling road, the pump! There are many names for what people know as a dyno, just as there are many questions about the figures they produce. I have written before about dyno’s , their history and uses, however it is becoming increasingly frustrating dealing with the misinformation and fiction of the dyno figures that are bandied around on internet forums or when talking to customers that have been quoted figures by their mates or other workshops.

Firstly and foremost I want to put on the table that as a workshop owner people will think I have a vested interest in this debate and their right! I do! See I have a problem it’s called ethics it’s something my parents drilled into me as a young man and it stuck. I really like this industry and I am sick of the people who want to destroy it in the chase of a quick buck. All I am interested in and what the public should be interested in, is the facts! I have no interest in pumping up dyno figures. My company policy is quite the opposite, we are generally known in the industry as having a conservative dyno and there is no doubt this has cost me business over the years.

To explain further I would like to give you an example of what I am talking about. I can’t remember how many times a potential customer has rung me up and said how much for a cam only package on a VT-VZ Commodore and asked the mandatory how much power should I expect?  After explaining there is a lot of variables including, type of Cam, exhaust system, air intake, transmission wheels diameters etc, I would typically quote the cam spec and predict it would make around 285rwkw in a manual with all the right bolt-ons, the phone goes silent then I wait for it” but I was reading on the forums that the same combination got over 300rwkw”? My standard response is “I can’t comment on what other workshops make all I can do is tell you it will make on our dyno”.

The truth is if I wanted too, I could pretty much make the dyno read whatever power figure you wanted, there is so many variables that will impact on the power reading. There would be a lot people out there that wouldn’t believe me if I said by just going from 20” diameter wheel with a particular type of tire to a different set of 18” wheels could increase the power figure by as much as 25kw at the wheels! To be honest if didn’t see it with my own eyes I probably wouldn’t have believed it either, however when you think about it one of the biggest drive train losses in a chassis dyno is the friction between tyre and the roller so it does seem logical that the wheel and tyre combination will have an effect on the cars power reading.

Apart from the cars physical attributes there is also a number of dyno and operator factors that can affect the cars power reading, it is for this reason Dyno dynamics introduced the Shoot-out accredited dealer. They recognized their products reputation was being damaged and the public was getting confused and in some cases mislead by incompetent or dishonest dyno operators. There is a clear set of guide lines that a shoot-out accredited dealer must follow to ensure the power readings are correct and if followed Dyno dynamics state the power reading form one dyno to another should not vary by more than 1%. If you look at the recommended procedures they have also included a paragraph on ethical standards which states. The dyno operator must abide by a code of practice and if the company does not adhere to these guidelines, and decides to employ “Operator Techniques” and manipulate the process, Dyno Dynamics will issue the company with a warning. After 3 warnings, the company loses their Shootout Accreditation and that Dyno Dynamics expect dyno Operators to be honest and follow the required procedures in accordance with the Shootout Agreement. After reading the above it is pretty clear that even the manufacturer of the product recognizes there is a problem within the industry and that something needed to be done to protect the consumer.

Just as the dyno and the operator have reasonability to do the right thing so does the Industry as a whole, some of the stuff I read on the forums is just downright lies and the people writing it are either completely stupid or completely miss-informed. The problem is that unfortunately the guy or girl wanting to get some work done on their car goes to those forums only to find a mountain of information,  a lot of which is totally misleading. I would go as far as to say 60% of the dyno figures you see on forums are misleading in some form and I have proved this on many occasions when customers bring their car to us with a dyno sheet from another dyno only to find it reads considerably lower on our dyno.

It is simple, fudging and misquoting dyno figures is not good for the industry! It is my opinion it’s getting worse, maybe it’s due to the economy getting a little tighter and work drying up which is resulting in workshops pushing the numbers up to attract customers, who knows? One thing I do know is, not only does it set people up for disappointment, it creates an element of skepticism in the owners of modified vehicles and it will get to the point where most people will have little to no faith in Dyno figures which may or may not be a bad thing? After all my belief is that a dyno is a great tool for tuning but if your chasing numbers the only numbers that really count is what it runs at the track as that’s something that can’t be fudged…

See you at the track…

Rob Vickery

More Information:

Click here to learn how to read a dyno graph.

HPF Warranty

HPF power packages are warranted for the parts and services installed by HPF. Please contact us for more information.

Additional Notes

  • We recommend all vehicles coming to HPF for tuning run 98 Octane fuel. Please contact us if you have a need to use different fuel.
  • Power figures listed are estimated kilowatts at the flywheel based on results typically obtained by HPF on HPF’s dynos. Typically these are based of a manual vehicle with standard driveline and standard wheels and tyres. Actual power can vary based on each specific vehicle.
  • Modifications such as this package require the vehicle to be in excellent mechanical order.
  • We advise against increasing the power output substantially on high kilometer engines, if your engine has in excessive of 150,000kms please contact us to discuss options.
  • Whilst every attempt is made to ensure prices listed online are correct, they are subject to change at any time.
  • Additional parts may be required in some cases depending on the condition of the vehicle. Cost of these parts and additional labor required may incur additional cost.
Posted in Robs Blog

4 Comments please add yours...

  1. avatar

    All true. At the end of the day forum people suck it an just love the wank factor. Take it to the specialists. They do it all day and would know their shit… if ya poor dyno chart not big enough (spend more money)… ill be driving the 4hrs to bring my car here for sure

  2. avatar

    I got a cam package and according to hpf dyno readings I went from 201 to 273 rwkw in my vx ss and I have noticed a great difference in power just driving it. I have been told hpf dynos are dodgy but I don’t believe this is the case as my car flyes compared to before. Good read

  3. avatar

    people just forget that its measuring tool , as long as the b4 and afters are done on the same dyno.

    We have a saying

    “talk wins arguments in pubs , torque wins races”

  4. Good read and in all very very true even working at a holden dealer you hear all the same bs my mates making this and i have the same as him sick of it all all engines / drivelines are different you can dyno it all you want and it will change day to day with ambient air temp and so forth so like you said the only way to prove the power is at the track. have seen many of your engines / packages come through the workshop and i like the work done very clean hardly looks like you’ve touched them.
    pleased to see more people bringing the hole dyno problem up its time to silence the internet hero’s they are good for base info but don’t think you’ll get the same as them you never wwhat little differences they have

Post a Comment

Post with your Facebook account, or fill in below:

Connect with Facebook

HPF Group