If you happen to wander around Sunway on certain weekends, you might find a group of people and a bunch of cars slowly lining up at the back of some alley, all heading towards a single garage. Dodgy as it might seem, they aren’t queuing up for the latest burger craze or to get some back alley Minion toy. In reality, they are just a bunch of petrol heads queuing up to satisfy their egos and curiosity. What sort you might say? Well the age old “whose car has more power” springs to mind.
As of late, I have seen more and more standard stock cars being tested out on these machines and there has been plenty of discussions going about the “mamak” tables, on which garage offers the best dyno, which is more accurate, as well as which ones portrays the best results (happy dyno!). I am definitely opening up a can of worms here. To make matters even more complicated, there are cases where engines are hand built, like those from the Nissan GTR. This also means the power output will be different making a direct car to car dyno comparison to also be different.
Recently I caught an episode on the web of how cars are made and found that for some car manufacturers have dyno machines installed in their respective factories. At the end of the production line, the cars are brought to these dyno machines and are tested prior to the car leaving the factory.
Anyway I digress.
The few key questions that people who hang around “mamaks” for their “Teh Tarik” sessions usually revolve around cars, the power it churns out or why is my dyno graph in this shape.
- Why are my dyno figures reporting more than the car manufacturer spec sheet?
- How much should I take into account for transmission losses?
- If I change certain parts (i.e. BMW’s powerkit for the diesel cars or the BMW performance exhaust), will I gain what is stated on those part spec sheet?
- Are the manufacturers spec sheet data actually accurate?
- Why is my friend getting more power from his car compared to mine? (especially if the cars are of the same make and model)
There can be many views a person can take to decipher the figures and charts as well as many school of thoughts on how to calculate the actual transmission loss of a car.
At the end of the day, here are 3 principles which I stick by when it comes to car dyno and dyno figures.
- All dyno machines can never produce the same results. From an engineering point of view, the re just way too many variables from ambient temperature, humidity, where the dyno machine is located (indoors/outdoors) and other factors
- You need to learn to take the results with a pinch of salt. Give or take an average of around 5-10(ps/hp) as well as learn to take into account the temperature and time you dyno your machine (mornings can be cooler)
- It is good to have a baseline dyno result so that as you progress in your car journey, you can track the changes of power output by constantly sticking to the same dyno machine/garage.
My advise? Make sure that the garage that you are sending your car to has the necessary experience and safety measures set up while you perform your car dyno. Trust me, after watching the videos below, you definitely would like to check twice and thrice especially when your car is strapped down onto the dyno machine.
http://www.youtube.com/watch?v=1bQ28XZyL5o
*This is the personal opinion of the writer and does not necessarily represent the views of Autofreaks.Net
