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Truth in Numbers

Not All Dynos Are Created Equal

Truth in Numbers

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Filed under: Tips & Advice, European Car Testing
Truth in Numbers

Horsepower and torque figures are the most misunderstood and most abused numbers in the aftermarket automotive industry. There are so many different ways to both manipulate and falsify numbers while still appearing to be legitimate.

Perhaps you’ve found yourself in a situation like this yourself. You are looking to buy an aftermarket product, let say a tuning chip to raise the boost in your car and you have narrowed it down to two manufacturers. You thoroughly read each companies website and you’ve trolled the forums for reviews. You have researched the companies based on reputation, overall product reliability and the highest horsepower and torque numbers. You will not be persuaded by price or fancy add-on gadgets, because you want the most available horsepower and torque with the greatest reliability.

Company A

Chip: 208 hp and 262 ft-lbs of torque at the wheels

Company B

Chip: 204 hp and 241 ft-lbs of torque at the wheels

Based on the numbers the decision looks simple, the chip sold by company A produces greater horsepower and more torque. Although I wish it was just that simple, this is where you need to contact the company and ask them for as much data humanly possible. Here is a list of things that would be nice to know about the test car that produces the numbers that the companies claim:

1. What octane fuel was used when these numbers were obtained? 91, 93 or 94 octane?
2. Automatic or Manual transmission? What gear was the vehicle dyno’d in?
3. What was the outside temperature and humidity on the day of testing?
4. What was the operating temperatures(Intake & Coolant )of the vehicle?
5. What all the testing done the same day? Or done sequentially over a period of time and averaged?
6. How many dyno runs were performed? Which one is represented? How any times was it duplicated?
7. Was the car fully adapted?
8. If possible do you have timing and fuel logs?
9. Do you have a raw dyno numbers?
10. What brand and type of dyno did you use?
11. What were the stock horsepower and torques numbers? Where these baseline numbers obtained from the same dyno?
12. Was testing done on the same car – not just same make and model?

After obtaining some additional information from both companies, for example, their testing procedures, parameters and temperatures were within range and would not cause much variance and they both used the same brand of dyno etc, you could re-evaluate your data.

Company A

Stock:188 hp and 213 ft-lbs of torque at the wheels
Chip: 208 hp and 262 ft-lbs of torque at the wheels
-------------------------------------------------------------
Gains: 20 hp and 49 ft-lbs of torque at the wheels

Company B

Stock:181 hp and 193 ft-lbs of torque at the wheels
Chip: 204 hp and 241 ft-lbs of torque at the wheels
-------------------------------------------------------------
Gains: 23 hp and 47 ft-lbs of torque at the wheels

The additional data reveals that the gains from both chips are close if not exactly the same and the differences are so small that they should not even be considered. The numbers revealed that company B just started with a stock car that had less horsepower and torque from the factory. Numerous variables could have led to this fluctuation, i.e. when the last oil change occurred, how many miles are on the car, different brands of gas, or just motors in general as they come from the factory, etc. Remember that stock torque and hp numbers from the factory are an average since you could take 10 engines straight from the factory and get 5 sets of different numbers that are close in value. Every car is different so therefore the gains are not going to be identical, and the key thing is to make sure that the baseline and aftermarket tests were performed on the exact same car on the same day and the exact same dyno.

This holds true for any aftermarket car part whether it be a chip, exhaust system or intake. It is a common practice for many companies to produce numbers that help them sell products which include practices like dynoing a heat soaked motor for baseline vs. a cold motor for aftermarket values. To make an informed decision you need all the information from the manufacturer and do not rely on internet product fluff and forum speculation and bragging.


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