Dyno Cheating / How to create false figures with incorrect strapping | Roller Climbing

[@ARDEN440i]

Very interesting. Great video Warren. What kind of dyno do you use? Is it a Mustang or a Dynojet?

[@WGMotorworksYouTube]

Its a Dyno Dynamics - Dynotech :)

[@ARDEN440i]

@@WGMotorworksKZbin Ah nice. These kind of dynos usually add a bit of resistance to simulate driving on a road, so they tend to read out slightly lower, but more realistic power and torque figures. By far the best dyno available 👍🏾 In the US they refer to it as a "Mustang" dyno.

[@WGMotorworksYouTube]

Yeah, they are more accurate in our eyes, especially when making stock figures! - Dynojets that read WHP only read a lot higher, in fact - dyno dynamics has a 'comparison feature' to compare their WHP to Dynojet WHP

[@tunedbyrabbid]

DynoJet or Mustang is a separate brand of dyno not a type. You have three dyno types Inertia Dyno's, Braked Dyno's or a Hybrid of both. Inertia dynos just rely on a larger heavy mass and measuring the rate of change in speed of the mass people love to say how they're accurate as you know the mass of the roller but that not true..The roller isn't all the rotating mass, there is also wheels, shafts, gears clutches etc. This is the drive line mass which has inertia. DynoJet's are complete rubbish in the USA, rather than properly calculating drive line inertia they just added a fudge factor to increase the numbers on their original bike dyno. (Google DynoJet fudge factor) I think it was they measured 90WHP on a bike that was meant to be 120WHP with a brake. So the 33% fudge was input into their software so it popped out 120WHP. This fudge carried on to all their car dynos too. The problem with inertia dynos is they don't keep a constant acceleration rate so your error changes up and down with acceleration rates depending whether you've over or under calculated the total inertia of the dyno. As you add more powerful vehicles they accelerate the roller faster and end up with huge errors. All rolling roads have error but Dyno Dynamics gets as close as you can get to the real number. What you're seeing here is the amount of inertia assumed by the software is changed from what is rotated by the car. By removing the rear roller the inertia it has is no longer part of the total inertia of the rotating mass the car is pushing. The software still includes this as it has no idea the car has lifted and the extra power from the car is being transferred to the brake. So it's effectively counted twice. Dyno Dynamics hold a fixed acceleration rate whether you're 100 or 1000WHP and have a drive line inertia locked into the calculation. If the drive line inertia is wrong you'll get a the same error at 100WHP or 1000WHP whether it be 1HP or 5HP its comparable regardless of the power and the more power you make the smaller the error gets as a percentage. On a DynoJet there is no drive line inertia they just under read the rotating mass then fudge it with a percentage so the error is a percentage so if you have a 5% error at 100WHP that becomes 50HP at 1000WHP On a dyno dynamics you measure as much as you can with the brakes load cell and minimise the amount of inertia involved by restricting the acceleration rate with the brake. If you measure at steady state there is no inertia power reading and their is only brake power reading which is accurate WHP. If your power increases or decreases when you use a ramp or sweep test your total inertia is wrong. During a power run you're running a hybrid between a brake dyno and an inertia dyno. If you did a step test where you step at 100 or 500RPM intervals you could measure the vehicle at every single point in steady state with no inertia but that would be stressful and very heat intensive for the vehicle. And that's before we even begin to talk about fly wheel calculations.

[@230JS]

I also use Dynotech(Dyno Dynamics) at my workshop. Never miss a beat. Love it!

[@WGMotorworksYouTube]

Ours has been running for 4 years without any issues also! And consistent results

[@gnkVLCT]

AT and IT differences being far as well....

[@Scouse.Malinois]

This is true and false, you can cheat a dyno this way but there is also some tuners who purposely dyno this way and its not to cheat you, weather its the type of dyno or the way its calibrated I don't no but I've had my car dynoed both ways, at one dyno where it doesn't move and a different dyno where it climbs the front roller and the figures where basically the same

[@MotortunePhoB]

This video is relevant only for twin roller dynos, where these rollers are not mechanicaly connected/linked. Otherwise doesnt matter. Just potential traction issues will make the difference.

[@leehearsey]

nice motor that ;)

[@WGMotorworksYouTube]

Could do with some more power though :P

[@leehearsey]

@@WGMotorworksKZbin I'm sure it'll get some in the future 😋

[@robertolombardi3698]

Lovely M2 Lee, I had one in the beautiful Long beach blue.

[@leehearsey]

thanks mate, it is lovely shade :)

[@WGMotorworksYouTube]

@@leehearsey Not quite San Marino, but still up there :P