Mustang Dynos are inaccurate?!?

[jimberg]

Hmm, I responded to your message in the other thread. I'll also post it here, too:

Originally posted by turbolx:
Well, since people here seem to be more content racing their dyno sheets than actaully going to the track to find out who's quicker, I don't see why I should bother with this debate much further.

One of the problems with making such vague statements is that anyone involved in the thread will take it to mean it was themselves to which you were referring. The quoting feature exists so that we can direct our responses to an individual. A good example is Vector's blanket statement, "You guys don't seem to understand what horsepower really is." I took this to mean that he felt I didn't understand what horsepower means. Then proceeded to give examples that were just wrong.

Originally posted by turbolx:I guess I wasted all that time in engineering school too, because someone says I'm wrong on the internet.

This is simply the nature of the Internet. I don't know you. I have no clue about what's in your mind other than what you communicate via messages. If I feel that someone makes a statement that is inaccurate or doesn't make sense I will challenge it. I expect them to do the same about anything I write, but they better be prepared to back up their challenge with some facts. Do you know that I'm not an engineer? That Unit's not an engineer? Maybe we are, just bad ones. Just having a degrees doesn't impress me that much since I don't have one and I still program circles around people who have them (Yeah, I'm not an engineer). This doesn't mean I have disrespect for a person who has a degree, just that I don't assume someone knows what they are talking about because they claim to have one.

Originally posted by turbolx:
The bottom line is as I stated before. The dyno (either one) is a tuning tool, not the ultimate judge of vehicle performance.

Of course not. There's power transfer from the wheels to the track which would be different based on the weight of the vehicle, suspension components, tire size, tire compound, track materials, track temperature, wind resistance, etc. All of which you are implying that the Mustang Dyno can simulate accurately. Will a Mustang Dyno allow the car to do a wheel stand or a burnout?

Originally posted by turbolx:
The trick is that the load bearing dynos can do a few more things that make the tuning process much easier when it comes to keeping motors together on the track.

If you wish to disagree with me on the merits of load bearing and vehicle simulation, fine. Just realize that this does not make me wrong.

I can only assume that this is directed at someone other than myself since I didn't disagree with you on this particular point other than the fact that it is possible that if the simulation could be flawed to the point that too much load is put on the car causing you to tune out performance that didn't need to be tuned out.

My other problem is with a prior statement of yours where you said "I will gladly put a car that makes 400rwhp on my MD1750 up against any car that makes 400rwhp Dynojet in a race." If you're implying that your car will win, tell us how it could with less actual horsepower. I'd say it can't unless it was inaccurately reporting power.

A dynamometer is a measuring device much like a torque wrench or a thermometer. No matter what torque wrench or thermometer you use, the readings they return should be the same when measuring the same thing. I suppose this doesn't really matter, though, if your only purpose is to make changes to the point that you know if you make more power than you did on a previous run.

It becomes a problem, though, if you are trying to make a statement about how much power you are able to gain by your tuning when comparing it to results of other tuners.

I guess the lesson to be gained from this debate is that if you tune your vehicle on a dyno to always tune it on the same dyno unless you're only concerned about the gains you make during the dyno session.

Oh, and about debating. Simple "I'm right, you're wrong" arguments don't really do much to further the knowledge of the readers. If I'm wrong, I like to be told why I'm wrong. Then I understand why and the people reading will understand why. If someone doesn't take the time to tell me why, I just assume that they don't know themselves.

I think I still have some questions on the table for turbolx. If you don't mind, I would like your learned response. See my previous message in the other dyno thread.



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351W 89 Mustang GT Convertible