smokeshow

iTrader: (16)

Definitely a copy and paste, but still nothing saying (and more importantly explaining) that a Mustang is more trustworthy. The fact remains that figuring power using a drum with a known mass and radius accelerated to a certain rpm in a given time frame is pretty fool proof. It can also be verified using a few simple calculations. Don't get me wrong, mustangs are great tools, in fact, too good...because the majority of people that purchase them don't spend enough time learning how they work. Hence, the vast difference in apparent power output of vehicles that dyno on them. I don't buy the 10% or 15% rule... One is right, one is wrong...simple. Ease of verification using a Dynojet and ease of tampering with output using a Mustang should be pretty conclusive as to which one is more likely to be accurate.

I await any article or paper documenting in detail the reason why a Mustang is to be trusted above all the rest.

Atomic

iTrader: (42)

So Ive had my truck at different times (and in different configurations) on a mustang, dynojet, and dynodynamics. My experience has been the mustang and dynojet shops were well established and employed good tuners, who I suspect spent a lot of time setting up their dynos because the numbers they spit out were pretty consistent with what my truck ran at the track considering trap speed and weight. The dynodynamics guy was not as familiar with his dyno and I found his to be 10-15% low compared to what a track time showed.

My point is they are all good tools, but like any tool its only as useful as the guy pushing the buttons.

gamble686

iTrader: (3)

The most common argument I have seen is related to how the dynojet setup was originally developed. The original Dynojet was indexed to a 1985 1200cc Yamaha V-Max. As a result a Dynojet will give high power readings for any vehicle with a lower spinning weight and vice versa. Which is to say, nearly all vehicles will have a different spining weights and therefore the numbers are inconsistent.

smokeshow

iTrader: (16)

What do you mean spinning weight? Any rotating mass on the vehicle doesn't matter because power loss in accelerating it is power lost regardless if its on the street or a dynamometer roller. Unless you mean back calculating to engine horsepower, but that's far more complicated to determine.

You can verify average horsepower through a certain rpm range using just wheel speed, roller mass and distribution, roller radius, and elapsed time. Punching in the numbers real quickly on a calculator would be plenty sufficient to determine there being as much as 10% difference in what the graph shows vs the calculated value. You can't do this with a Mustang though, as it measures torque and calculates horsepower and has an induced load, whereas a Dynojet measures horsepower and calculates torque.

gamble686

iTrader: (3)

You are absolutely right. I only meant to copy and paste the part about DJs being indexed to a Yamaha V-Max. Not the spinning weight.

blownescalade62

Lol you guys ask me to show you. So I did! Go back to looking at your over inflated dynojet sheets lol

George C....

Curious how fast have you been in the 1320

smokeshow

iTrader: (16)

You have provided no evidence, just claims. You've had ample opportunity to explain it, and nothing...

ZO6Ted

I don't have a dog in this fight because I've never bothered to dyno anything just go to the track and let it speak for itself, but for many years I have thought it was common knowledge or at least widely believed that the dynapak gave an inflated reading, a dynojet gave a correct reading usually and mustangs gave a low but reliable reading. Now I'm just confused. Think I'll have a Corona!

George C....

ive always used a wallace calculator with my times at track and it has always been right in the park of what a dynojet states


watch how a mustang dyno operator types in the wrong weight of a vehicle and not setup his weather station correctly and watch the numbers wonder