Dynojet V. Mustang?

[Dockboy]

:bang :bang :bang :bang Just as I thought, everyone thinks this is a tuning question, when I am asking a dyno question and noone understands..... If a substantial load cannot be placed on the engine, total power will never be seen, for all engines, gas or diesel, load determines output. This is torque, the part of the equasion that is paramount for power production. Without torque you have nothing. torque x rpm/5252= Horsepower. If you drive your truck around empty and never haul anything, how do you know its towing capabilities? Same goes for dynoeing, if maximum loading to the point of rpm reduction is not capable, then true power output is never achieved. There are variances from dyno to dyno. The variance from Dynojet to Mustang and other absorber type dynos is great. The point being made is, how have Dynojet numbers become so previlant, as gospel, when they cannot properly load the engine, and the dyno run lasts just a few seconds. Yes more power always wins, as long as you are all being tested on the same dyno, Has it become, we will take what we can get, and noone cares about accuracy and real potential. Seems like 2 pieces of equipment being within 20% of each other would cause some questions to be raised, as to the valaidity of either machine. Seems inertia numbers are always way above, what should be accepted as REAL numbers. Eddy Current and load dynos have a calibrated strain gauge, to determine torque output, when actual rpm is matched to torque, with proper loading, legitimate horsepower numbers are calculated.

:bang :bang :bang :bang :bang

It IS a tuning question because after all........A Dyno is merely a tuning tool!!

Your question of which one is more accurate can not really be fully answered because they each perform a different type of test. The only true relevence in the number either type produces anyway is the delta between numbers when you perform a tuning change. Otherwise they are just that..........Only Numbers.

As John stated above, if you are interested in tuning the performance for a static load like towing or sled pulling, use a load dyno. If the interest is in tuning for acceleration performance, use an inertia dyno. Either one can be considered the "true power output" depending on your application. Have you ever seen the data output from a Superflow? It has a tab that has a chart comparing what the numbers would be on each type of dyno.


And by the way.......A Dynojet does not care about torque!!! It measures the Horsepower it takes to accelerate a given fixed mass a predetermined time. It can however calculate the torque when you give it a rpm reference or know the used gearing ratio. But if neither one of these are provided, you will not know the torque.

 

[Timbeaux]

:bang :bang :bang :bang Just as I thought, everyone thinks this is a tuning question, when I am asking a dyno question and noone understands.....

No we understand completely,but in the case you mentioned, it was not the dyno's fault the truck did not make power......it was the tuning. If the truck were tuned correctly, it would fuel and make boost in most any situation. The upside is, that truck would be easy to drive in the rain because when the tires slip, they wont spin to the moon because there is no load.

 

[Timbeaux]

The point being made is, how have Dynojet numbers become so previlant, as gospel, when they cannot properly load the engine, and the dyno run lasts just a few seconds.

They can properly load a well tuned(street application)engine. Many have succeeded in doing so.

I have seen them load chargers on Darren Morrison's street truck that would make you deficate yourself. The truck made 857 HP that day 2 years ago,and a subsequent run down the track the next day calculated out to 85x Horsepower. I'll buy your arguement when it comes to big chargered-non streetable pulling trucks, but for street applications, the Dynojet seems to be the most user-friendly and repeatable tool out there because of it's simplicity. Sure, Superflows and others may be able to properly load a badly tuned engine and give you max HP numbers, but the truck that can light the turbo(s) on the dynojet will get to the stripe a helluva lot quicker. Plus, with the many variables with load type dynos, comparing numbers from dyno to dyno isnt much help.

 

[justinp20012500]

Can you obtain a large enough coefficient of friction to lay down big numbers on a "load" dyno?oke:op: